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Question 1
Incorrect
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A 68-year-old man is admitted to the gastroenterology ward with a 9-day history of cramping abdominal pain, fever and diarrhoea, opening his bowels up to 7 times per day. He has a past medical history of COPD and reports to have completed 2 courses of antibiotics to treat an exacerbation within the last 2 weeks.
After being diagnosed with a likely infection, the patient is started on oral vancomycin but shows little improvement. The treatment is then switched to fidaxomicin, but he still reports ongoing pain and diarrhoea even after completing the course.
What would be the most appropriate next step in managing this patient's condition?Your Answer: Intravenous vancomycin and intravenous metronidazole
Correct Answer: Oral vancomycin and intravenous metronidazole
Explanation:If the initial treatment of C. difficile with vancomycin or fidaxomicin is ineffective, the next step should be to administer oral vancomycin with or without intravenous metronidazole.
Clostridioides difficile is a type of bacteria that is commonly found in hospitals. It is a Gram positive rod that produces an exotoxin which can cause damage to the intestines, leading to a condition called pseudomembranous colitis. This bacteria usually develops when the normal gut flora is suppressed by broad-spectrum antibiotics, with second and third generation cephalosporins being the leading cause of C. difficile. Other risk factors include proton pump inhibitors. Symptoms of C. difficile include diarrhea, abdominal pain, and a raised white blood cell count. The severity of the infection can be determined using the Public Health England severity scale, which ranges from mild to life-threatening.
To diagnose C. difficile, a stool sample is tested for the presence of C. difficile toxin (CDT). Treatment for a first episode of C. difficile infection typically involves oral vancomycin for 10 days, with fidaxomicin or a combination of oral vancomycin and IV metronidazole being used as second and third-line therapies. Recurrent infections occur in around 20% of patients, increasing to 50% after their second episode. In such cases, oral fidaxomicin is recommended within 12 weeks of symptom resolution, while oral vancomycin or fidaxomicin can be used after 12 weeks. For life-threatening C. difficile infections, oral vancomycin and IV metronidazole are used, and surgery may be considered with specialist advice. Other therapies, such as bezlotoxumab and fecal microbiota transplant, may also be considered for preventing recurrences in certain cases.
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This question is part of the following fields:
- Infectious Diseases
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Question 2
Correct
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A 26-year-old male patient complains of painful ulcers on his penis shaft and dysuria for the past three days. He has never experienced such symptoms before. The clinical diagnosis suggests primary genital herpes. What is the best course of action for managing this condition?
Your Answer: Oral aciclovir
Explanation:Even if the presentation is delayed for up to 5 days, primary genital herpes infections require oral antiviral therapy.
Understanding Herpes Simplex Virus
Herpes simplex virus (HSV) is a common viral infection that affects humans. There are two strains of the virus, HSV-1 and HSV-2, which were previously thought to cause oral and genital herpes, respectively. However, there is now considerable overlap between the two strains. The primary infection may present with severe gingivostomatitis, while cold sores and painful genital ulceration are common features.
Management of HSV includes oral aciclovir for gingivostomatitis and genital herpes, and topical aciclovir for cold sores, although the evidence base for the latter is modest. Patients with frequent exacerbations may benefit from longer-term aciclovir. In pregnant women, a primary attack of herpes during pregnancy at greater than 28 weeks gestation may require elective caesarean section at term. Women with recurrent herpes who are pregnant should be treated with suppressive therapy and advised that the risk of transmission to their baby is low.
The cytopathic effect of HSV can be seen in Pap smears, which show multinucleated giant cells representing infection by the virus. The 3 M’s – multinucleation, margination of the chromatin, and molding of the nuclei – are characteristic features of HSV infection. Understanding the features and management of HSV is important for effective treatment and prevention of transmission.
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This question is part of the following fields:
- Infectious Diseases
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Question 3
Correct
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A 26-year-old man presents to the GUM clinic with penile discharge and dysuria for the past 5 days. Urethral swabs are taken and microscopy reveals the presence of diplococci. Sensitivities are not yet available, and he is diagnosed with gonorrhoea. What is the recommended initial treatment?
Your Answer: IM ceftriaxone
Explanation:Gonorrhoea is best treated with intramuscular ceftriaxone, and it is crucial to notify and treat sexual partners. All patients with gonorrhoea should undergo a test of cure after 2 weeks.
Understanding Gonorrhoea: Causes, Symptoms, Microbiology, and Management
Gonorrhoea is a sexually transmitted infection caused by the Gram-negative diplococcus Neisseria gonorrhoeae. It can occur on any mucous membrane surface, including the genitourinary tract, rectum, and pharynx. The incubation period of gonorrhoea is typically 2-5 days. Symptoms in males include urethral discharge and dysuria, while females may experience cervicitis leading to vaginal discharge. Rectal and pharyngeal infections are usually asymptomatic.
Immunisation against gonorrhoea is not possible, and reinfection is common due to antigen variation of type IV pili and Opa proteins. Local complications may develop, including urethral strictures, epididymitis, and salpingitis, which can lead to infertility. Disseminated infection may also occur, with gonococcal infection being the most common cause of septic arthritis in young adults.
Management of gonorrhoea involves the use of antibiotics. Ciprofloxacin used to be the treatment of choice, but there is now increased resistance to it. Cephalosporins are now more widely used, with a single dose of IM ceftriaxone 1g being the new first-line treatment. If ceftriaxone is refused, oral cefixime 400mg + oral azithromycin 2g should be used. Disseminated gonococcal infection (DGI) and gonococcal arthritis may also occur, with symptoms including tenosynovitis, migratory polyarthritis, and dermatitis. Later complications include septic arthritis, endocarditis, and perihepatitis.
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This question is part of the following fields:
- Infectious Diseases
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Question 4
Incorrect
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A 3-day-old infant delivered via caesarean section at 38 weeks gestation presents with limb hypoplasia, rudimentary digits, and microcephaly. What is the probable prenatal infection that the baby was exposed to?
Your Answer: Rubella
Correct Answer: Varicella zoster virus
Explanation:During pregnancy, if a woman shows signs of primary infection with varicella zoster, it is considered a classical indication. The risk to the fetus is highest before 20 weeks of gestation and can lead to skin scarring, limb underdevelopment, microcephaly, and eye defects. If there is any uncertainty about a pregnant woman’s history of chickenpox, she should be tested for varicella antibodies and given varicella zoster immunoglobulins if she is not immune. Cytomegalovirus infection during pregnancy can result in cerebral calcification, microcephaly, and sensorineural deafness. HIV does not pose any physical risk to the developing fetus, but there is a risk of perinatal transmission. Rubella infections during pregnancy are linked to deafness, congenital cataracts, and cardiac complications.
Chickenpox exposure in pregnancy can pose risks to both the mother and fetus, including fetal varicella syndrome. Post-exposure prophylaxis (PEP) with varicella-zoster immunoglobulin (VZIG) or antivirals should be given to non-immune pregnant women, with timing dependent on gestational age. If a pregnant woman develops chickenpox, specialist advice should be sought and oral aciclovir may be given if she is â„ 20 weeks and presents within 24 hours of onset of the rash.
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This question is part of the following fields:
- Infectious Diseases
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Question 5
Correct
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A teenager returns from a backpacking holiday in South America, having developed abdominal pain, diarrhoea and fevers one week before his return. On examination, he has a fever of 38.5 °C and diffuse abdominal pain. Stool microscopy shows pus and red blood cells; culture is awaited.
Which of the following is the most likely organism?Your Answer: Salmonella species
Explanation:Common Causes of Gastroenteritis in Travellers
Travellers are at risk of contracting various infections that can cause gastroenteritis. Salmonella species, transmitted through contaminated food or beverages, can cause non-typhoidal enterocolitis, non-typhoidal focal disease, or typhoid fever. Rotavirus, which causes self-limited gastroenteritis, typically presents with anorexia, low-grade fever, and watery, bloodless diarrhea. Plasmodium falciparum, a parasite that causes malaria, can be detected through blood films. Norovirus, the most common cause of epidemic non-bacterial gastroenteritis, presents with nausea, vomiting, watery non-bloody/non-purulent diarrhea, and low-grade fever. Vibrio cholerae, which causes cholera, is transmitted through contaminated water or food and can cause severe watery diarrhea, vomiting, and dehydration. It is important to consider these potential causes when diagnosing gastroenteritis in returning travellers.
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This question is part of the following fields:
- Infectious Diseases
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Question 6
Correct
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A 32-year-old woman who lives with her husband comes to you for advice. She has been experiencing anal discharge and itching for the past 4 days. She also has some symptoms of painful urination. A urethral smear shows intracellular diplococci.
What is the most probable infectious agent that matches this clinical presentation?Your Answer: Neisseria gonorrhoeae
Explanation:Common Sexually Transmitted Infections and Diagnostic Methods
Sexually transmitted infections (STIs) are a major public health concern worldwide. Here are some common STIs and their diagnostic methods:
Neisseria gonorrhoeae: This bacterium causes gonorrhoea, which is a purulent infection of the mucous membranes. In men, symptoms include urethritis, acute epididymitis, and rectal infection. A Gram stain is the method of choice for detecting gonorrhoea in symptomatic men.
Treponema pallidum: This spirochaete bacterium causes syphilis. Serologic testing is the standard method of detection for all stages of syphilis.
Chlamydia trachomatis: This bacterium is an obligate intracellular micro-organism that infects squamocolumnar epithelial cells. Nucleic acid amplification testing (NAAT) is the most sensitive test for detecting C. trachomatis infection, and a urine sample is an effective specimen for this test.
Herpes simplex virus type 1 (HSV-1): This virus is typically associated with orofacial disease. Tissue culture isolation and immunofluorescent staining can be used to diagnose HSV-1.
Herpes simplex virus type 2 (HSV-2): This virus is typically associated with urogenital disease. Tissue culture isolation and immunofluorescent staining can be used to diagnose HSV-2.
Common STIs and Their Diagnostic Methods
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This question is part of the following fields:
- Infectious Diseases
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Question 7
Incorrect
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A 42-year-old woman presents with increasing fatigue and cough. She attributes it to the stress she experienced during a recent business trip to Italy. Since then, she has been feeling feverish and tired, and her cough started two days ago. She has no medical history, but she admits to having had unprotected sex recently. A chest x-ray reveals consolidation in both lung bases. Her blood tests are as follows:
- White blood cell count: 12 * 10^9/l
- Hemoglobin: 135 g/l
- C-reactive protein: 145 mg/l
- Sodium: 125 mmol/l
- Potassium: 4.7 mmol/l
- Alanine transaminase: 87 IU/l
What is the causative organism?Your Answer: Mycoplasma pneumoniae
Correct Answer: Legionella pneumophilia
Explanation:Legionella is characterized by typical symptoms such as flu-like illness, dry cough, confusion, and relative bradycardia. Blood tests may reveal hyponatremia.
Outbreaks of Legionella pneumonia often occur in communities with shared water supplies, as hinted at in the question with the reference to the recent conference in Spain. This type of pneumonia frequently affects both lungs, as seen in the question. Additionally, Legionella can cause abnormal liver function tests and hyponatremia, which can lead to confusion in some cases, although this is not mentioned in the question.
The mention of unprotected sex is a distractor, as it would take years for HIV infection to make a person susceptible to infections like TB and Pneumocystis jiroveci.
Legionnaire’s Disease: Symptoms, Diagnosis, and Management
Legionnaire’s disease is a type of pneumonia caused by the Legionella pneumophilia bacterium, which is commonly found in water tanks. It is not transmitted from person to person. Symptoms of the disease include flu-like symptoms such as fever, dry cough, confusion, and lymphopaenia. Other features include relative bradycardia, hyponatraemia, and deranged liver function tests. Pleural effusion is seen in around 30% of patients.
Diagnosis of Legionnaire’s disease can be done through a urinary antigen test. Treatment involves the use of erythromycin or clarithromycin. Chest x-ray features of the disease are non-specific but may include patchy consolidation with a mid-to-lower zone predominance.
Compared to Mycoplasma pneumonia, Legionnaire’s disease has distinct differences in symptoms and diagnostic methods. It is important to be aware of the potential for Legionnaire’s disease in cases where water tanks or air-conditioning systems may be involved, as early diagnosis and treatment can lead to better outcomes.
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This question is part of the following fields:
- Infectious Diseases
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Question 8
Incorrect
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A 36-year-old man who is HIV positive presents with flat purple patches on his mouth and legs. During examination, his doctor observes violaceous, purple papular lesions on his calves and feet, leading to a suspicion of Kaposi's sarcoma. What is the cause of this condition?
Your Answer: Human papilloma virus
Correct Answer: Human herpes virus 8
Explanation:HHV-8 (human herpes virus 8) is the cause of Kaposi’s sarcoma, which is commonly found in HIV patients. Parvovirus B19 causes fifths disease or slapped cheek syndrome in children and can also lead to foetal hydrops. The human papilloma virus is linked to genital warts and cervical cancer. Epstein-Barr virus causes infectious mononucleosis (glandular fever) and is associated with Hodgkin’s lymphoma, Burkitt’s lymphoma, gastric cancer, and nasopharyngeal carcinoma.
Kaposi’s Sarcoma in HIV Patients
Kaposi’s sarcoma is a type of cancer that is commonly seen in patients with HIV. It is caused by the human herpes virus 8 (HHV-8) and is characterized by the appearance of purple papules or plaques on the skin or mucosa. These lesions may later ulcerate, causing discomfort and pain. In some cases, respiratory involvement may occur, leading to massive haemoptysis and pleural effusion.
Treatment for Kaposi’s sarcoma typically involves a combination of radiotherapy and resection. This can help to reduce the size of the lesions and prevent further spread of the cancer. However, it is important to note that Kaposi’s sarcoma can be a serious and potentially life-threatening condition, particularly in patients with HIV. As such, it is important for individuals with HIV to be regularly screened for this condition and to seek prompt medical attention if any symptoms are present.
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This question is part of the following fields:
- Infectious Diseases
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Question 9
Incorrect
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A 28-year-old female is admitted to the Medical Admissions Unit with symptoms of neck stiffness, photophobia, and fever. No rash is present, and her GCS is 15. Upon lumbar puncture, her CSF shows increased opening pressure and turbidity, with a raised white cell count and low glucose. Ceftriaxone is initiated, but what additional treatment is necessary to enhance outcomes?
Your Answer: Prednisolone
Correct Answer: Dexamethasone
Explanation:The patient’s presentation and CSF results strongly suggest bacterial meningitis, for which appropriate antibiotic therapy has been initiated. To improve neurological outcomes and reduce the risk of sequelae such as deafness, dexamethasone is the recommended additional treatment. However, it should be noted that dexamethasone is contraindicated in cases of septic shock or meningococcal septicaemia. Antivirals such as aciclovir are not indicated in bacterial meningitis, while fluconazole, an anti-fungal, is also not appropriate. Prednisolone has no role in the treatment of meningitis.
The investigation and management of suspected bacterial meningitis are intertwined due to the potential negative impact of delayed antibiotic treatment. Patients should be urgently transferred to the hospital, and an ABC approach should be taken initially. A lumbar puncture should be delayed in certain circumstances, and IV antibiotics should be given as a priority if there is any doubt. The bloods and CSF should be tested for various parameters, and prophylaxis should be offered to households and close contacts of patients affected with meningococcal meningitis.
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This question is part of the following fields:
- Infectious Diseases
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Question 10
Correct
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A 32-year-old male patient visits the sexual health clinic complaining of a recent genital lesion. The patient reports experiencing severe pain and first noticed the lesion one week ago. He admits to engaging in unprotected sexual activity with multiple partners within the past three months. Upon examination, a deep ulcer with a ragged border is observed on the penis shaft, accompanied by tenderness and inguinal lymphadenopathy. What is the probable diagnosis?
Your Answer: Chancroid
Explanation:The man’s ulcer appears to be caused by chancroid, which is known for causing deep and painful genital ulcers accompanied by inguinal lymphadenopathy. Gonorrhoea is an unlikely diagnosis as it typically presents with penile discharge and no ulceration. Herpes simplex can also cause painful genital ulcers, but they are usually multiple and superficial, and inguinal lymphadenopathy is not as common as with chancroid. Lymphogranuloma venereum causes painless ulceration that heals quickly, while primary syphilis causes a painless ulcer called a chancre.
Understanding Chancroid: A Painful Tropical Disease
Chancroid is a disease that is commonly found in tropical regions and is caused by a bacterium called Haemophilus ducreyi. This disease is characterized by the development of painful genital ulcers that are often accompanied by painful swelling of the lymph nodes in the groin area. The ulcers themselves are typically easy to identify, as they have a distinct border that is ragged and undermined.
Chancroid is a disease that can be quite painful and uncomfortable for those who are affected by it.
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This question is part of the following fields:
- Infectious Diseases
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Question 11
Incorrect
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Which of the following characteristics is the least typical of Trichomonas vaginalis?
Your Answer: Urethritis in men
Correct Answer:
Explanation:A pH level greater than 4.5 is linked to Trichomonas vaginalis and bacterial vaginosis.
Understanding Trichomonas vaginalis and its Comparison to Bacterial Vaginosis
Trichomonas vaginalis is a type of protozoan parasite that is highly motile and flagellated. It is known to cause trichomoniasis, which is a sexually transmitted infection. The infection is characterized by symptoms such as offensive, yellow/green, frothy vaginal discharge, vulvovaginitis, and strawberry cervix. The pH level is usually above 4.5, and in men, it may cause urethritis.
To diagnose trichomoniasis, a wet mount microscopy is conducted to observe the motile trophozoites. The treatment for trichomoniasis involves oral metronidazole for 5-7 days, although a one-off dose of 2g metronidazole may also be used.
When compared to bacterial vaginosis, trichomoniasis has distinct differences. Bacterial vaginosis is caused by an overgrowth of bacteria in the vagina, while trichomoniasis is caused by a protozoan parasite. The symptoms of bacterial vaginosis include a thin, grayish-white vaginal discharge with a fishy odor, and a pH level above 4.5. Unlike trichomoniasis, bacterial vaginosis is not considered a sexually transmitted infection.
In conclusion, understanding the differences between trichomoniasis and bacterial vaginosis is crucial in diagnosing and treating these conditions effectively. Proper diagnosis and treatment can help prevent complications and improve overall health and well-being.
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This question is part of the following fields:
- Infectious Diseases
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Question 12
Correct
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A 35-year-old man with rheumatoid arthritis and on long-term methotrexate visits the clinic with concerns about his recent exposure to chickenpox. He attended a family gathering where a child with chickenpox was present, but he cannot recall if he had the illness as a child. He is seeking advice on whether he needs any treatment.
What is the best course of action to take next?Your Answer: She should receive VZIG if antibody tests are negative
Explanation:Patients who are on long-term steroids or methotrexate and are immunosuppressed should be given VZIG if they are exposed to chickenpox and have no antibodies to varicella. The correct course of action is to conduct antibody testing to determine if the patient is negative, and if so, administer VZIG to protect them from potentially developing a serious chickenpox infection. Although a chickenpox vaccine exists, it is not part of the routine childhood vaccination schedule and is not recommended for immunosuppressed individuals due to its live nature. IV aciclovir can be given for chickenpox infection in immunocompromised individuals, but VZIG is more appropriate as it can help prevent the infection from manifesting. Administering VZIG once the patient has already shown symptoms of chickenpox is too late, as it has no therapeutic benefit at that point. While oral aciclovir can be given prophylactically or to reduce the severity of symptoms, VZIG is more appropriate for immunosuppressed patients who are at high risk of severe chickenpox infection.
Managing Chickenpox Exposure in At-Risk Groups
Chickenpox is usually a mild illness in children with normal immune systems, but it can cause serious systemic disease in at-risk groups. Pregnant women and their developing fetuses are particularly vulnerable. Therefore, it is crucial to know how to manage varicella exposure in these special groups.
To determine who would benefit from active post-exposure prophylaxis, three criteria should be met. Firstly, there must be significant exposure to chickenpox or herpes zoster. Secondly, the patient must have a clinical condition that increases the risk of severe varicella, such as immunosuppression, neonates, or pregnancy. Finally, the patient should have no antibodies to the varicella virus. Ideally, all at-risk exposed patients should have a blood test for varicella antibodies. However, this should not delay post-exposure prophylaxis past seven days after initial contact.
Patients who meet the above criteria should be given varicella-zoster immunoglobulin (VZIG). Managing chickenpox exposure in pregnancy is an important topic that requires more detailed discussion, which is covered in a separate entry in the textbook.
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This question is part of the following fields:
- Infectious Diseases
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Question 13
Correct
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A 43-year-old patient presents to the emergency department with complaints of feeling generally unwell. He reports experiencing body aches and waking up in a cold sweat at night. Upon examination, you observe injection marks on the antecubital fossa. His vital signs reveal a temperature of 38.1ÂșC, heart rate of 122 bpm, blood pressure of 110/90 mmHg, respiratory rate of 18/min, and oxygen saturation of 98%. You urgently order blood cultures and an echocardiogram. Based on the diagnosis, which site is most likely affected?
Your Answer: Tricuspid valve
Explanation:The tricuspid valve is the valve most commonly affected by infective endocarditis in intravenous drug users.
Aetiology of Infective Endocarditis
Infective endocarditis is a condition that affects patients with previously normal valves, rheumatic valve disease, prosthetic valves, congenital heart defects, intravenous drug users, and those who have recently undergone piercings. The strongest risk factor for developing infective endocarditis is a previous episode of the condition. The mitral valve is the most commonly affected valve.
The most common cause of infective endocarditis is Staphylococcus aureus, particularly in acute presentations and intravenous drug users. Historically, Streptococcus viridans was the most common cause, but this is no longer the case except in developing countries. Streptococcus mitis and Streptococcus sanguinis are the two most notable viridans streptococci, commonly found in the mouth and dental plaque. Coagulase-negative Staphylococci such as Staphylococcus epidermidis are the most common cause of endocarditis in patients following prosthetic valve surgery.
Streptococcus bovis is associated with colorectal cancer, with the subtype Streptococcus gallolyticus being most linked to the condition. Non-infective causes of endocarditis include systemic lupus erythematosus and malignancy. Culture negative causes may be due to prior antibiotic therapy or infections caused by Coxiella burnetii, Bartonella, Brucella, or HACEK organisms (Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, Kingella).
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This question is part of the following fields:
- Infectious Diseases
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Question 14
Incorrect
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A 42-year-old male complains of difficulty breathing after experiencing flu-like symptoms for a week. He has a dry cough and no chest discomfort. A chest x-ray reveals bilateral consolidation, and he has red rashes on his limbs and torso. Which test is most likely to provide a definitive diagnosis?
Your Answer: Sputum culture
Correct Answer: Serology for Mycoplasma
Explanation:A diagnosis of Mycoplasma can be made based on symptoms such as flu-like symptoms, bilateral consolidation, and erythema multiforme. The most suitable diagnostic test for this condition is Mycoplasma serology.
Mycoplasma pneumoniae: A Cause of Atypical Pneumonia
Mycoplasma pneumoniae is a type of bacteria that causes atypical pneumonia, which is more common in younger patients. This disease is associated with various complications such as erythema multiforme and cold autoimmune haemolytic anaemia. Epidemics of Mycoplasma pneumoniae typically occur every four years. It is important to recognize atypical pneumonia because it may not respond to penicillins or cephalosporins due to the bacteria lacking a peptidoglycan cell wall.
The disease usually has a gradual onset and is preceded by flu-like symptoms, followed by a dry cough. X-rays may show bilateral consolidation. Complications may include cold agglutinins, erythema multiforme, erythema nodosum, meningoencephalitis, Guillain-Barre syndrome, bullous myringitis, pericarditis/myocarditis, and gastrointestinal and renal problems.
Diagnosis is generally made through Mycoplasma serology and a positive cold agglutination test. Management involves the use of doxycycline or a macrolide such as erythromycin or clarithromycin.
In comparison to Legionella pneumonia, which is caused by a different type of bacteria, Mycoplasma pneumoniae has a more gradual onset and is associated with different complications. It is important to differentiate between the two types of pneumonia to ensure appropriate treatment.
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This question is part of the following fields:
- Infectious Diseases
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Question 15
Correct
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A 35-year-old man presents to his family doctor after a trip to Southeast Asia. He and his colleagues frequently ate at street food stalls during their trip, often consuming seafood. He complains of feeling unwell, loss of appetite, yellowing of the skin and dark urine. He had a fever initially, but it disappeared once the jaundice appeared. During the examination, he has an enlarged liver and tenderness in the upper right quadrant. His ALT and AST levels are ten times the upper limit of normal, while his bilirubin level is six times the upper limit of normal, but his ALP is only slightly elevated. What is the most probable diagnosis?
Your Answer: Hepatitis A
Explanation:The patient’s history of foreign travel suggests that the most likely diagnosis is Hepatitis A. This virus is typically contracted through ingestion of contaminated food, particularly undercooked shellfish. While rare, outbreaks of Hepatitis A can occur worldwide, especially in resource-poor regions. Symptoms usually appear 2-6 weeks after exposure and can be more severe in older patients. Liver function tests often show elevated levels of ALT and AST. Diagnosis is confirmed through serologic testing for IgM antibody to HAV. Treatment involves supportive care and management of complications. Salmonella infection, Hepatitis B, gallstones, and pancreatic carcinoma are less likely diagnoses based on the patient’s symptoms and clinical presentation.
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This question is part of the following fields:
- Infectious Diseases
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Question 16
Correct
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A 28-year-old woman presents to the Emergency Department with a one week history of cough and increasing shortness of breath over the past 48 hours. She also reports fever, headache, anorexia, and chills. Upon examination, she appears slightly pale and confused. Her vital signs reveal a pulse of 136/min, blood pressure of 96/64 mmHg, respiratory rate of 32/min, and oxygen saturation of 89% on room air. Lung auscultation reveals reduced breath sounds in the left lower lung with some coarse crackles. Blood cultures are taken and the patient is cannulated. High flow oxygen is administered and a fluid challenge is ordered by the nurse. What is the most appropriate next step?
Your Answer: Prescribe broad spectrum intravenous antibiotics
Explanation:If the patient’s condition worsens, ITU may be consulted. However, before referring the patient, it is important to determine if she has already received basic sepsis care. Although studies have explored the use of steroids in sepsis, they are not presently recommended due to an increase in mortality.
Understanding Sepsis: Classification and Management
Sepsis is a life-threatening condition caused by a dysregulated host response to an infection. In recent years, the classification of sepsis has changed, with the old category of severe sepsis no longer in use. Instead, the Surviving Sepsis Guidelines now recognize sepsis as life-threatening organ dysfunction caused by a dysregulated host response to infection, and septic shock as a more severe form of sepsis. The term ‘systemic inflammatory response syndrome (SIRS)’ has also fallen out of favor.
To manage sepsis, it is important to identify and treat the underlying cause of the infection and support the patient regardless of the cause or severity. However, if any red flags are present, the ‘sepsis six’ should be started immediately. This includes administering oxygen, taking blood cultures, giving broad-spectrum antibiotics, giving intravenous fluid challenges, measuring serum lactate, and measuring accurate hourly urine output.
NICE released its own guidelines in 2016, which focus on the risk stratification and management of patients with suspected sepsis. For risk stratification, NICE recommends using red flag and amber flag criteria. If any red flags are present, the sepsis six should be started immediately. If any amber flags are present, the patient should be closely monitored and managed accordingly.
To help identify and categorize patients, the Sequential (Sepsis-Related) Organ Failure Assessment Score (SOFA) is increasingly used. The score grades abnormality by organ system and accounts for clinical interventions. A SOFA score of 2 or more reflects an overall mortality risk of approximately 10% in a general hospital population with suspected infection. Even patients presenting with modest dysfunction can deteriorate further, emphasizing the seriousness of this condition and the need for prompt and appropriate intervention.
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This question is part of the following fields:
- Infectious Diseases
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Question 17
Correct
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A 31-year-old female patient visits her doctor with complaints of feeling unwell for the past week. She reports experiencing headaches and mild abdominal discomfort. She denies having any diarrhea but mentions severe constipation. Recently, she returned from a 3-week trip to India. During the examination, her temperature is recorded as 38.5ÂșC, and she appears bloated. Additionally, a sparse macular rash is observed on her chest. What is the probable causative agent for this presentation?
Your Answer: Salmonella typhi
Explanation:While salmonella can cause diarrhoea, typhoid fever is more likely to result in constipation. This is a typical symptom of typhoid fever, along with the appearance of rose spots. It’s important to note that constipation can be a significant indicator of this illness. In contrast, Campylobacter jejuni infection usually causes bloody diarrhoea and abdominal pain. E. coli is a common cause of watery diarrhoea, but certain strains like E. coli O157:H7 can lead to severe abdominal cramping, vomiting, and bloody diarrhoea. Giardiasis can cause similar symptoms such as bloating and abdominal pain, but it usually results in chronic diarrhoea. Shigellosis typically causes abdominal pain and diarrhoea, which may or may not be bloody.
Enteric fever, also known as typhoid or paratyphoid, is caused by Salmonella typhi and Salmonella paratyphi respectively. These bacteria are not normally found in the gut and are transmitted through contaminated food and water or the faecal-oral route. The symptoms of enteric fever include headache, fever, and joint pain, as well as abdominal pain and distension. Constipation is more common in typhoid than diarrhoea, and rose spots may appear on the trunk in some patients. Complications can include osteomyelitis, gastrointestinal bleeding or perforation, meningitis, cholecystitis, and chronic carriage. Chronic carriage is more likely in adult females and occurs in approximately 1% of cases.
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This question is part of the following fields:
- Infectious Diseases
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Question 18
Incorrect
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A 30-year-old male arrives at the emergency department following a brawl at a local bar. He appears to be heavily intoxicated and is loudly claiming that he was bitten on the hand while attempting to throw a punch. Upon examination, there is evidence of a bite mark on his right hand that has broken the skin but has not caused any bleeding. The wound site shows no signs of redness, swelling, necrotic tissue, or discharge. Despite being disruptive and agitated, the man is otherwise stable and does not have a fever. What is the most appropriate course of action for managing his condition?
Your Answer: Wound irrigation and debridement only
Correct Answer: Co-amoxiclav
Explanation:Co-amoxiclav is the appropriate antibiotic for treating human bites, as well as animal bites. If a human bite breaks the skin and draws blood, antibiotics should be administered. In the scenario provided, the man was bitten in a high-risk area, which includes the hands, feet, face, genitals, skin overlying cartilaginous structures, or an area of poor circulation. Even if the bite did not draw blood, antibiotics should still be considered if the person is at high risk or if the bite is in a high-risk area. Co-amoxiclav is the first choice antibiotic for prophylaxis and treatment of human and animal bites. If the patient has a penicillin allergy or if co-amoxiclav is not suitable, doxycycline with metronidazole is the preferred alternative. Flucloxacillin is not effective in treating human and animal bites. If there is discharge present from the wound site, a swab should be taken for microbiological sampling, and antibiotic choice can be adjusted based on the results. Initial wound management should include removing foreign bodies, irrigating the site, and debridement, especially if the wound is dirty. Pain management should also be provided. However, due to the location of the bite in a high-risk area, antibiotics are necessary.
Animal and Human Bites: Causes and Management
Animal and human bites are common injuries that can lead to infections caused by various microorganisms. Dogs and cats are the most common animals involved in bites, with Pasteurella multocida being the most commonly isolated organism. On the other hand, human bites can cause infections from both aerobic and anaerobic bacteria, including Streptococci spp., Staphylococcus aureus, Eikenella, Fusobacterium, and Prevotella.
To manage animal and human bites, it is important to cleanse the wound thoroughly. Puncture wounds should not be sutured closed unless there is a risk of cosmesis. The current recommendation for treatment is co-amoxiclav, but if the patient is allergic to penicillin, doxycycline and metronidazole are recommended. It is also important to consider the risk of viral infections such as HIV and hepatitis C in human bites.
In summary, animal and human bites can lead to infections caused by various microorganisms. Proper wound cleansing and appropriate antibiotic treatment are essential in managing these injuries. Additionally, healthcare providers should consider the risk of viral infections in human bites.
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This question is part of the following fields:
- Infectious Diseases
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Question 19
Incorrect
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A 67-year-old man presents to the emergency department with a productive cough of green sputum. He has a history of COPD and is an active smoker. Upon examination, he is wheezy bilaterally and saturating at 94% on room air. A chest X-ray shows no signs of consolidation. The following blood tests were obtained:
CRP 26 mg/L (< 5)
Na+ 133 mmol/L (135 - 145)
K+ 3.6 mmol/L (3.5 - 5.0)
Bicarbonate 34 mmol/L (22 - 29)
Urea 6 mmol/L (2.0 - 7.0)
Creatinine 100 ”mol/L (55 - 120)
What is the most likely causative organism for this clinical presentation?Your Answer: Moraxella catarrhalis
Correct Answer: Haemophilus infuenzae
Explanation:Haemophilus influenzae is the most frequent organism responsible for causing infective exacerbations of COPD, as evidenced by this man’s productive cough, increased shortness of breath, and wheezing.
Acute exacerbations of COPD are a common reason for hospital visits in developed countries. The most common causes of these exacerbations are bacterial infections, with Haemophilus influenzae being the most common culprit, followed by Streptococcus pneumoniae and Moraxella catarrhalis. Respiratory viruses also account for around 30% of exacerbations, with human rhinovirus being the most important pathogen. Symptoms of an exacerbation include an increase in dyspnea, cough, and wheezing, as well as hypoxia and acute confusion in some cases.
NICE guidelines recommend increasing the frequency of bronchodilator use and giving prednisolone for five days. Antibiotics should only be given if sputum is purulent or there are clinical signs of pneumonia. Admission to the hospital is recommended for patients with severe breathlessness, acute confusion or impaired consciousness, cyanosis, oxygen saturation less than 90%, social reasons, or significant comorbidity.
For severe exacerbations requiring secondary care, oxygen therapy should be used with an initial saturation target of 88-92%. Nebulized bronchodilators such as salbutamol and ipratropium should also be administered, along with steroid therapy. IV hydrocortisone may be considered instead of oral prednisolone, and IV theophylline may be used for patients not responding to nebulized bronchodilators. Non-invasive ventilation may be used for patients with type 2 respiratory failure, with bilevel positive airway pressure being the typical method used.
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This question is part of the following fields:
- Infectious Diseases
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Question 20
Correct
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A 65-year-old patient with chronic obstructive pulmonary disease (COPD) who continues to smoke is housebound due to his disability.
Which of the following immunisations should he receive on a yearly basis?Your Answer: Influenza A virus
Explanation:Common Vaccinations and Their Administration Schedule
Influenza, caused by three types of viruses, is a highly contagious respiratory tract infection. The influenza vaccination programme aims to protect those at risk of severe disease or complications. The World Health Organisation recommends the strains of influenza to include in the vaccine each year. Inactivated vaccines are available in the UK, containing two subtypes of influenza A and one of influenza B virus. The vaccine is recommended for children aged 6 months to 2 years in an at-risk group, those aged 18 years and over in an at-risk group, pregnant women, those aged 65 years and older, those in long-stay residential care homes, and carers.
Haemophilus influenzae type b (Hib) is a bacterium that can cause serious infections, including meningitis. Vaccination against Hib is administered in children as part of the 6-in-1 vaccine at 8, 12, and 16 weeks of age.
Clostridium tetani is a bacterium that causes tetanus, a serious disease that affects the nervous system. Vaccination against tetanus is administered in children as part of the 6-in-1 vaccine at 8, 12, and 16 weeks of age.
Hepatitis B is a virus that can cause liver disease. Vaccination against hepatitis B is administered in children as part of the 6-in-1 vaccine at 8, 12, and 16 weeks of age.
Streptococcus pneumoniae is a bacterium that can cause pneumonia, meningitis, and other serious infections. Pneumococcal vaccine is administered to children at 8, 16, and 18 weeks and to those at high risk due to long-term health conditions at 65 years of age or older (pneumococcal polysaccharide vaccine â PPV).
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This question is part of the following fields:
- Infectious Diseases
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Question 21
Correct
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A 30-year-old presents to the emergency department following an altercation. He reports being involved in a physical altercation while under the influence of alcohol at a bar. His recollection of the event is unclear, but he recalls being hit in the face and bitten on his hand. Upon examination, there is significant bruising around the left eye and a bite wound on the outer aspect of the left hand. What antibiotic should be administered for the bite?
Your Answer: Co-amoxiclav
Explanation:When it comes to treating human bites, it is recommended to use co-amoxiclav, which is also used for treating animal bites. This medication is effective in targeting the primary organisms that are commonly associated with human bites, such as Streptococcus, Staphylococcus, Eikenella, Corynebacterium, and other anaerobes. It is important to note that even if there are no visible signs of infection, antibiotics should still be prescribed.
Animal and Human Bites: Causes and Management
Animal and human bites are common injuries that can lead to infections caused by various microorganisms. Dogs and cats are the most common animals involved in bites, with Pasteurella multocida being the most commonly isolated organism. On the other hand, human bites can cause infections from both aerobic and anaerobic bacteria, including Streptococci spp., Staphylococcus aureus, Eikenella, Fusobacterium, and Prevotella.
To manage animal and human bites, it is important to cleanse the wound thoroughly. Puncture wounds should not be sutured closed unless there is a risk of cosmesis. The current recommendation for treatment is co-amoxiclav, but if the patient is allergic to penicillin, doxycycline and metronidazole are recommended. It is also important to consider the risk of viral infections such as HIV and hepatitis C in human bites.
In summary, animal and human bites can lead to infections caused by various microorganisms. Proper wound cleansing and appropriate antibiotic treatment are essential in managing these injuries. Additionally, healthcare providers should consider the risk of viral infections in human bites.
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This question is part of the following fields:
- Infectious Diseases
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Question 22
Incorrect
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Which one of the following statements regarding the vaccine used to routinely immunise adults against influenza is accurate?
Your Answer: The most common side-effect is pyrexia
Correct Answer: It is a live vaccine
Explanation:Influenza Vaccination: Who Should Get It and What to Expect
Seasonal influenza remains a significant health concern in the UK, with the flu season typically starting in November. To prevent the spread of the virus, it is recommended that individuals receive the influenza vaccine between September and early November. There are three types of influenza virus, with types A and B causing the majority of clinical disease.
Prior to 2013, flu vaccination was only offered to the elderly and at-risk groups. However, a new NHS influenza vaccination programme for children was announced in 2013. The children’s vaccine is given intranasally, with the first dose administered at 2-3 years and subsequent doses given annually. It is a live vaccine and is more effective than the injectable vaccine.
Adults and at-risk groups are also recommended to receive the influenza vaccine annually. This includes individuals over 65 years old, those with chronic respiratory or heart disease, chronic kidney or liver disease, chronic neurological disease, diabetes mellitus, immunosuppression, asplenia or splenic dysfunction, pregnant women, and those with a body mass index of 40 kg/mÂČ or higher. Health and social care staff, those living in long-stay residential care homes, and carers of the elderly or disabled person may also be eligible for the vaccine.
The influenza vaccine is an inactivated vaccine and cannot cause influenza. It is around 75% effective in adults, although this figure decreases in the elderly. It takes around 10-14 days after immunisation before antibody levels are at protective levels. The vaccine should be stored between +2 and +8ÂșC and shielded from light. Contraindications include hypersensitivity to egg protein. While a minority of patients may experience fever and malaise after receiving the vaccine, it is generally well-tolerated.
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This question is part of the following fields:
- Infectious Diseases
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Question 23
Correct
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The organism that is becoming increasingly resistant to antimicrobial agents and is responsible for a high number of hospital-acquired infections is which of the following?
Your Answer: Staphylococcus aureus
Explanation:Common Pathogens and Their Associated Infections
Hospital-acquired infections can be caused by various pathogens, including viruses, bacteria, and fungi. The most common types of infections are bloodstream infection, pneumonia, urinary tract infection, and surgical site infection. Staphylococcus aureus is a prevalent pathogen, with approximately 33% of the general population being carriers and 2% carrying the antibiotic-resistant strain MRSA. Toxoplasma gondii can cause severe disease in fetuses, newborns, and immunocompromised patients. Streptococcus pneumoniae is a leading cause of pneumonia and meningitis in children and the elderly, as well as septicaemia in HIV-infected individuals. Pneumocystis jiroveci is a rare cause of infection in the general population but can cause pneumonia in immunocompromised patients, especially those with AIDS. Listeria monocytogenes primarily affects newborns, elderly patients, and immunocompromised individuals. Understanding these common pathogens and their associated infections is crucial in preventing and treating hospital-acquired infections.
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This question is part of the following fields:
- Infectious Diseases
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Question 24
Correct
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A 30-year-old male presents to his primary care physician complaining of flu-like symptoms and myalgia. He has no significant medical history and is typically in good health. Upon conducting blood tests, the results show that he is positive for both Anti-Toxoplasmosa IgG and Anti-Toxoplasmosa IgM. What is the appropriate course of action for managing this patient at present?
Your Answer: No treatment
Explanation:Patients who are immunocompetent and have toxoplasmosis typically do not need to undergo treatment. Toxoplasmosis is a parasitic disease that is primarily found in cats and is caused by Toxoplasmosis gondii protozoa. Symptoms of the disease in humans can include malaise, myalgia, and lymphadenopathy, or it may be asymptomatic. While most healthy individuals can clear the infection, it can lead to complications such as chorioretinitis, seizures, or anemia. These complications are more likely to occur in neonates born to mothers with acute infections or in patients with compromised immune systems. The patient’s blood test results indicate that they currently have an infection, but since they are immunocompetent, treatment is not necessary at this time.
Toxoplasmosis: Symptoms, Diagnosis, and Treatment
Toxoplasmosis is a disease caused by the protozoan Toxoplasma gondii, which enters the body through the gastrointestinal tract, lungs, or broken skin. Cats are the primary carriers of the disease, but other animals like rats can also transmit it. In most cases, infected individuals do not show any symptoms. However, those who do may experience fever, malaise, and lymphadenopathy, which are similar to infectious mononucleosis. Less common symptoms include meningoencephalitis and myocarditis. Serology is the preferred diagnostic method, and treatment is usually unnecessary unless the infection is severe or the patient is immunosuppressed.
In immunocompromised patients, toxoplasmosis can cause cerebral toxoplasmosis, which accounts for about half of all cerebral lesions in HIV patients. Symptoms include constitutional symptoms, headache, confusion, and drowsiness. CT scans typically show single or multiple ring-enhancing lesions, and there may be a mass effect. Treatment involves pyrimethamine and sulphadiazine for at least six weeks. Immunocompromised patients may also develop chorioretinitis due to toxoplasmosis.
Congenital toxoplasmosis occurs when the disease is transmitted from the mother to the unborn child. It can cause a range of effects, including neurological damage, cerebral calcification, hydrocephalus, chorioretinitis, ophthalmic damage, retinopathy, and cataracts.
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This question is part of the following fields:
- Infectious Diseases
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Question 25
Incorrect
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A 32-year-old woman presents to the Emergency Department with complaints of a headache. She has been experiencing flu-like symptoms for the past three days and the headache started gradually yesterday. The headache is described as being all over and worsens when looking at bright light or bending her neck. Upon examination, her temperature is 38.2Âș, pulse is 96/min, and blood pressure is 116/78 mmHg. There is neck stiffness present, but no focal neurological signs are observed. During a closer inspection, several petechiae are noticed on her torso. The patient has been cannulated and bloods, including cultures, have been taken. What is the most appropriate next step?
Your Answer: Perform a lumbar puncture
Correct Answer: IV cefotaxime
Explanation:Immediate administration of appropriate intravenous antibiotics is crucial for this patient diagnosed with meningococcal meningitis. In light of modern PCR diagnostic techniques, there is no need to delay potentially life-saving treatment by conducting a lumbar puncture in suspected cases of meningococcal meningitis.
The investigation and management of suspected bacterial meningitis are intertwined due to the potential negative impact of delayed antibiotic treatment. Patients should be urgently transferred to the hospital, and an ABC approach should be taken initially. A lumbar puncture should be delayed in certain circumstances, and IV antibiotics should be given as a priority if there is any doubt. The bloods and CSF should be tested for various parameters, and prophylaxis should be offered to households and close contacts of patients affected with meningococcal meningitis.
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This question is part of the following fields:
- Infectious Diseases
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Question 26
Correct
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A mother brings her 8-year-old daughter to her General Practitioner, who is acutely unwell and has a high temperature, runny nose and inflamed eyes. The mother explains that her daughter has not had her vaccinations as she is worried about the long-term effects of the measles, mumps and rubella (MMR) jab.
Which of the following best reflects the current understanding of measles infection?Your Answer: It is more dangerous in overcrowded households
Explanation:Measles: Symptoms, Complications, and Prevention
Measles is a highly contagious viral infection that can lead to serious respiratory complications such as pneumonia, bronchiolitis, and bronchiectasis. While it does not cause recurrent pneumothoraces, severe infection from prolonged exposure to infected siblings in overcrowded households can be fatal.
Koplik’s spots, small red spots with bluish-white centers, are a characteristic late sign of measles infection that may appear on the mucous membranes of the mouth 1-2 days before the rash appears.
Contrary to popular belief, lifelong immunity is often established after natural infection with measles. This is also the mechanism by which the MMR vaccine prevents measles infection in later life.
Measles can also lead to corneal ulceration, especially in cases of vitamin A deficiency. High-dose oral vitamin A supplementation is recommended for all children with measles in developing countries to prevent this complication.
Overall, prevention through vaccination is the best way to avoid the serious complications of measles.
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This question is part of the following fields:
- Infectious Diseases
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Question 27
Correct
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A 21-year-old college student is brought to the emergency department by her roommates, presenting confusion and fever. She had been complaining of a severe headache and neck stiffness since yesterday. Her roommates have also noticed what appears to be bruising.
Upon examination, she appears acutely unwell, with a fever and nuchal rigidity. A widespread purpuric rash is observed, as well as general pallor and mottling.
Considering the probable diagnosis, what should be provided to her roommates?Your Answer: Oral ciprofloxacin now
Explanation:Prophylaxis for contacts of patients with meningococcal meningitis involves the use of oral ciprofloxacin or rifampicin. In this case, the patient’s symptoms indicate meningococcal meningitis, and therefore, household members and close contacts should be offered prophylaxis with ciprofloxacin as the preferred drug. Intramuscular benzylpenicillin is not appropriate for prophylaxis, but may be given to a patient with suspected meningococcal meningitis in a pre-hospital setting. Intravenous benzylpenicillin is a treatment option for the patient, not for contacts. Intravenous cefotaxime is also a treatment option for the patient, but not a suitable prophylactic antibiotic for contacts. Waiting until symptoms develop to give oral ciprofloxacin is not recommended – it should be given immediately.
The investigation and management of suspected bacterial meningitis are intertwined due to the potential negative impact of delayed antibiotic treatment. Patients should be urgently transferred to the hospital, and an ABC approach should be taken initially. A lumbar puncture should be delayed in certain circumstances, and IV antibiotics should be given as a priority if there is any doubt. The bloods and CSF should be tested for various parameters, and prophylaxis should be offered to households and close contacts of patients affected with meningococcal meningitis.
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This question is part of the following fields:
- Infectious Diseases
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Question 28
Correct
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A 38-year-old teacher presents with ongoing fatigue. During a routine blood test, abnormal liver function tests are detected, prompting a hepatitis screen. The results are as follows:
Negative for Anti-HAV IgG
Negative for HBsAg
Positive for Anti-HBs
Negative for Anti-HBc
Positive for Anti-HCV
What is the most likely interpretation of these results?Your Answer: Hepatitis C infection with previous hepatitis B vaccination
Explanation:To determine if a patient still has the hepatitis C virus, a HCV PCR test is necessary as only a small percentage of patients naturally clear the infection. Unfortunately, there is currently no vaccine available for hepatitis C.
When interpreting hepatitis B serology, the presence of surface antigen (HBsAg) typically indicates acute disease and triggers the production of anti-HBs. If HBsAg is present for more than six months, it suggests chronic disease and is infectious. Anti-HBs indicates immunity from either exposure or vaccination, while anti-HBc suggests previous or current infection. The appearance of IgM anti-HBc during acute or recent hepatitis B infection lasts for about six months. HbeAg is a marker of infectivity as it results from the breakdown of core antigen from infected liver cells.
Understanding Hepatitis C: Transmission, Complications, and Management
Hepatitis C is a viral infection that is expected to become a significant public health concern in the UK in the coming years. It is estimated that around 200,000 people in the country are chronically infected with the virus, with intravenous drug users and those who received blood transfusions prior to 1991 being at higher risk. The virus is an RNA flavivirus with an incubation period of 6-9 weeks.
Transmission of the virus can occur through needle stick injuries, vertical transmission from mother to child (especially if coexistent with HIV), and sexual intercourse (although the risk is low). There is currently no vaccine for hepatitis C. Symptoms of acute infection include a transient rise in serum aminotransferases, jaundice, fatigue, and arthralgia.
Around 15-45% of patients will clear the virus after an acute infection, while the majority (55-85%) will develop chronic hepatitis C. This can lead to complications such as rheumatological problems, cirrhosis, hepatocellular cancer, and cryoglobulinemia. Treatment for chronic infection depends on the viral genotype and aims for sustained virological response (SVR), defined as undetectable serum HCV RNA six months after the end of therapy. Interferon-based treatments are no longer recommended, with protease inhibitors such as daclatasvir and sofosbuvir or sofosbuvir and simeprevir being used instead. However, these treatments can have side effects such as haemolytic anaemia, cough, flu-like symptoms, depression, and fatigue.
In conclusion, understanding the transmission, complications, and management of hepatitis C is crucial in addressing this growing public health concern.
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This question is part of the following fields:
- Infectious Diseases
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Question 29
Correct
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A 4-year-old boy is brought to see his General Practitioner by his mother who is concerned that he has had diarrhoea for three days. He has been experiencing 2â3 loose, watery stools every day. He has also vomited twice at the onset of the illness but not since.
On examination, he is afebrile and well hydrated. His abdomen is soft and nontender. The family recently returned from a trip to Australia. While away, the patient was admitted to hospital for two days with a lower respiratory tract infection.
Which of the patientâs features is most likely to indicate the need for a stool sample for culture and sensitivity?
Select the SINGLE factor from the list below.Your Answer: The recent hospital admission
Explanation:Assessing the Need for Stool Culture in a Child with Gastroenteritis
Gastroenteritis is a common illness characterized by diarrhea, abdominal pain, and nausea. In most cases, it is caused by a viral, bacterial, or parasitic infection and is self-limiting. However, recent hospital admission or antibiotic treatment can increase the risk of Clostridium difficile toxin as the cause, making stool culture necessary. Additionally, patients who have recently traveled to certain countries or are under the age of five and attend nursery, pre-school, or school may require stool culture. If symptoms persist beyond seven days or if there is blood or mucus in the stool, stool samples should be taken. Vomiting is not a red-flag feature unless it leads to dehydration. Parents should be given safety-net advice on when to seek further medical attention if their child’s condition worsens.
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This question is part of the following fields:
- Infectious Diseases
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Question 30
Correct
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A 25-year-old woman presents to the Genitourinary Medicine Clinic with a 1-week history of a change in her vaginal discharge. She says it has a thin and white consistency with a fishy odour. There is no history of abdominal pain or urinary symptoms. She is sexually active with one regular partner and takes the combined oral contraceptive pill regularly.
On examination, her observations are within normal limits. Her abdomen is soft and nontender. Bimanual examination is unremarkable, with no adnexal tenderness elicited.
Microscopic examination reveals the presence of clue cells.
What is the most likely diagnosis?
Select the SINGLE likely diagnosis from the list below.
Select ONE option only.Your Answer: Bacterial vaginosis
Explanation:Sexually Transmitted Infections: Differentiating Bacterial Vaginosis from Other Common STIs
Bacterial vaginosis is a non-sexually transmitted infection caused by an overgrowth of Gardnerella vaginalis. It is characterized by a fishy-smelling vaginal discharge and a raised vaginal pH due to reduced lactobacilli. Clue cells on microscopy aid in diagnosis.
Chlamydia is the most contagious sexually transmitted infection, but the absence of clue cells makes it an unlikely diagnosis. Gonorrhoea, the second most common STI, presents with urethral or vaginal discharge and dysuria, but does not involve clue cells.
Syphilis, caused by Treponema pallidum, has three stages of infection, but the primary and secondary stages involve symptoms not present in this patient. Trichomoniasis, caused by Trichomonas vaginalis, presents with an offensive discharge, raised vaginal pH, and a strawberry cervix, but the presence of clue cells makes it an unlikely diagnosis.
It is important to differentiate between these common STIs and bacterial vaginosis to ensure appropriate treatment and prevent further complications.
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This question is part of the following fields:
- Infectious Diseases
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Question 31
Correct
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A 35-year-old man presents with a swollen, erythematous finger and right axillary tenderness, 24 hours after being bitten by his pet dog.
Which of the following is the best treatment?Your Answer: Co-amoxiclav
Explanation:Antibiotics for Dog Bite Infections: Recommended and Not Recommended Options
Dog bites can lead to infections caused by various micro-organisms, including anaerobic mouth flora and bacteria. Co-amoxiclav, a combination of amoxicillin and clavulanic acid, is the recommended antibiotic for dog bite-related infections, as it is effective against the most likely organisms. Fluconazole, an antifungal agent, is not indicated for such infections, as fungal micro-organisms in dogs usually cause only superficial skin rashes. Metronidazole, although effective against anaerobic bacteria, is not recommended for dog bite-related infections, except for patients allergic to penicillin. Aciclovir is not used for dog bite-related infections, as it is restricted to treating varicella-zoster and herpes zoster. Flucloxacillin, although recommended for skin infections, is not active against anaerobic bacteria and is not recommended for dog bite-related infections.
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This question is part of the following fields:
- Infectious Diseases
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Question 32
Incorrect
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A 56-year-old woman presents to the emergency department with symptoms of malaise and diarrhoea. She reports feeling shivery and achy for the past 3 days and has had 4 watery stools in the past 24 hours. The patient has a history of breast cancer and is currently undergoing chemotherapy. Her last dose of doxorubicin and cyclophosphamide was administered 10 days ago. She has no known allergies and takes no other medications. On examination, her heart rate is 103/min, respiratory rate is 20/min with saturations of 100% in room air, blood pressure is 100/79 mmHg, and temperature is 39.1ÂșC.
What is the initial management approach for this patient while awaiting the results of her blood culture?Your Answer: Vancomycin
Correct Answer: Piperacillin with tazobactam (tazocin)
Explanation:The recommended empirical antibiotic for managing neutropenic sepsis is Piperacillin with tazobactam (Tazocin). This is because the patient is displaying symptoms such as malaise, diarrhoea, flu-like aching, mild tachycardia, and a temperature >38ÂșC, and has a history of chemotherapy within the past 7-14 days. As the patient has no allergies, Tazocin should be administered until blood cultures show a specific sensitivity. Amoxicillin is not effective in treating neutropenic sepsis as it is not broad-spectrum enough. Meropenem is only indicated in patients with previous or suspected ESBL, acute leukaemia, or allogeneic stem cell transplants, and is not recommended as first-line treatment according to NICE guidelines. Teicoplanin is recommended for patients with penicillin or beta-lactam allergies and evidence of neutropenic sepsis, but should be used in combination with another non-penicillin antibiotic as per local guidelines. Vancomycin is an alternative for penicillin-allergic patients, and should be administered with gentamicin, ciprofloxacin, or amikacin depending on local guidelines and the severity of the patient’s presentation.
Neutropenic Sepsis: A Common Complication of Cancer Therapy
Neutropenic sepsis is a frequent complication of cancer therapy, particularly chemotherapy. It typically occurs within 7-14 days after chemotherapy and is characterized by a neutrophil count of less than 0.5 * 109 in patients undergoing anticancer treatment who exhibit a temperature higher than 38ÂșC or other signs or symptoms consistent with clinically significant sepsis.
To prevent neutropenic sepsis, patients who are likely to have a neutrophil count of less than 0.5 * 109 as a result of their treatment should be offered a fluoroquinolone. In the event of neutropenic sepsis, antibiotics must be initiated immediately, without waiting for the white blood cell count.
According to NICE guidelines, empirical antibiotic therapy should begin with piperacillin with tazobactam (Tazocin) immediately. While some units may add vancomycin if the patient has central venous access, NICE does not support this approach. After initial treatment, patients are typically assessed by a specialist and risk-stratified to determine if they may be able to receive outpatient treatment.
If patients remain febrile and unwell after 48 hours, an alternative antibiotic such as meropenem may be prescribed, with or without vancomycin. If patients do not respond after 4-6 days, the Christie guidelines suggest ordering investigations for fungal infections (e.g. HRCT) rather than blindly initiating antifungal therapy. In selected patients, G-CSF may be beneficial.
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This question is part of the following fields:
- Infectious Diseases
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Question 33
Correct
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A 65-year-old patient scheduled for inguinal hernia repair is discovered to have MRSA during pre-admission screening. Should any treatment be provided to him?
Your Answer: Nasal mupirocin + chlorhexidine for the skin
Explanation:Understanding MRSA and Screening for Infection
Methicillin-resistant Staphylococcus aureus (MRSA) is a type of bacteria that can cause serious infections and is particularly dangerous in hospital settings. To prevent the spread of MRSA, certain patients should be screened for the infection, including those awaiting elective admissions and all emergency admissions starting in 2011. Screening involves taking a nasal swab and checking for skin lesions or wounds. If a patient is found to be a carrier of MRSA, treatment involves using antibiotics such as vancomycin, teicoplanin, or linezolid. However, some strains may develop resistance to these antibiotics, so newer options like linezolid, quinupristin/dalfopristin combinations, and tigecycline should be reserved for resistant cases. It is important to suppress MRSA from carriers to prevent the spread of infection. This can be done through the use of mupirocin and chlorhexidine gluconate. By understanding MRSA and screening for infection, healthcare providers can take steps to prevent the spread of this dangerous bacteria.
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This question is part of the following fields:
- Infectious Diseases
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Question 34
Correct
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A 25-year-old man visits his General Practitioner with a complaint of a sore throat that has been bothering him for the past three weeks. He reports feeling significantly fatigued, which is affecting his academic performance. On examination, he appears healthy and has tender cervical lymphadenopathy; his tonsils are enlarged but no exudate is present, and he has tender splenomegaly.
Which of the following investigation findings is most likely to be associated with this condition?
Select the SINGLE most appropriate result from the list below.Your Answer: Raised liver transaminases (aspartate transaminase and alanine aminotransferase)
Explanation:The patient has raised liver transaminases, thrombocytosis, neutrophilia, raised antistreptolysin titres, and a reduced estimated glomerular filtration rate (eGFR). The most probable diagnosis is glandular fever/infectious mononucleosis caused by the Epstein-Barr virus (EBV). This infection is common in adolescents and presents with a prolonged sore throat, lethargy, and flu-like symptoms. Splenomegaly or hepatosplenomegaly, along with lymphadenopathy, are often observed. Liver function tests, especially the transaminases, are commonly elevated during active infection. Thrombocytopenia is commonly associated with glandular fever due to splenic involvement. Neutrophilia is less likely in this case than lymphocytosis, which is common with glandular fever. Antistreptolysin titres rise after a streptococcal infection, but glandular fever is a more likely diagnosis than streptococcal infection. Reduced eGFR associated with a sore throat should raise suspicion of dehydration or glomerulonephritis caused by a streptococcal infection, but neither of these diagnoses is as likely as glandular fever. The diagnostic investigation of choice for glandular fever is the Monospot test, which tests for heterophile antibodies to EBV.
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This question is part of the following fields:
- Infectious Diseases
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Question 35
Correct
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A 15-year-old girl presents to her GP with her father, reporting a rash and fatigue. She has been feeling generally unwell for the past week since returning from a trip to Europe. During the examination, a circular rash is observed, with a more pronounced appearance in the center and edges. The rash is warm and red but does not cause any pain. What possible illnesses should be considered in this patient?
Your Answer: Lyme disease
Explanation:Lyme disease is caused by the bacteria Borrelia, which is transmitted to humans through tick bites. The most common symptom of Lyme disease is a characteristic rash that appears at the site of the tick bite. Other symptoms of the disease are general and can include fever, headache, fatigue, and even paralysis.
Understanding Lyme Disease
Lyme disease is a bacterial infection caused by Borrelia burgdorferi and is transmitted through tick bites. The early symptoms of Lyme disease include erythema migrans, a characteristic bulls-eye rash that appears at the site of the tick bite. This rash is painless, slowly increases in size, and can be more than 5 cm in diameter. Other early symptoms include headache, lethargy, fever, and joint pain.
If erythema migrans is present, Lyme disease can be diagnosed clinically, and antibiotics should be started immediately. The first-line test for Lyme disease is an enzyme-linked immunosorbent assay (ELISA) to detect antibodies to Borrelia burgdorferi. If the ELISA is negative but Lyme disease is still suspected, it should be repeated 4-6 weeks later. If Lyme disease is suspected in patients who have had symptoms for 12 weeks or more, an immunoblot test should be done.
Tick bites can cause significant anxiety, but routine antibiotic treatment is not recommended by NICE. If the tick is still present, it should be removed using fine-tipped tweezers, and the area should be washed. In cases of suspected or confirmed Lyme disease, doxycycline is the preferred treatment for early disease, while ceftriaxone is used for disseminated disease. A Jarisch-Herxheimer reaction may occur after initiating therapy, which can cause fever, rash, and tachycardia.
In summary, Lyme disease is a bacterial infection transmitted through tick bites. Early symptoms include erythema migrans, headache, lethargy, fever, and joint pain. Diagnosis is made through clinical presentation and ELISA testing, and treatment involves antibiotics. Tick bites do not require routine antibiotic treatment, and ticks should be removed using fine-tipped tweezers.
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This question is part of the following fields:
- Infectious Diseases
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Question 36
Correct
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A previously healthy 27-year-old man presents with abdominal discomfort and shortness of breath. He has been experiencing a dry cough for the past two weeks. He works as a full-time accountant, does not smoke, and drinks approximately 15 units of alcohol per week. He recently went on a trip to Amsterdam with some friends. He has also noticed a widespread skin rash with pink rings and pale centers. Upon admission, his blood work shows low sodium levels, normal potassium levels, elevated urea levels, and high creatinine levels. His chest x-ray reveals diffuse reticular infiltrates and a small pleural effusion on the right side. What is the most likely organism responsible for his symptoms?
Your Answer: Mycoplasma pneumoniae
Explanation:Typical presentation of mycoplasma pneumonia includes flu-like symptoms that progressively worsen and a dry cough. During examination, the patient may exhibit erythema multiforme, indicating the presence of the infection. This type of pneumonia is commonly acquired within the community. Although Streptococcus pneumoniae is also a possible cause, it is not the focus of this particular case.
Mycoplasma pneumoniae: A Cause of Atypical Pneumonia
Mycoplasma pneumoniae is a type of bacteria that causes atypical pneumonia, which is more common in younger patients. This disease is associated with various complications such as erythema multiforme and cold autoimmune haemolytic anaemia. Epidemics of Mycoplasma pneumoniae typically occur every four years. It is important to recognize atypical pneumonia because it may not respond to penicillins or cephalosporins due to the bacteria lacking a peptidoglycan cell wall.
The disease usually has a gradual onset and is preceded by flu-like symptoms, followed by a dry cough. X-rays may show bilateral consolidation. Complications may include cold agglutinins, erythema multiforme, erythema nodosum, meningoencephalitis, Guillain-Barre syndrome, bullous myringitis, pericarditis/myocarditis, and gastrointestinal and renal problems.
Diagnosis is generally made through Mycoplasma serology and a positive cold agglutination test. Management involves the use of doxycycline or a macrolide such as erythromycin or clarithromycin.
In comparison to Legionella pneumonia, which is caused by a different type of bacteria, Mycoplasma pneumoniae has a more gradual onset and is associated with different complications. It is important to differentiate between the two types of pneumonia to ensure appropriate treatment.
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This question is part of the following fields:
- Infectious Diseases
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Question 37
Correct
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A human immunodeficiency virus (HIV)-positive teenager who recently returned from the tropics presents with severe diarrhoea (up to 30 times per day).
Which of the following is the most likely cause?
Your Answer: Cryptosporidium species
Explanation:Differential diagnosis of diarrhoea in an HIV-positive patient
Human cryptosporidiosis, caused by Cryptosporidium species, is a common opportunistic infection in HIV/AIDS patients, leading to prolonged and severe diarrhoea. Escherichia coli can cause urinary and enteric infections, but an alternative aetiology is more likely in this case. Staphylococcus aureus is a commensal bacterium that can cause various infections, but it is not suggested by this clinical scenario. Entamoeba histolytica, which causes amoebiasis, is more prevalent in developing countries and may cause dysentery and invasive extra-intestinal manifestations, but an alternative aetiology is more likely in this case. Salmonella species can be transmitted orally via contaminated food or beverages and may cause non-typhoidal enterocolitis, focal disease, or typhoid fever, but an alternative aetiology is more likely in this case, given the severity of diarrhoea and the patient’s HIV-positive status. Therefore, a thorough differential diagnosis is necessary to identify the underlying cause of diarrhoea in this patient and provide appropriate treatment.
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This question is part of the following fields:
- Infectious Diseases
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Question 38
Correct
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A human immunodeficiency virus-1 (HIV-1)-positive woman develops multiple raised purple lesions on her legs. Her CD4 count is 96 cells/mm3 (normal range: > 600 mm3) and her viral load measures greater than 500 000 copies/ml.
Which one of the following is the most likely diagnosis?Your Answer: Kaposiâs sarcoma
Explanation:Differential Diagnosis for a Raised Nodular Lesion: Common Skin Conditions in HIV-1 Patients
Kaposiâs sarcoma is a prevalent tumour in HIV-1-positive individuals and a leading cause of death in these patients. It is an AIDS-defining illness in 15% of patients and commonly occurs with a CD4 count of fewer than 200 cells/mm3. Other common tumours in HIV-1 include non-Hodgkinâs lymphoma, Hodgkinâs lymphoma, and those caused by human papillomavirus. Basal cell carcinoma, the most common non-melanoma skin cancer, typically presents with a single, shiny, pearlised nodule and may ulcerate, but does not match the description in this scenario. Cryoglobulinaemia, a condition associated with hepatitis C infection, causes a vasculitic rash and does not match this scenario’s description. Fixed drug eruption describes the development of one or more annular or oval erythematous plaques resulting from systemic exposure to a drug and does not tend to cause raised nodular lesions. Melanoma is typically black/darkly pigmented and usually a single lesion, therefore it does not match the description in this scenario.
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This question is part of the following fields:
- Infectious Diseases
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Question 39
Correct
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When visiting a 60-year-old patient at home to do a wound dressing, the District Nurse wants to confirm if the patient has received complete tetanus vaccination. What is the number of tetanus vaccine doses required for life-long protection?
Your Answer: 5
Explanation:Tetanus Vaccination and Management of Wounds
The tetanus vaccine is a purified toxin that is given as part of a combined vaccine. In the UK, it is given as part of the routine immunisation schedule at 2, 3, and 4 months, 3-5 years, and 13-18 years, providing a total of 5 doses for long-term protection against tetanus.
When managing wounds, the first step is to classify them as clean, tetanus-prone, or high-risk tetanus-prone. Clean wounds are less than 6 hours old and have negligible tissue damage, while tetanus-prone wounds include puncture-type injuries acquired in a contaminated environment or wounds containing foreign bodies. High-risk tetanus-prone wounds include wounds or burns with systemic sepsis, certain animal bites and scratches, heavy contamination with material likely to contain tetanus spores, wounds or burns with extensive devitalised tissue, and wounds or burns that require surgical intervention.
If the patient has had a full course of tetanus vaccines with the last dose less than 10 years ago, no vaccine or tetanus immunoglobulin is required regardless of the wound severity. If the patient has had a full course of tetanus vaccines with the last dose more than 10 years ago, a reinforcing dose of vaccine is required for tetanus-prone wounds, and a reinforcing dose of vaccine plus tetanus immunoglobulin is required for high-risk wounds. If the vaccination history is incomplete or unknown, a reinforcing dose of vaccine is required regardless of the wound severity, and a reinforcing dose of vaccine plus tetanus immunoglobulin is required for tetanus-prone and high-risk wounds.
Overall, proper vaccination and wound management are crucial in preventing tetanus infection.
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This question is part of the following fields:
- Infectious Diseases
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Question 40
Correct
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A 20-year-old male returns from Ghana and presents with a fever of 40°C. He reports having bloody stools prior to this. Upon examination, he displays abdominal distension, hepatosplenomegaly, and rose spots on his abdomen. Unfortunately, he passes away before receiving empirical treatment due to bowel perforation, leading to severe sepsis. What is the causative organism responsible for this type of pathology?
Your Answer: Salmonella typhi
Explanation:Infections caused by Salmonella typhi can result in the development of rose spots on the abdomen. While these spots are also associated with C.psittaci infections, they are more commonly seen in cases of typhoid fever. Giardiasis typically does not cause such severe and sudden symptoms, while syphilis is characterized by the presence of painless chancres. Staphylococcus aureus infections, on the other hand, typically result in rapid onset of symptoms, including violent vomiting.
Enteric fever, also known as typhoid or paratyphoid, is caused by Salmonella typhi and Salmonella paratyphi respectively. These bacteria are not normally found in the gut and are transmitted through contaminated food and water or the faecal-oral route. The symptoms of enteric fever include headache, fever, and joint pain, as well as abdominal pain and distension. Constipation is more common in typhoid than diarrhoea, and rose spots may appear on the trunk in some patients. Complications can include osteomyelitis, gastrointestinal bleeding or perforation, meningitis, cholecystitis, and chronic carriage. Chronic carriage is more likely in adult females and occurs in approximately 1% of cases.
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This question is part of the following fields:
- Infectious Diseases
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Question 41
Correct
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Which one of the following is not a notifiable disease in the United Kingdom?
Your Answer: HIV
Explanation:Notifying authorities about HIV is not required.
Notifiable Diseases in the UK
In the UK, certain diseases are considered notifiable, meaning that the Local Health Protection Team must be notified if a case is suspected or confirmed. The Proper Officer at the team will then inform the Health Protection Agency on a weekly basis. Notifiable diseases include acute encephalitis, acute infectious hepatitis, acute meningitis, acute poliomyelitis, anthrax, botulism, brucellosis, cholera, COVID-19, diphtheria, enteric fever, food poisoning, haemolytic uraemic syndrome, infectious bloody diarrhoea, invasive group A streptococcal disease, legionnaires disease, leprosy, malaria, measles, meningococcal septicaemia, mumps, plague, rabies, rubella, severe acute respiratory syndrome, scarlet fever, smallpox, tetanus, tuberculosis, typhus, viral haemorrhagic fever, whooping cough, and yellow fever.
It is important to note that HIV is not a notifiable disease in the UK, and in April 2010, dysentery, ophthalmia neonatorum, leptospirosis, and relapsing fever were removed from the list of notifiable diseases. The purpose of notifiable diseases is to monitor and control the spread of infectious diseases in the population. By requiring healthcare professionals to report cases, public health officials can track outbreaks and take appropriate measures to prevent further transmission.
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This question is part of the following fields:
- Infectious Diseases
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Question 42
Correct
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Sarah is a 44-year-old hairdresser who contacts her GP due to a 2-day history of cough and fever. Her Covid-19 test is negative and she does not sound breathless on the phone. Sarah has been taking paracetamol regularly but despite this, she is still feeling feverish; she has recorded her temperature as 37.8ÂșC. She has a past medical history of eczema, gilbert's syndrome and adrenal insufficiency. She takes hydrocortisone 15 mg in the morning and 10mg at lunchtime, and also takes fludrocortisone 200 micrograms once a day.
What is the most appropriate management plan for Sarah?Your Answer: Double the dose of his hydrocortisone
Explanation:To manage an Addison’s patient with an intercurrent illness, it is recommended to double the dose of their glucocorticoids, specifically hydrocortisone, while keeping the fludrocortisone dose the same. This is because the patient’s fever >37.5 indicates a moderate intercurrent illness. Continuing paracetamol regularly is not the main priority in this situation. Advising the patient to call 999 for admission is unnecessary unless there are severe symptoms such as vomiting or persistent diarrhea. Doubling the dose of fludrocortisone is not recommended as it is a mineralocorticoid with weak glucocorticoid activity, and increasing the glucocorticoid is necessary to mimic a stress response.
Addison’s disease is a condition that requires patients to undergo both glucocorticoid and mineralocorticoid replacement therapy. This treatment usually involves taking a combination of hydrocortisone and fludrocortisone. Hydrocortisone is typically given in 2 or 3 divided doses, with patients requiring 20-30 mg per day, mostly in the first half of the day. Patient education is crucial, and it is essential to emphasize the importance of not missing glucocorticoid doses. Additionally, patients should consider wearing MedicAlert bracelets and steroid cards, and they should be provided with hydrocortisone for injection with needles and syringes to treat an adrenal crisis.
During an intercurrent illness, it is crucial to manage the glucocorticoid dose properly. In simple terms, the glucocorticoid dose should be doubled, while the fludrocortisone dose should remain the same. The Addison’s Clinical Advisory Panel has produced guidelines that detail specific scenarios, and patients should refer to these guidelines for more information. It is essential to discuss how to adjust the glucocorticoid dose during an intercurrent illness with a healthcare professional. Proper management of Addison’s disease is crucial to ensure that patients can lead healthy and fulfilling lives.
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This question is part of the following fields:
- Infectious Diseases
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Question 43
Correct
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An 18-year-old woman who is sexually active presents to her General Practitioner (GP) complaining of dysuria and abdominal pain. A urine dipstick test is positive for leukocytes and a pregnancy test is negative. The GP prescribes a course of trimethoprim, but the patient returns one week later with persistent symptoms. Despite negative results from a high vaginal swab and urine culture taken during the first visit, what is the most likely cause of her symptoms?
Your Answer: Chlamydia trachomatis
Explanation:Differential Diagnosis of a Female Patient with Dysuria and Abdominal Pain
A female patient presents with dysuria and abdominal pain, but a negative urine culture and lack of response to trimethoprim suggest an alternative diagnosis to urinary tract infection. Here are some possible differential diagnoses:
Chlamydia trachomatis: This sexually transmitted micro-organism can cause cervicitis, salpingitis, endometritis, and urethritis. Many carriers are asymptomatic, but nucleic acid amplification can diagnose the infection from a urine sample, endocervical or vulvovaginal swab.
Trichomonas vaginalis: This protozoan causes trichomoniasis, a sexually transmitted infection that commonly presents with abnormal vaginal discharge, odour, itching, burning, soreness, and dyspareunia. Abdominal pain and dysuria are not typical symptoms.
Escherichia coli: This bacterium is the most common cause of uncomplicated UTIs, but negative urine cultures and trimethoprim resistance suggest an alternative diagnosis.
Candida albicans: This fungus can cause vulvovaginal thrush, which may present with dysuria and vulval pruritus, but not abdominal pain. A high vaginal swab can diagnose the infection.
Bacterial vaginosis: This overgrowth of bacteria in the vagina affects vaginal pH and causes a fishy smelling discharge, but not abdominal pain or dysuria. A high vaginal swab can diagnose the condition.
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This question is part of the following fields:
- Infectious Diseases
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Question 44
Correct
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A 65-year-old woman arrives at the Emergency Department complaining of breathlessness and a dry cough that has persisted for three weeks. She is a non-smoker and consumes 10 units of alcohol per week. The patient has a target rash on both of her lower limbs, and her chest x-ray reveals reticulonodular shadowing on the left lung. The medical team diagnoses her with bacterial pneumonia. What is the probable causative agent responsible for her symptoms?
Your Answer: Mycoplasma pneumoniae
Explanation:Based on the dry cough, symmetrical target-shaped rash with a central blister (erythema multiforme), and radiological findings, it is likely that the woman has Mycoplasma. While pneumococcal pneumonia is the most common type of pneumonia in the community, it would typically present with lobar consolidation on an x-ray and a productive cough, rather than a dry one. Klebsiella pneumonia is more common in alcoholics, but the woman’s drinking habits, while exceeding the recommended limit for women (14 units per week), are not severe enough to increase her risk of Klebsiella. Additionally, Klebsiella pneumonia typically causes a cavitating pneumonia in the upper lobes.
Mycoplasma pneumoniae: A Cause of Atypical Pneumonia
Mycoplasma pneumoniae is a type of bacteria that causes atypical pneumonia, which is more common in younger patients. This disease is associated with various complications such as erythema multiforme and cold autoimmune haemolytic anaemia. Epidemics of Mycoplasma pneumoniae typically occur every four years. It is important to recognize atypical pneumonia because it may not respond to penicillins or cephalosporins due to the bacteria lacking a peptidoglycan cell wall.
The disease usually has a gradual onset and is preceded by flu-like symptoms, followed by a dry cough. X-rays may show bilateral consolidation. Complications may include cold agglutinins, erythema multiforme, erythema nodosum, meningoencephalitis, Guillain-Barre syndrome, bullous myringitis, pericarditis/myocarditis, and gastrointestinal and renal problems.
Diagnosis is generally made through Mycoplasma serology and a positive cold agglutination test. Management involves the use of doxycycline or a macrolide such as erythromycin or clarithromycin.
In comparison to Legionella pneumonia, which is caused by a different type of bacteria, Mycoplasma pneumoniae has a more gradual onset and is associated with different complications. It is important to differentiate between the two types of pneumonia to ensure appropriate treatment.
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This question is part of the following fields:
- Infectious Diseases
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Question 45
Correct
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A 35-year-old woman presents to the emergency department with a cat bite on her hand while house-sitting for her neighbor. She complains of mild pain and swelling around the bite but denies having a fever. Upon examination, there is a small puncture wound on the palm of her left hand with mild erythema around it, but no visible purulent discharge. What is the best course of treatment for this patient?
Your Answer: Co-amoxiclav
Explanation:When a patient suffers an animal bite, it is likely that the wound will be infected with multiple types of bacteria. The most frequently identified bacteria in cultures from animal bites is Pasteurella multocida. To prevent infection, it is important to clean the wound thoroughly and provide the patient with tetanus and antibiotics. According to NICE guidelines, co-amoxiclav is the preferred antibiotic as it effectively targets the bacteria commonly found in animal bites.
Animal and Human Bites: Causes and Management
Animal and human bites are common injuries that can lead to infections caused by various microorganisms. Dogs and cats are the most common animals involved in bites, with Pasteurella multocida being the most commonly isolated organism. On the other hand, human bites can cause infections from both aerobic and anaerobic bacteria, including Streptococci spp., Staphylococcus aureus, Eikenella, Fusobacterium, and Prevotella.
To manage animal and human bites, it is important to cleanse the wound thoroughly. Puncture wounds should not be sutured closed unless there is a risk of cosmesis. The current recommendation for treatment is co-amoxiclav, but if the patient is allergic to penicillin, doxycycline and metronidazole are recommended. It is also important to consider the risk of viral infections such as HIV and hepatitis C in human bites.
In summary, animal and human bites can lead to infections caused by various microorganisms. Proper wound cleansing and appropriate antibiotic treatment are essential in managing these injuries. Additionally, healthcare providers should consider the risk of viral infections in human bites.
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This question is part of the following fields:
- Infectious Diseases
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Question 46
Incorrect
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A 65-year-old woman presents to the Emergency Department with a cough, fever, diarrhoea and myalgia. The cough is non-productive and has been getting gradually worse since she returned from holiday in Italy one week ago. Her daughter is concerned because over the past 24 hours she has become more drowsy and febrile. She is normally fit and well but drinks around 15 units of alcohol per week.
On examination, pulse is 80/min, blood pressure 110/70 mmHg, oxygen saturations are 95% on room air and temperature is 38.2ÂșC. Bilateral coarse crackles are heard in the chest.
Initial blood tests show the following:
Hb 13.8 g/dl
Platelets 300 * 109/l
WBC 14.5 * 109/l
Na+ 132 mmol/l
K+ 4.1 mmol/l
Urea 8.9 mmol/l
Creatinine 89 ”mol/l
Bilirubin 11 ”mol/l
ALP 35 u/l
ALT 62 u/l
A chest x-ray shows patchy consolidation in the right lower zone with an associated pleural effusion.
What is the most likely causative organism?Your Answer: Mycoplasma pneumoniae
Correct Answer: Legionella pneumophila
Explanation:Legionella is often characterized by symptoms resembling the flu, such as a dry cough, confusion, and a slower than normal heart rate. Additionally, hyponatremia may be detected through blood tests. A history of recent travel abroad and the presence of pleural effusion are also indicative of Legionella.
Legionnaire’s Disease: Symptoms, Diagnosis, and Management
Legionnaire’s disease is a type of pneumonia caused by the Legionella pneumophilia bacterium, which is commonly found in water tanks. It is not transmitted from person to person. Symptoms of the disease include flu-like symptoms such as fever, dry cough, confusion, and lymphopaenia. Other features include relative bradycardia, hyponatraemia, and deranged liver function tests. Pleural effusion is seen in around 30% of patients.
Diagnosis of Legionnaire’s disease can be done through a urinary antigen test. Treatment involves the use of erythromycin or clarithromycin. Chest x-ray features of the disease are non-specific but may include patchy consolidation with a mid-to-lower zone predominance.
Compared to Mycoplasma pneumonia, Legionnaire’s disease has distinct differences in symptoms and diagnostic methods. It is important to be aware of the potential for Legionnaire’s disease in cases where water tanks or air-conditioning systems may be involved, as early diagnosis and treatment can lead to better outcomes.
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This question is part of the following fields:
- Infectious Diseases
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Question 47
Correct
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A 35-year-old woman presents with a 7-day history of mucopurulent anal discharge, bloody stool and pain during defecation. She denies any recent travel and has not experienced any vomiting episodes.
Which of the following is the most probable diagnosis?
Your Answer: Gonorrhoea
Explanation:Sexually Transmitted Infections: Differential Diagnosis
Sexually transmitted infections (STIs) are a common cause of morbidity worldwide. When evaluating a patient with symptoms suggestive of an STI, it is important to consider a broad differential diagnosis. Here are some common STIs and their clinical presentations:
Gonorrhoea: This is a purulent infection of the mucous membranes caused by Neisseria gonorrhoeae. In men, symptoms include urethritis, acute epididymitis, and rectal infection. A diagnosis can be made by identifying typical Gram-negative intracellular diplococci after a Gram stain.
Crohn’s disease: This is an inflammatory bowel disease that presents with prolonged diarrhea, abdominal pain, anorexia, and weight loss. It is not consistent with a typical STI presentation.
Candidiasis: This is a fungal infection caused by yeasts from the genus Candida. It is associated with balanitis, presenting with penile pruritus and whitish patches on the penis.
Salmonella infection: This is often transmitted orally via contaminated food or beverages. Symptoms include a severe non-specific febrile illness, which can be confused with typhoid fever. There is nothing in this clinical scenario to suggest Salmonella infection.
Chancroid: This is a bacterial STI caused by Haemophilus ducreyi. It is characterised by painful necrotising genital ulcers and inguinal lymphadenopathy.
In summary, a thorough differential diagnosis is important when evaluating patients with symptoms suggestive of an STI.
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This question is part of the following fields:
- Infectious Diseases
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Question 48
Correct
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A 28-year-old woman returns from a holiday in Kenya with symptoms of foul-smelling loose stools, abdominal cramps and frequent flatulence. She has had the symptoms for five days when she presents to her General Practitioner for advice. A diagnosis of giardiasis is suspected.
What would be the most useful investigation to request for this patient?Your Answer: Send stool culture for microscopy and culture (MC+S)
Explanation:Diagnostic Tests for Giardiasis: Which Ones Are Necessary?
Giardiasis is a common parasitic infection that can cause gastrointestinal symptoms such as diarrhoea, abdominal pain, and bloating. If a patient presents with these symptoms and has a history of recent foreign travel, giardiasis should be considered as a possible cause. Here are some diagnostic tests that may be ordered to confirm the diagnosis:
Stool Culture for Microscopy and Culture (MC+S)
This test is specific for detecting giardia and other potential parasitic causes of gastrointestinal symptoms. It involves sending three stool specimens 2-3 days apart to a laboratory for analysis.Colonoscopy
A colonoscopy is not necessary to diagnose giardiasis, as the patient’s symptoms and travel history are usually sufficient to suggest the diagnosis. A stool culture is a more appropriate test.Duodenal Biopsy
A duodenal biopsy is not necessary to diagnose giardiasis, as it is an invasive test that is typically reserved for investigating malabsorption, iron-deficiency anaemia, or neoplasia.Full Blood Count
A full blood count is not useful for diagnosing giardiasis, as it typically does not cause peripheral leukocytosis or eosinophilia.In summary, a stool culture for MC+S is the most appropriate test for diagnosing giardiasis in a patient with gastrointestinal symptoms and a history of recent foreign travel. Other tests, such as colonoscopy, duodenal biopsy, and full blood count, are not necessary for making the diagnosis.
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This question is part of the following fields:
- Infectious Diseases
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Question 49
Correct
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A 20-year-old woman presents with complaints of malaise, tiredness, headache and abdominal discomfort over the past 3â4 days. She was prescribed amoxicillin two days ago and has developed a rash. She has lymphadenopathy and exudative tonsillitis. Her white cell count shows abnormal lymphocytosis.
What is the most probable diagnosis?Your Answer: Infectious mononucleosis
Explanation:Common Viral Infections: Symptoms and Characteristics
Infectious mononucleosis, also known as the kissing disease, is caused by the Epstein-Barr virus and is characterized by fever, pharyngitis, and adenopathy. It is primarily transmitted through intimate contact with body secretions, particularly oropharyngeal secretions. Pharyngitis is caused by the proliferation of infected B lymphocytes in the lymphatic tissue of the oropharynx. It is most common in young adults and can be mistaken for streptococcal pharyngitis.
German measles, or rubella, is a communicable exanthematous disease that is generally benign. However, pregnant women who contract the disease in the early weeks of gestation can experience teratogenic effects. The exanthema of rubella consists of a rose-pink maculopapular rash that starts on the face and neck and spreads to the trunk and extremities within 24 hours. It typically fades by the end of the third day.
Chickenpox is a childhood illness caused by the varicella-zoster virus. It is characterized by a vesicular exanthem and is typically self-limited and mild.
Herpes simplex viruses are host-adapted pathogens that cause a wide variety of disease states. HSV-1 is associated with orofacial disease, while HSV-2 is associated with genital disease. Oropharyngeal HSV-1 infection causes pharyngitis and tonsillitis more often than gingivostomatitis. Herpes labialis, or cold sores, is the most common manifestation of recurrent HSV-1 infection.
Cytomegalovirus (CMV) infection is prevalent in developed countries, with at least 60% of the population having been exposed. It typically causes an asymptomatic infection or produces mild flu-like symptoms, with few clinical findings on physical examination. High-risk groups, such as fetuses whose mothers become infected during pregnancy or people with HIV, are more susceptible to severe complications.
Overview of Common Viral Infections and Their Characteristics
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This question is part of the following fields:
- Infectious Diseases
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Question 50
Correct
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Which one of the following is true regarding anti-tuberculous therapy?
Your Answer: Visual acuity should be checked before starting ethambutol
Explanation:Rifampicin has a strong ability to induce liver enzymes. During the initial two months of treatment, Pyrazinamide should be administered, but it may cause hepatitis and gout as side effects. Isoniazid may cause peripheral neuropathy as a side effect.
Managing Tuberculosis: Treatment and Complications
Tuberculosis is a serious infectious disease that requires prompt and effective treatment. The standard therapy for active tuberculosis involves an initial phase of two months, during which patients are given a combination of four drugs: rifampicin, isoniazid, pyrazinamide, and ethambutol. The continuation phase lasts for four months and involves the use of rifampicin and isoniazid. Patients with latent tuberculosis are typically treated with a combination of isoniazid and rifampicin for three or six months, depending on the severity of the infection.
In some cases, patients may require prolonged treatment, particularly if they have meningeal tuberculosis. Steroids may be added to the treatment regimen in these cases. Directly observed therapy may also be necessary for certain groups, such as homeless individuals, prisoners, and patients who are likely to have poor concordance.
While tuberculosis treatment is generally effective, there are some potential complications to be aware of. Immune reconstitution disease can occur several weeks after starting treatment and may present with enlarging lymph nodes. Drug adverse effects are also possible, with rifampicin being a potent liver enzyme inducer and isoniazid causing peripheral neuropathy. Pyrazinamide can cause hyperuricaemia and ethambutol may lead to optic neuritis, so it is important to monitor patients closely for any signs of adverse effects. Overall, with proper management and monitoring, tuberculosis can be successfully treated.
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This question is part of the following fields:
- Infectious Diseases
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Question 51
Incorrect
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A 67-year-old man is brought to the emergency department by his daughter who is worried about his confusion after a recent chest infection. She mentions that he did not get better even after taking amoxicillin. During the examination, crackles are heard on the left side of his chest and his vital signs show a respiratory rate of 28/min, blood pressure of 90/60 mmHg, and heart rate of 110/min.
What would be the suitable fluid therapy to administer?Your Answer: 10 ml/kg over 1 hour
Correct Answer: 500ml stat
Explanation:This individual displays several indicators of red flag sepsis, such as confusion, hypotension, and elevated respiratory rate. It is imperative to initiate the sepsis 6 protocol.
According to the NICE guidelines for sepsis, when administering intravenous fluid resuscitation to patients aged 16 and above, it is recommended to use crystalloids containing sodium levels between 130-154 mmol/litre, with a 500 ml bolus administered in less than 15 minutes.Understanding Sepsis: Classification and Management
Sepsis is a life-threatening condition caused by a dysregulated host response to an infection. In recent years, the classification of sepsis has changed, with the old category of severe sepsis no longer in use. Instead, the Surviving Sepsis Guidelines now recognize sepsis as life-threatening organ dysfunction caused by a dysregulated host response to infection, and septic shock as a more severe form of sepsis. The term ‘systemic inflammatory response syndrome (SIRS)’ has also fallen out of favor.
To manage sepsis, it is important to identify and treat the underlying cause of the infection and support the patient regardless of the cause or severity. However, if any red flags are present, the ‘sepsis six’ should be started immediately. This includes administering oxygen, taking blood cultures, giving broad-spectrum antibiotics, giving intravenous fluid challenges, measuring serum lactate, and measuring accurate hourly urine output.
NICE released its own guidelines in 2016, which focus on the risk stratification and management of patients with suspected sepsis. For risk stratification, NICE recommends using red flag and amber flag criteria. If any red flags are present, the sepsis six should be started immediately. If any amber flags are present, the patient should be closely monitored and managed accordingly.
To help identify and categorize patients, the Sequential (Sepsis-Related) Organ Failure Assessment Score (SOFA) is increasingly used. The score grades abnormality by organ system and accounts for clinical interventions. A SOFA score of 2 or more reflects an overall mortality risk of approximately 10% in a general hospital population with suspected infection. Even patients presenting with modest dysfunction can deteriorate further, emphasizing the seriousness of this condition and the need for prompt and appropriate intervention.
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This question is part of the following fields:
- Infectious Diseases
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Question 52
Correct
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Which of the following is a live attenuated vaccine?
Your Answer: Mumps
Explanation:Live attenuated vaccines include BCG, MMR, oral polio, yellow fever, and oral typhoid.
Types of Vaccines and Their Characteristics
Vaccines are essential in preventing the spread of infectious diseases. However, it is crucial to understand the different types of vaccines and their characteristics to ensure their safety and effectiveness. Live attenuated vaccines, such as BCG, MMR, and oral polio, may pose a risk to immunocompromised patients. In contrast, inactivated preparations, including rabies and hepatitis A, are safe for everyone. Toxoid vaccines, such as tetanus, diphtheria, and pertussis, use inactivated toxins to generate an immune response. Subunit and conjugate vaccines, such as pneumococcus, haemophilus, meningococcus, hepatitis B, and human papillomavirus, use only part of the pathogen or link bacterial polysaccharide outer coats to proteins to make them more immunogenic. Influenza vaccines come in different types, including whole inactivated virus, split virion, and sub-unit. Cholera vaccine contains inactivated strains of Vibrio cholerae and recombinant B-subunit of the cholera toxin. Hepatitis B vaccine contains HBsAg adsorbed onto aluminium hydroxide adjuvant and is prepared from yeast cells using recombinant DNA technology. Understanding the different types of vaccines and their characteristics is crucial in making informed decisions about vaccination.
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This question is part of the following fields:
- Infectious Diseases
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Question 53
Correct
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As a foundation doctor in the emergency decisions unit, you assess a 28-year-old intravenous drug user who complains of pyrexia and malaise. Upon examination, the patient appears cachectic, pale, and is coughing. A soft murmur is detected, and mild erythematous macular lesions are observed on both palms. Although the patient is experiencing general aches, there is no specific tenderness reported. Can you identify the probable diagnosis and explain the significance of the lesions?
Your Answer: Janeway lesions
Explanation:Janeway lesions are painless, red, and bloody lesions that appear on the palms and soles. They are typically associated with infective endocarditis.
Based on the patient’s history of intravenous drug use, fever, and heart murmur, it is likely that he has infective endocarditis. Both janeway lesions (caused by septic emboli) and osler nodes (caused by immune complex deposition) can be present in endocarditis. However, in this case, the lesions are more likely to be janeway lesions as they are not painful.
Roth spots are retinal hemorrhages that can also be seen in endocarditis, but they would be detected during a fundoscopy exam.
If the patient had meningitis, the rash would not be limited to the palms and would not disappear when pressed.
Aetiology of Infective Endocarditis
Infective endocarditis is a condition that affects patients with previously normal valves, rheumatic valve disease, prosthetic valves, congenital heart defects, intravenous drug users, and those who have recently undergone piercings. The strongest risk factor for developing infective endocarditis is a previous episode of the condition. The mitral valve is the most commonly affected valve.
The most common cause of infective endocarditis is Staphylococcus aureus, particularly in acute presentations and intravenous drug users. Historically, Streptococcus viridans was the most common cause, but this is no longer the case except in developing countries. Streptococcus mitis and Streptococcus sanguinis are the two most notable viridans streptococci, commonly found in the mouth and dental plaque. Coagulase-negative Staphylococci such as Staphylococcus epidermidis are the most common cause of endocarditis in patients following prosthetic valve surgery.
Streptococcus bovis is associated with colorectal cancer, with the subtype Streptococcus gallolyticus being most linked to the condition. Non-infective causes of endocarditis include systemic lupus erythematosus and malignancy. Culture negative causes may be due to prior antibiotic therapy or infections caused by Coxiella burnetii, Bartonella, Brucella, or HACEK organisms (Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, Kingella).
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This question is part of the following fields:
- Infectious Diseases
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Question 54
Correct
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A 25-year-old woman presents to the Genitourinary Medicine Clinic with a 1-week history of lower abdominal pain and deep dyspareunia. She has also noticed a creamy foul-smelling vaginal discharge. There is no past medical history of note and she takes no regular medications.
On examination, her temperature is 38.1 °C. The remainder of her observations are within normal limits. There is palpable lower abdominal tenderness and guarding in the left iliac fossa. Bimanual examination elicits bilateral adnexal tenderness. There is no inguinal lymphadenopathy.
Given the likely diagnosis, what is the most appropriate investigation to confirm the causative organism?
Select ONE option onlyYour Answer: Nucleic acid amplification testing (NAAT)
Explanation:Investigations for Pelvic Inflammatory Disease
Pelvic inflammatory disease (PID) is a condition that can cause deep dyspareunia and lower abdominal and adnexal tenderness. The most common cause of PID is Chlamydia trachomatis, which can be diagnosed through nucleic acid amplification testing (NAAT). This involves taking a urine sample and a swab from the vagina or cervix to test for the organism. While a blood culture may be considered for a febrile patient, it is not routinely used for diagnosing C. trachomatis. Vaginal microscopy and culture used to be the preferred method for diagnosis, but NAAT is now recommended. Testing vaginal pH is commonly used for vaginal infections, but is not useful for PID. Urine microscopy and culture is used for UTIs, but the presence of vaginal discharge and deep dyspareunia suggests PID instead.
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This question is part of the following fields:
- Infectious Diseases
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Question 55
Correct
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A middle-aged man presents with a round, slowly enlarging erythema on his thigh. He also complains of joint discomfort and fatigue. Lyme disease is suspected.
Which of the following is the most appropriate laboratory test to confirm this diagnosis?
Select the SINGLE most appropriate laboratory test from the list below.Your Answer: Anti-Borrelia burgdorferi titre
Explanation:Diagnostic Tests for Lyme Disease: Understanding the Results
Lyme disease is a common illness caused by the spirochaete B. burgdorferi, transmitted to humans via tick bites. Serologic testing is the most frequently used diagnostic tool, but false positives and negatives are common. The enzyme immunoassay (EIA) or enzyme-linked immunosorbent assay (ELISA) is the first step, followed by a western blot if necessary. However, serologic results cannot distinguish active from inactive disease. Antinuclear antibodies and rheumatoid factor test results are negative in B. burgdorferi infection. The erythrocyte sedimentation rate is usually elevated but is not specific to detect infection. Culture of joint fluids can rule out gout and pseudogout, but detection of B. burgdorferi DNA in synovial fluid is not reliable. Blood cultures are impractical. Understanding the limitations of these tests is crucial for accurate diagnosis and treatment of Lyme disease.
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This question is part of the following fields:
- Infectious Diseases
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Question 56
Correct
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A 42-year-old woman, known to have human immunodeficiency virus (HIV), presents to the Emergency Department with reducing vision in her right eye. Her last CD4 count, measured in clinic, was < 100 cells/mm3.
Which is the most likely cause?Your Answer: Cytomegalovirus (CMV) retinitis
Explanation:Eye Conditions in Immunocompromised Patients
Cytomegalovirus (CMV) retinitis, acute glaucoma, age-related macular degeneration, molluscum contagiosum of eyelids, and uveitis are all potential eye conditions that can affect immunocompromised patients.
CMV retinitis is a common cause of eye disease in patients with HIV, causing necrotising retinitis with visual loss. Fundoscopy demonstrates a characteristic âpizza pieâ picture, with flame-shaped haemorrhages and retinal infarction. Treatment involves local and/or systemic delivery of antiviral agents such as ganciclovir, valganciclovir, or foscarnet.
Acute glaucoma is a medical emergency that presents with sudden onset of severe unilateral eye pain, vomiting, red-eye, and seeing lights distorted by haloes and decreasing vision. It is not associated with HIV/low CD4+ counts.
Age-related macular degeneration is a chronic and progressive condition affecting older people, resulting in a gradual loss of vision, particularly of the central vision. It is not related to HIV and typically presents as a chronic condition.
Molluscum contagiosum of eyelids is a viral skin infection that is more common in immunocompromised hosts. However, it tends to occur on the trunk, extremities, or abdomen, and involvement of the eyelid and buccal mucosa is uncommon.
Uveitis presents with eye pain, photophobia, blurring vision with loss of peripheral vision in some patients, redness in the eye, and possibly floaters in the vision. It is associated with HLA-B27, autoimmune conditions such as Crohnâs disease, and infections such as toxoplasmosis, tuberculosis, and Lyme disease. It is not associated with HIV, and pain and photophobia are normally very prominent symptoms.
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This question is part of the following fields:
- Infectious Diseases
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Question 57
Correct
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A 32-year-old woman comes to her General Practitioner complaining of dysuria and lower abdominal pain for the past three days. She has also noticed an unusual vaginal discharge since yesterday. She has been in a committed relationship for the past year and is sexually active. The urine dipstick is normal and her pregnancy test is negative.
What is the most suitable investigation to be performed next, given the most probable diagnosis?
Choose the SINGLE most appropriate investigation from the options below.
Your Answer: High vaginal swab for nucleic acid amplification test (NAAT)
Explanation:Investigations for Suspected Sexually Transmitted Infection in Women
When a woman presents with lower abdominal pain, dysuria, and vaginal discharge, it is important to consider the possibility of a sexually transmitted infection (STI), particularly if she is under 25 years old, has had a new sexual partner or multiple partners in the past year, or has a history of STIs. A high vaginal swab for nucleic acid amplification test (NAAT) is the investigation of choice in women suspected of having an STI, such as chlamydia or gonorrhoea. If the NAAT is positive for gonorrhoea, swabs are collected for culture to test for antibiotic susceptibility. Blood tests for inflammatory markers may be useful if an acute abdomen is suspected. HIV serology is not the next investigation in this case, but those diagnosed with STIs are offered screening for HIV. An ultrasound scan of the abdomen and pelvis may be done if a complicated pelvic inflammatory disease is suspected, but it is unlikely to be helpful in this case. Urine culture would not be useful in the absence of urinary symptoms.
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This question is part of the following fields:
- Infectious Diseases
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Question 58
Correct
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A 63-year-old woman is admitted to the medical ward with a 4-week history of fevers and lethargy. During the examination, you observe a few splinter haemorrhages in the fingernails and a loud systolic murmur at the apex. Your consultant advises you to obtain 3 sets of blood cultures and to schedule an echocardiogram. Microbiology contacts you later that day with the preliminary blood culture findings.
What organism is the most probable cause of the growth?Your Answer: Gram positive cocci
Explanation:Gram positive cocci are responsible for the majority of bacterial endocarditis cases. The most common culprits include Streptococcus viridans, Staphylococcus aureus (in individuals who use intravenous drugs or have prosthetic valves), and Staphylococcus epidermidis (in those with prosthetic valves). Other less common causes include Enterococcus, Streptococcus bovis, Candida, HACEK group, and Coxiella burnetii. Acute endocarditis is typically caused by Staphylococcus, while subacute cases are usually caused by Streptococcus species. Knowing the common underlying organisms is crucial for determining appropriate empirical antibiotic therapy. For native valve endocarditis, amoxicillin and gentamicin are recommended. Vancomycin and gentamicin are recommended for NVE with severe sepsis, penicillin allergy, or suspected methicillin-resistant Staphylococcus aureus (MRSA). Vancomycin and meropenem are recommended for NVE with severe sepsis and risk factors for gram-negative infection. For prosthetic valve endocarditis, vancomycin, gentamicin, and rifampicin are recommended. Once blood culture results are available, antibiotic therapy can be adjusted to provide specific coverage. Treatment typically involves long courses (4-6 weeks) of intravenous antibiotic therapy.
Aetiology of Infective Endocarditis
Infective endocarditis is a condition that affects patients with previously normal valves, rheumatic valve disease, prosthetic valves, congenital heart defects, intravenous drug users, and those who have recently undergone piercings. The strongest risk factor for developing infective endocarditis is a previous episode of the condition. The mitral valve is the most commonly affected valve.
The most common cause of infective endocarditis is Staphylococcus aureus, particularly in acute presentations and intravenous drug users. Historically, Streptococcus viridans was the most common cause, but this is no longer the case except in developing countries. Streptococcus mitis and Streptococcus sanguinis are the two most notable viridans streptococci, commonly found in the mouth and dental plaque. Coagulase-negative Staphylococci such as Staphylococcus epidermidis are the most common cause of endocarditis in patients following prosthetic valve surgery.
Streptococcus bovis is associated with colorectal cancer, with the subtype Streptococcus gallolyticus being most linked to the condition. Non-infective causes of endocarditis include systemic lupus erythematosus and malignancy. Culture negative causes may be due to prior antibiotic therapy or infections caused by Coxiella burnetii, Bartonella, Brucella, or HACEK organisms (Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, Kingella).
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This question is part of the following fields:
- Infectious Diseases
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Question 59
Incorrect
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The phlebotomist in a pediatric clinic sustains a needlestick injury while drawing blood from a child who is known to have HIV. After thoroughly washing the wound, what is the most suitable course of action?
Your Answer: HIV test of phlebotomist in 3 months to determine treatment
Correct Answer: Refer to Emergency Department + oral antiretroviral therapy for 4 weeks
Explanation:Oral antiretroviral therapy for 4 weeks is used as post-exposure prophylaxis for HIV.
Post-exposure prophylaxis (PEP) is a preventive treatment given to individuals who have been exposed to an infectious disease. The type of PEP given depends on the specific disease and the circumstances of the exposure.
For hepatitis A, either human normal immunoglobulin (HNIG) or the hepatitis A vaccine may be used.
For hepatitis B, if the source is HBsAg positive, a booster dose of the HBV vaccine should be given to known responders. Non-responders require hepatitis B immune globulin (HBIG) and a booster vaccine. If the source is unknown, known responders may receive a booster dose of the HBV vaccine, while known non-responders require HBIG and a vaccine. Those in the process of being vaccinated should have an accelerated course of the HBV vaccine.
For hepatitis C, monthly PCR is recommended, and if seroconversion occurs, interferon +/- ribavirin may be given.
For HIV, the risk of transmission depends on the incident and the current viral load of the patient. Low-risk incidents such as human bites generally do not require PEP. However, for high-risk incidents, a combination of oral antiretrovirals should be given as soon as possible for four weeks. For varicella zoster, VZIG is recommended for IgG negative pregnant women or immunosuppressed individuals. It is important to note that the risk of transmission varies depending on the virus, with hepatitis B having a higher risk than hepatitis C and HIV.
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This question is part of the following fields:
- Infectious Diseases
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Question 60
Incorrect
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A 25-year-old farm worker is admitted to hospital with a 5-day history of headache, fever, severe myalgia and a petechial rash. He is jaundiced, febrile, has tachycardia and has not passed urine for over 14 hours. His urea level is raised and liver function tests indicate hepatocellular damage.
Which of the following is the most likely diagnosis?
Your Answer: Brucellosis
Correct Answer: Weilâs disease
Explanation:Comparing Zoonotic Infections: Symptoms and Characteristics
Weil’s Disease, Brucellosis, Lyme Disease, Orf, and Rat-bite Fever are all zoonotic infections that can be transmitted from animals to humans. However, each infection has its own unique symptoms and characteristics.
Weil’s Disease is a severe form of leptospirosis caused by Leptospira icterohaemorrhagiae. It is transmitted via direct or indirect contact with animals, especially rodents. Symptoms include flu-like symptoms, severe headache, petechial or purpuric rashes, epistaxis, jaundice, renal failure, meningism, and multiorgan failure.
Brucellosis is caused by the bacterial genus Brucella and is transmitted from animals to humans by ingestion of infected food products, direct contact with an infected animal, or inhalation of aerosols. Symptoms include fever, myalgia, weight loss, coughing, vomiting, lymphadenopathy, and splenomegaly. Males may develop epididymo-orchitis.
Lyme Disease is caused by Borrelia burgdorferi and is transmitted to humans via tick bites from infected ticks. Symptoms include isolated erythema migrans, the characteristic skin rash which has the appearance of a ‘bullâs eye’ and a febrile illness. Untreated patients may go on to develop cardiac, neurological or rheumatological symptoms months after the initial bite.
Orf is a zoonotic mucocutaneous lesion caused by a pox virus and is most commonly seen in workers who handle sheep. Symptoms include firm red papules that develop, enlarge, and become painful before spontaneously resolving. Systemic illness is rare with orf.
Rat-bite Fever is an acute, febrile illness caused by bacteria transmitted by rodents. Symptoms include fever, a rash, and polyarthritis. The rash is usually widespread and may be maculopapular, petechial, or purpuric.
In summary, each zoonotic infection has its own unique symptoms and characteristics, making it important to accurately diagnose and treat each infection accordingly.
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This question is part of the following fields:
- Infectious Diseases
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Question 61
Correct
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A 35-year-old woman presents with fatigue, fever, dry cough, headache, chest discomfort and worsening difficulty breathing. She works as a factory worker in a plant that produces air filters.
Which of the following pathogens is the most probable cause of this illness?Your Answer: Legionella species
Explanation:Differentiating Between Possible Causes of Pneumonia
Pneumonia can be caused by a variety of pathogens, making it important to identify the specific cause in order to provide appropriate treatment. Legionella pneumophila is a common cause of community-acquired and nosocomial pneumonia in adults, often transmitted through contaminated water sources. Chlamydophila psittaci can cause pneumonia after exposure to infected birds, while Staphylococcus aureus can cause various infections when skin or mucosal barriers are breached. Mycoplasma pneumoniae typically causes mild respiratory tract infections, while different groups of Streptococci can cause a range of infections including pneumonia. In this clinical scenario, the patient’s occupation and symptoms suggest an atypical infection, making Legionella pneumophila the most probable cause.
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This question is part of the following fields:
- Infectious Diseases
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Question 62
Correct
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You want to screen a 60-year-old patient for hepatitis B. What is the most appropriate test to conduct?
Your Answer: HBsAg
Explanation:If the result of the anti-HBs test is positive, it means that the person is immune to hepatitis B either through vaccination or previous infection. On the other hand, a positive HBsAg test indicates that the person is currently infected with hepatitis B, either in its acute or chronic form.
Interpreting hepatitis B serology is an important skill that is still tested in medical exams. It is crucial to keep in mind a few key points. The surface antigen (HBsAg) is the first marker to appear and triggers the production of anti-HBs. If HBsAg is present for more than six months, it indicates chronic disease, while its presence for one to six months implies acute disease. Anti-HBs indicates immunity, either through exposure or immunization, and is negative in chronic disease. Anti-HBc indicates previous or current infection, with IgM anti-HBc appearing during acute or recent hepatitis B infection and persisting IgG anti-HBc. HbeAg is a marker of infectivity and HBV replication.
To illustrate, if someone has been previously immunized, their anti-HBs will be positive, while all other markers will be negative. If they had hepatitis B more than six months ago but are not a carrier, their anti-HBc will be positive, and HBsAg will be negative. However, if they are now a carrier, both anti-HBc and HBsAg will be positive. If HBsAg is present, it indicates an ongoing infection, either acute or chronic if present for more than six months. On the other hand, anti-HBc indicates that the person has caught the virus, and it will be negative if they have been immunized.
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This question is part of the following fields:
- Infectious Diseases
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Question 63
Correct
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A 21-year-old woman comes to her General Practitioner with cough, fever and rash. She is tachycardic, tachypnoeic and has a blanching erythematous rash on her face, trunk and arms with scattered white/grey papular lesions on the buccal mucosa. What is the most probable diagnosis?
Your Answer: Measles
Explanation:Measles is a highly contagious disease that can affect people of all ages, although it is commonly associated with childhood. The disease is characterized by the appearance of Koplik spots, which are white-grey specks that develop on the buccal mucosa opposite the second molars about 1-2 days before the rash. The rash typically appears 14 days after exposure and consists of erythematous macules and papules that start on the face and spread to the trunk and extremities, including the palms and soles. The rash lasts for 5-7 days before fading into hyperpigmented patches that eventually desquamate.
Meningococcaemia is a condition where meningococci (Neisseria meningitidis) spread into the bloodstream. Patients with acute meningococcaemia may present with or without meningitis and typically have a non-blanching petechial rash that spreads rapidly and may develop into purpura. However, the rash described in this case is not typical for meningococcaemia.
Rubella is a communicable disease that is usually benign, with nearly half of infected individuals being asymptomatic. The disease can have teratogenic effects on pregnant women. The rash associated with rubella is a rose-pink maculopapular rash that may be pruritic in adults. The Forchheimer sign may be present on the soft palate, but the buccal lesions described in this case are typical of Koplik spots, which are pathognomonic for measles.
Parvovirus B19 infection typically occurs in young children and is characterized by a bright red macular exanthema that appears on the cheeks (known as slapped cheek) and may be associated with circumoral pallor. However, the buccal lesions described in this case are typical of Koplik spots, which are not a feature of parvovirus B19 infection.
Secondary syphilis usually presents with a cutaneous eruption within 2-10 weeks after the primary chancre and is most florid 3-4 months after infection. The rash is typically rough red or red/brown papules or plaques on the trunk, palms, and soles. While there may be red patches on mucosal surfaces, the white patches described in this case are typical of Koplik spots.
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This question is part of the following fields:
- Infectious Diseases
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Question 64
Incorrect
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A 23-year-old male patient complains of fatigue and a persistent sore throat for the last two weeks. During the examination, his temperature is 37.8ÂșC, pulse rate is 78/min, and there is widespread cervical lymphadenopathy with palatal petechiae. What is the potential complication that this patient may face due to the likely diagnosis?
Your Answer: Encephalitis
Correct Answer: Splenic rupture
Explanation:It is recommended to refrain from participating in contact sports for a period of 4 weeks if diagnosed with glandular fever.
Understanding Infectious Mononucleosis
Infectious mononucleosis, also known as glandular fever, is a viral infection caused by the Epstein-Barr virus (EBV) in 90% of cases. It is most commonly seen in adolescents and young adults. The classic triad of symptoms includes sore throat, pyrexia, and lymphadenopathy, which are present in around 98% of patients. Other symptoms include malaise, anorexia, headache, palatal petechiae, splenomegaly, hepatitis, lymphocytosis, haemolytic anaemia, and a maculopapular rash. The symptoms typically resolve after 2-4 weeks.
The diagnosis of infectious mononucleosis is confirmed through a heterophil antibody test (Monospot test) in the second week of the illness. Management is supportive and includes rest, drinking plenty of fluids, avoiding alcohol, and taking simple analgesia for any aches or pains. It is recommended to avoid playing contact sports for 4 weeks after having glandular fever to reduce the risk of splenic rupture.
Interestingly, there is a correlation between EBV and socioeconomic groups. Lower socioeconomic groups have high rates of EBV seropositivity, having frequently acquired EBV in early childhood when the primary infection is often subclinical. However, higher socioeconomic groups show a higher incidence of infectious mononucleosis, as acquiring EBV in adolescence or early adulthood results in symptomatic disease.
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This question is part of the following fields:
- Infectious Diseases
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Question 65
Correct
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A 5-day-old infant presents with congenital cataracts, sensorineural deafness, and pulmonary artery stenosis. What is the probable prenatal infection that the baby has been exposed to?
Your Answer: Rubella
Explanation:The neonate is diagnosed with congenital rubella syndrome, which is characterized by sensorineural deafness, eye abnormalities, and congenital heart disease. The risk of fetal infection is highest if the mother contracts the virus during the first trimester of pregnancy. Antenatal cytomegalovirus infection can lead to cerebral calcification, microcephaly, and sensorineural deafness. HIV does not pose a physical risk to the developing fetus, but there is a risk of perinatal transmission. Parvovirus B19 can cause hydrops fetalis and fetal death. Toxoplasmosis can result in intracranial calcification, hydrocephalus, and epilepsy in the affected child.
Rubella and Pregnancy: Risks, Features, Diagnosis, and Management
Rubella, also known as German measles, is a viral infection caused by the togavirus. Thanks to the introduction of the MMR vaccine, it is now rare. However, if contracted during pregnancy, there is a risk of congenital rubella syndrome, which can cause serious harm to the fetus. It is important to note that the incubation period is 14-21 days, and individuals are infectious from 7 days before symptoms appear to 4 days after the onset of the rash.
The risk of damage to the fetus is highest in the first 8-10 weeks of pregnancy, with a risk as high as 90%. However, damage is rare after 16 weeks. Features of congenital rubella syndrome include sensorineural deafness, congenital cataracts, congenital heart disease (e.g. patent ductus arteriosus), growth retardation, hepatosplenomegaly, purpuric skin lesions, ‘salt and pepper’ chorioretinitis, microphthalmia, and cerebral palsy.
If a suspected case of rubella in pregnancy arises, it should be discussed immediately with the local Health Protection Unit (HPU) as type/timing of investigations may vary. IgM antibodies are raised in women recently exposed to the virus. It should be noted that it is very difficult to distinguish rubella from parvovirus B19 clinically. Therefore, it is important to also check parvovirus B19 serology as there is a 30% risk of transplacental infection, with a 5-10% risk of fetal loss.
If a woman is tested at any point and no immunity is demonstrated, they should be advised to keep away from people who might have rubella. Non-immune mothers should be offered the MMR vaccination in the post-natal period. However, MMR vaccines should not be administered to women known to be pregnant or attempting to become pregnant.
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This question is part of the following fields:
- Infectious Diseases
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Question 66
Correct
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A 25-year-old patient visits their doctor with suspected tonsillitis recurrence. They report having had tonsillitis three times in the past year and currently have a fever and cough. During the examination, the doctor notes tender cervical lymphadenopathy and exudative tonsils. The patient is prescribed phenoxymethylpenicillin. On day 5 of treatment, blood tests are taken and reveal the following results:
Hb 150 g/L Male: (135-180) Female: (115 - 160)
Platelets 390 * 109/L (150 - 400)
WBC 10.2 * 109/L (4.0 - 11.0)
Neuts 0.8 * 109/L (2.0 - 7.0)
Lymphs 9.2 * 109/L (1.0 - 3.5)
Mono 0.2 * 109/L (0.2 - 0.8)
Eosin 0.0 * 109/L (0.0 - 0.4)
What could be the possible reasons for the abnormalities in these blood results?Your Answer: Underlying diagnosis of glandular fever
Explanation:The presence of lymphocytosis and neutropenia in a person who has been treated for recurrent tonsillitis may indicate an underlying condition. Glandular fever, caused by the Epstein-Barr virus, is a common cause of recurrent tonsillitis in young people and can result in an increase in activated T and B lymphocytes, leading to lymphocytosis. The virus may also cause neutropenia, although the exact cause is not fully understood. A peritonsillar abscess, tonsillitis unresponsive to treatment, and treatment with phenoxymethylpenicillin are unlikely to cause significant abnormalities in the full blood count. While lymphoma may explain the lymphocytosis, it would not account for the neutropenia and is less likely than an underlying glandular fever infection.
Understanding Neutropaenia: Causes and Severity
Neutropaenia is a medical condition characterized by low neutrophil counts, which is below 1.5 * 109. A normal neutrophil count ranges from 2.0 to 7.5 * 109. It is crucial to recognize this condition as it increases the risk of severe infections. Neutropaenia can be classified into three categories based on its severity: mild (1.0 – 1.5 * 109), moderate (0.5 – 1.0 * 109), and severe (< 0.5 * 109). There are several causes of neutropaenia, including viral infections such as HIV, Epstein-Barr virus, and hepatitis. Certain drugs like cytotoxics, carbimazole, and clozapine can also cause neutropaenia. Benign ethnic neutropaenia is common in people of black African and Afro-Caribbean ethnicity, but it requires no treatment. Haematological malignancies like myelodysplastic malignancies and aplastic anemia, as well as rheumatological conditions like systemic lupus erythematosus and rheumatoid arthritis, can also cause neutropaenia. Severe sepsis and haemodialysis are other potential causes of neutropaenia. In summary, neutropaenia is a medical condition that can increase the risk of severe infections. It is important to recognize its severity and underlying causes to provide appropriate treatment and management.
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This question is part of the following fields:
- Infectious Diseases
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Question 67
Incorrect
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A 50-year-old man has presented to the emergency department with a 2-day history of bloody diarrhoea 10 times per day associated with colicky abdominal pain.
Observations are as follows: blood pressure 100/60 mmHg, pulse 90/min, respiratory rate 15/min, temperature 37.8ÂșC, oxygen saturation 97% on air. The examination is unremarkable apart from diffuse abdominal tenderness.
Stool analysis revealed Campylobacter jejuni.
What is the first-line treatment?Your Answer: Ciprofloxacin
Correct Answer: Clarithromycin
Explanation:If a patient experiences severe symptoms of Campylobacter infection such as bloody diarrhea and more than eight stools per day, treatment with clarithromycin may be necessary. While Campylobacter infection is typically self-limiting, the British National Formulary (BNF) recommends antibiotics for severe cases or for immunocompromised patients. NICE also advises antibiotic treatment for severe symptoms or if symptoms persist for more than one week. Supportive treatment may be sufficient for mild symptoms in immunocompetent patients. Ciprofloxacin is an alternative to clarithromycin, but strains with decreased sensitivity to ciprofloxacin are frequently isolated. Metronidazole and oral vancomycin are not recommended for Campylobacter treatment, but are first-line options for Clostridium difficile.
Campylobacter: The Most Common Bacterial Cause of Intestinal Disease in the UK
Campylobacter is a Gram-negative bacillus that is responsible for causing infectious intestinal disease in the UK. The bacteria is primarily spread through the faecal-oral route and has an incubation period of 1-6 days. Symptoms of Campylobacter infection include a prodrome of headache and malaise, diarrhoea (often bloody), and abdominal pain that may mimic appendicitis.
In most cases, Campylobacter infection is self-limiting and does not require treatment. However, the British National Formulary (BNF) recommends treatment with antibiotics if the patient is immunocompromised or if symptoms are severe (high fever, bloody diarrhoea, or more than eight stools per day) and have lasted for more than one week. The first-line antibiotic for Campylobacter infection is clarithromycin, although ciprofloxacin is an alternative. It is important to note that strains with decreased sensitivity to ciprofloxacin are frequently isolated.
Complications of Campylobacter infection may include Guillain-Barre syndrome, reactive arthritis, septicaemia, endocarditis, and arthritis. It is important to seek medical attention if symptoms are severe or persist for an extended period of time.
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This question is part of the following fields:
- Infectious Diseases
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Question 68
Correct
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Which of the following vaccinations should be avoided in individuals who have HIV, and what is the reason for this recommendation?
Your Answer: BCG
Explanation:Live attenuated vaccines include BCG, MMR, oral polio, yellow fever, and oral typhoid.
Types of Vaccines and Their Characteristics
Vaccines are essential in preventing the spread of infectious diseases. However, it is crucial to understand the different types of vaccines and their characteristics to ensure their safety and effectiveness. Live attenuated vaccines, such as BCG, MMR, and oral polio, may pose a risk to immunocompromised patients. In contrast, inactivated preparations, including rabies and hepatitis A, are safe for everyone. Toxoid vaccines, such as tetanus, diphtheria, and pertussis, use inactivated toxins to generate an immune response. Subunit and conjugate vaccines, such as pneumococcus, haemophilus, meningococcus, hepatitis B, and human papillomavirus, use only part of the pathogen or link bacterial polysaccharide outer coats to proteins to make them more immunogenic. Influenza vaccines come in different types, including whole inactivated virus, split virion, and sub-unit. Cholera vaccine contains inactivated strains of Vibrio cholerae and recombinant B-subunit of the cholera toxin. Hepatitis B vaccine contains HBsAg adsorbed onto aluminium hydroxide adjuvant and is prepared from yeast cells using recombinant DNA technology. Understanding the different types of vaccines and their characteristics is crucial in making informed decisions about vaccination.
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This question is part of the following fields:
- Infectious Diseases
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Question 69
Correct
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A 65-year-old woman presents to the emergency department with a 4-day history of increased shortness of breath, cough with green sputum, and reduced exercise tolerance. She has a history of COPD and is currently on a salbutamol inhaler, combined glycopyrronium and indacaterol inhaler, and oral prednisolone to manage her symptoms. She is being evaluated for BIPAP home therapy. On examination, her respiratory rate is 22/min, oxygen saturations are 85% in room air, heart rate is 86/min, temperature is 37.7ÂșC, and blood pressure is 145/78 mmHg. What is the most likely causative organism for her presentation?
Your Answer: Haemophilus influenzae
Explanation:The most frequent cause of infective exacerbations of COPD is Haemophilus influenzae, according to research. This bacterium’s strains that cause COPD exacerbations are more virulent and induce greater airway inflammation than those that only colonize patients without causing symptoms. Patients with COPD have reduced mucociliary clearance, making them susceptible to H. influenzae, which can lead to airway inflammation and increased breathing effort. Coxsackievirus is linked to hand, foot, and mouth disease, which primarily affects children but can also affect immunocompromised adults. This option is incorrect because the patient does not have the typical symptoms of sore throat, fever, and maculopapular rash on hands, foot, and mucosa. Influenza A virus is associated with the bird flu pandemic and is not the most common cause of infective exacerbations of COPD. Staphylococcus aureus is not commonly associated with infective exacerbations of COPD. This bacterium is more commonly seen in mild cases of skin infections or can lead to infective endocarditis and is associated with biofilms causing infection.
Acute exacerbations of COPD are a common reason for hospital visits in developed countries. The most common causes of these exacerbations are bacterial infections, with Haemophilus influenzae being the most common culprit, followed by Streptococcus pneumoniae and Moraxella catarrhalis. Respiratory viruses also account for around 30% of exacerbations, with human rhinovirus being the most important pathogen. Symptoms of an exacerbation include an increase in dyspnea, cough, and wheezing, as well as hypoxia and acute confusion in some cases.
NICE guidelines recommend increasing the frequency of bronchodilator use and giving prednisolone for five days. Antibiotics should only be given if sputum is purulent or there are clinical signs of pneumonia. Admission to the hospital is recommended for patients with severe breathlessness, acute confusion or impaired consciousness, cyanosis, oxygen saturation less than 90%, social reasons, or significant comorbidity.
For severe exacerbations requiring secondary care, oxygen therapy should be used with an initial saturation target of 88-92%. Nebulized bronchodilators such as salbutamol and ipratropium should also be administered, along with steroid therapy. IV hydrocortisone may be considered instead of oral prednisolone, and IV theophylline may be used for patients not responding to nebulized bronchodilators. Non-invasive ventilation may be used for patients with type 2 respiratory failure, with bilevel positive airway pressure being the typical method used.
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This question is part of the following fields:
- Infectious Diseases
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Question 70
Correct
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A 63-year-old patient with type 2 diabetes mellitus complains of a 'rash' on their left shin. The rash has increased in size over the last two days and is now a painful, hot, red area on their anterior left shin that spreads around to the back of the leg. The patient is feeling well overall, and it is decided that oral treatment is the best course of action. The patient has a history of penicillin allergy. What is the best antibiotic to prescribe?
Your Answer: Clarithromycin
Explanation:Understanding Cellulitis: Symptoms, Diagnosis, and Treatment
Cellulitis is a condition characterized by inflammation of the skin and subcutaneous tissues caused by bacterial infection, usually Streptococcus pyogenes or Staphylcoccus aureus. It commonly occurs on the shins and is accompanied by symptoms such as erythema, pain, and swelling. In some cases, patients may also experience systemic upset, including fever.
The diagnosis of cellulitis is typically made based on clinical presentation, and no further investigations are required in primary care. However, blood tests and cultures may be requested if the patient is admitted to the hospital and sepsis is suspected.
To guide the management of patients with cellulitis, healthcare providers may use the Eron classification system. Patients with Eron Class III or IV cellulitis, severe or rapidly deteriorating cellulitis, or certain risk factors such as immunocompromisation or significant lymphoedema should be admitted for intravenous antibiotics. Patients with Eron Class II cellulitis may not require admission if appropriate facilities and expertise are available in the community to administer intravenous antibiotics and monitor the patient.
The first-line treatment for mild to moderate cellulitis is flucloxacillin, while clarithromycin, erythromycin (in pregnancy), or doxycycline may be used in patients allergic to penicillin. Patients with severe cellulitis should be offered co-amoxiclav, cefuroxime, clindamycin, or ceftriaxone.
Overall, understanding the symptoms, diagnosis, and treatment of cellulitis is crucial for effective management of this common bacterial infection.
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This question is part of the following fields:
- Infectious Diseases
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Question 71
Correct
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You are invited to a meeting at a nearby daycare center. There has been a rise in the number of children contracting hand, foot, and mouth disease and a plan is being developed to address this issue. What is the most efficient measure to decrease the occurrence of hand, foot, and mouth disease?
Your Answer: Hand hygiene
Explanation:Hand hygiene is the most crucial step in addressing MRSA, although a comprehensive approach is necessary.
Understanding MRSA and Screening for Infection
Methicillin-resistant Staphylococcus aureus (MRSA) is a type of bacteria that can cause serious infections and is particularly dangerous in hospital settings. To prevent the spread of MRSA, certain patients should be screened for the infection, including those awaiting elective admissions and all emergency admissions starting in 2011. Screening involves taking a nasal swab and checking for skin lesions or wounds. If a patient is found to be a carrier of MRSA, treatment involves using antibiotics such as vancomycin, teicoplanin, or linezolid. However, some strains may develop resistance to these antibiotics, so newer options like linezolid, quinupristin/dalfopristin combinations, and tigecycline should be reserved for resistant cases. It is important to suppress MRSA from carriers to prevent the spread of infection. This can be done through the use of mupirocin and chlorhexidine gluconate. By understanding MRSA and screening for infection, healthcare providers can take steps to prevent the spread of this dangerous bacteria.
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This question is part of the following fields:
- Infectious Diseases
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Question 72
Incorrect
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A 6-year-old girl is brought to her general practitioner by her mother, with a 3-day history of fever up to 37.8 °C. She had no history of lesions on the buccal mucosa but developed a maculopapular rash across the face and trunk. A few days before the appearance of the rash, she complained of some eye pain, sore throat and general body aches. On physical examination, she has a discrete rose-pink maculopapular rash on the face, neck and trunk, low-grade fever and enlarged posterior auricular and suboccipital lymph nodes.
What is the most likely diagnosis?Your Answer: Erythema infectiosum
Correct Answer: Rubella
Explanation:Distinguishing Between Viral Diseases: Rubella, Mumps, Meningitis, Scarlet Fever, and Erythema Infectiosum
Rubella, also known as German measles, is a typically mild viral disease that often goes unnoticed, with almost half of those infected showing no symptoms. However, it can have severe consequences for pregnant women, especially in the early stages of pregnancy. Symptoms include eye pain, sore throat, low-grade fever, and a rose-pink rash that starts on the face and spreads to the trunk and extremities within 24 hours.
Mumps is another viral disease caused by rubulavirus. It typically presents with low-grade fever, malaise, headache, and myalgia, followed by painful swelling of the salivary glands and tender cervical lymphadenopathy. Mumps is highly contagious and has become less common in developing countries due to vaccination.
Meningitis is a serious condition characterized by inflammation of the meninges. Symptoms include fever, headache, and neck stiffness, and it requires urgent medical attention.
Scarlet fever is caused by group A ÎČ-hemolytic streptococci and presents with exudative pharyngitis, fever, and a bright red rash. It typically evolves from a tonsillar/pharyngeal focus and is uncommon without buccal lesions.
Erythema infectiosum, also known as fifth disease, is a mild childhood illness caused by parvovirus B19. It presents with a bright red rash on the cheeks and may have atypical rashes in adults.
It is important to distinguish between these viral diseases to ensure proper treatment and prevent complications.
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This question is part of the following fields:
- Infectious Diseases
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Question 73
Incorrect
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A 25-year-old hiker comes to you with complaints of fever, joint pain, and a red rash after being bitten by a tick during a recent hike. Upon examination, you find that his neurological and cardiovascular functions are normal. You suspect that he may have contracted Lyme disease and have ordered serology for Borrelia burgdorferi. What would be the most suitable course of action for managing this condition?
Your Answer: 7 day course of doxycycline
Correct Answer: 14 day course of doxycycline
Explanation:The recommended initial treatment for early Lyme disease is a 14-21 day regimen of oral doxycycline. For non-disseminated Lyme disease, the first line treatment is a 14-day course of oral doxycycline, making option 2 the correct answer. Amoxicillin may be used if doxycycline is contraindicated, such as during pregnancy. Ceftriaxone is reserved for disseminated disease. Treatment should be initiated based on clinical suspicion, as serology may take several weeks to become positive.
Understanding Lyme Disease
Lyme disease is a bacterial infection caused by Borrelia burgdorferi and is transmitted through tick bites. The early symptoms of Lyme disease include erythema migrans, a characteristic bulls-eye rash that appears at the site of the tick bite. This rash is painless, slowly increases in size, and can be more than 5 cm in diameter. Other early symptoms include headache, lethargy, fever, and joint pain.
If erythema migrans is present, Lyme disease can be diagnosed clinically, and antibiotics should be started immediately. The first-line test for Lyme disease is an enzyme-linked immunosorbent assay (ELISA) to detect antibodies to Borrelia burgdorferi. If the ELISA is negative but Lyme disease is still suspected, it should be repeated 4-6 weeks later. If Lyme disease is suspected in patients who have had symptoms for 12 weeks or more, an immunoblot test should be done.
Tick bites can cause significant anxiety, but routine antibiotic treatment is not recommended by NICE. If the tick is still present, it should be removed using fine-tipped tweezers, and the area should be washed. In cases of suspected or confirmed Lyme disease, doxycycline is the preferred treatment for early disease, while ceftriaxone is used for disseminated disease. A Jarisch-Herxheimer reaction may occur after initiating therapy, which can cause fever, rash, and tachycardia.
In summary, Lyme disease is a bacterial infection transmitted through tick bites. Early symptoms include erythema migrans, headache, lethargy, fever, and joint pain. Diagnosis is made through clinical presentation and ELISA testing, and treatment involves antibiotics. Tick bites do not require routine antibiotic treatment, and ticks should be removed using fine-tipped tweezers.
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This question is part of the following fields:
- Infectious Diseases
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Question 74
Correct
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A 28-year-old known to be HIV positive comes to the clinic complaining of diarrhoea that has been ongoing for 2 days. What is the probable cause of his diarrhoea?
Your Answer: Cryptosporidium
Explanation:Patients with HIV infection commonly experience diarrhoea as a result of Cryptosporidium, while respiratory infection may be caused by Histoplasmosis.
Diarrhoea in HIV Patients: Causes and Management
Diarrhoea is a common symptom experienced by patients with HIV. It can be caused by the virus itself, known as HIV enteritis, or by opportunistic infections. The most common infective cause of diarrhoea in HIV patients is Cryptosporidium, an intracellular protozoa with an incubation period of 7 days. Symptoms can range from mild to severe diarrhoea, and diagnosis is made through a modified Ziehl-Neelsen stain of the stool. Unfortunately, treatment is difficult, and supportive therapy is the mainstay of management.
Other possible causes of diarrhoea in HIV patients include Cytomegalovirus, Mycobacterium avium intracellulare, and Giardia. Mycobacterium avium intracellulare is an atypical mycobacteria that is typically seen when the CD4 count is below 50. Symptoms include fever, sweats, abdominal pain, and diarrhoea, and diagnosis is made through blood cultures and bone marrow examination. Management involves the use of rifabutin, ethambutol, and clarithromycin.
In summary, diarrhoea is a common symptom experienced by HIV patients, and it can be caused by a variety of opportunistic infections. While treatment can be difficult, supportive therapy can help manage symptoms. It is important for healthcare providers to be aware of the potential causes of diarrhoea in HIV patients and to work with their patients to develop an appropriate management plan.
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This question is part of the following fields:
- Infectious Diseases
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Question 75
Correct
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A 29-year-old man who has recently arrived in the UK from Uganda visits the clinic with complaints of exhaustion and purple skin lesions all over his body. During the examination, you observe multiple raised purple lesions on his trunk and arms. Additionally, you notice some smaller purple lesions in his mouth. He has recently initiated acyclovir treatment for herpes zoster infection. What is the probable diagnosis?
Your Answer: Kaposi's sarcoma
Explanation:The presence of raised purple lesions is a typical indication of Kaposi’s sarcoma, which may suggest that the patient has an underlying HIV infection. Given the high prevalence of HIV in Uganda and the recent occurrence of herpes zoster, it is possible that the patient’s immune system is compromised. Dermatofibromas, which are typically small and firm, would not be found in the mouth, while psoriasis is characterized by red, scaly lesions that do not appear on mucosal surfaces. A drug reaction is an unlikely explanation for the patient’s symptoms. Although a haemangioma can present as a purple raised lesion, it is uncommon to find them in the mouth, and Kaposi’s sarcoma is a more likely diagnosis in this case.
Kaposi’s Sarcoma in HIV Patients
Kaposi’s sarcoma is a type of cancer that is commonly seen in patients with HIV. It is caused by the human herpes virus 8 (HHV-8) and is characterized by the appearance of purple papules or plaques on the skin or mucosa. These lesions may later ulcerate, causing discomfort and pain. In some cases, respiratory involvement may occur, leading to massive haemoptysis and pleural effusion.
Treatment for Kaposi’s sarcoma typically involves a combination of radiotherapy and resection. This can help to reduce the size of the lesions and prevent further spread of the cancer. However, it is important to note that Kaposi’s sarcoma can be a serious and potentially life-threatening condition, particularly in patients with HIV. As such, it is important for individuals with HIV to be regularly screened for this condition and to seek prompt medical attention if any symptoms are present.
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This question is part of the following fields:
- Infectious Diseases
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Question 76
Correct
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A 54-year-old man with a recent diagnosis of fatty liver disease presents at the clinic. During a liver screen to determine the cause of his condition, his hepatitis B serology is tested and the results are as follows:
- HBsAg: Negative
- HBcAg: Negative
- Anti-HBs IgG: Positive
- Anti-HBc IgG: Positive
What is his hepatitis B status?Your Answer: Cleared previous infection
Explanation:To determine a patient’s immune status for Hepatitis B, a systematic approach is necessary. First, antigenic results are examined to determine if the virus is present, followed by antibody results to assess the body’s response to the virus. In this case, negative results for both HBsAg and HBcAg indicate no active infection, while the presence of antibodies to both antigens suggests a previous infection that has been cleared, resulting in immunity.
In acute infection, both HBsAg and HBcAg are positive, with a limited antibody response. Chronic infection is characterized by ongoing viral infection and an inadequate immune response, resulting in the virus not being cleared. Immunization exposes the immune system to purified viral protein, resulting in the production of anti-HBs antibodies and conferring some immunity.
To distinguish between immunization and previous infection, the absence of anti-HBc antibodies indicates immunization, as there are no viral antigens present. If an individual has never been exposed to any Hepatitis B antigens, all serology tests would be negative.
Interpreting hepatitis B serology is an important skill that is still tested in medical exams. It is crucial to keep in mind a few key points. The surface antigen (HBsAg) is the first marker to appear and triggers the production of anti-HBs. If HBsAg is present for more than six months, it indicates chronic disease, while its presence for one to six months implies acute disease. Anti-HBs indicates immunity, either through exposure or immunization, and is negative in chronic disease. Anti-HBc indicates previous or current infection, with IgM anti-HBc appearing during acute or recent hepatitis B infection and persisting IgG anti-HBc. HbeAg is a marker of infectivity and HBV replication.
To illustrate, if someone has been previously immunized, their anti-HBs will be positive, while all other markers will be negative. If they had hepatitis B more than six months ago but are not a carrier, their anti-HBc will be positive, and HBsAg will be negative. However, if they are now a carrier, both anti-HBc and HBsAg will be positive. If HBsAg is present, it indicates an ongoing infection, either acute or chronic if present for more than six months. On the other hand, anti-HBc indicates that the person has caught the virus, and it will be negative if they have been immunized.
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This question is part of the following fields:
- Infectious Diseases
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Question 77
Correct
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A 21-year-old man is seeking advice as his girlfriend has been diagnosed with meningococcal meningitis. He is concerned about the possibility of contracting the disease. What is the recommended antibiotic prophylaxis for individuals in close contact with someone who has meningococcal meningitis?
Your Answer: Oral ciprofloxacin
Explanation:Prophylaxis for contacts of patients with meningococcal meningitis now favors the use of oral ciprofloxacin over rifampicin.
The investigation and management of suspected bacterial meningitis are intertwined due to the potential negative impact of delayed antibiotic treatment. Patients should be urgently transferred to the hospital, and an ABC approach should be taken initially. A lumbar puncture should be delayed in certain circumstances, and IV antibiotics should be given as a priority if there is any doubt. The bloods and CSF should be tested for various parameters, and prophylaxis should be offered to households and close contacts of patients affected with meningococcal meningitis.
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This question is part of the following fields:
- Infectious Diseases
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Question 78
Correct
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A 56-year-old woman with a history of rheumatoid arthritis complains of bloody diarrhoea, accompanied by fever and abdominal pain for the past week. She is on methotrexate for her rheumatoid arthritis, which is usually well-controlled. Upon testing her stool sample, Campylobacter jejuni is detected. What is the best course of action for treatment?
Your Answer: Fluids + clarithromycin
Explanation:Campylobacter: The Most Common Bacterial Cause of Intestinal Disease in the UK
Campylobacter is a Gram-negative bacillus that is responsible for causing infectious intestinal disease in the UK. The bacteria is primarily spread through the faecal-oral route and has an incubation period of 1-6 days. Symptoms of Campylobacter infection include a prodrome of headache and malaise, diarrhoea (often bloody), and abdominal pain that may mimic appendicitis.
In most cases, Campylobacter infection is self-limiting and does not require treatment. However, the British National Formulary (BNF) recommends treatment with antibiotics if the patient is immunocompromised or if symptoms are severe (high fever, bloody diarrhoea, or more than eight stools per day) and have lasted for more than one week. The first-line antibiotic for Campylobacter infection is clarithromycin, although ciprofloxacin is an alternative. It is important to note that strains with decreased sensitivity to ciprofloxacin are frequently isolated.
Complications of Campylobacter infection may include Guillain-Barre syndrome, reactive arthritis, septicaemia, endocarditis, and arthritis. It is important to seek medical attention if symptoms are severe or persist for an extended period of time.
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This question is part of the following fields:
- Infectious Diseases
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Question 79
Correct
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Which one of the following statements regarding listeria infection is accurate?
Your Answer: Pregnant women are 20 times more likely to develop listeriosis compared with the rest of the population
Explanation:Listeria monocytogenes is a type of bacteria that can cause serious illness in certain populations. This Gram-positive bacillus has the unique ability to multiply at low temperatures, making it a common contaminant in unpasteurized dairy products. The infection is particularly dangerous for pregnant women, as it can lead to miscarriage and other complications. Other at-risk populations include the elderly, neonates, and those with weakened immune systems.
Listeria infections can present in a variety of ways, including gastroenteritis, diarrhoea, bacteraemia, and flu-like illness. In severe cases, it can lead to central nervous system infections such as meningoencephalitis, ataxia, and seizures. Diagnosis is typically made through blood cultures or cerebrospinal fluid findings.
Treatment for Listeria infections typically involves antibiotics such as amoxicillin or ampicillin. In cases of Listeria meningitis, gentamicin may also be used. Pregnant women are at a particularly high risk for Listeria infection, and diagnosis can only be made through blood cultures. Treatment with amoxicillin is recommended to prevent complications such as miscarriage, premature labor, stillbirth, and chorioamnionitis.
Overall, Listeria is a dangerous bacterial infection that requires prompt diagnosis and treatment, particularly in at-risk populations.
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This question is part of the following fields:
- Infectious Diseases
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Question 80
Incorrect
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A 65-year-old woman presents to the emergency department with a 6 cm erythematous skin lesion on her upper arm after experiencing a high fever of 39ÂșC, headache, and vomiting for the past 48 hours. A skin biopsy revealed a beta-haemolytic group A streptococcal infection in the upper dermis. What is the most appropriate term to describe this condition?
Your Answer: Necrotizing fasciitis
Correct Answer: Erysipelas
Explanation:Erysipelas is mainly caused by Streptococcus pyogenes, which belongs to the beta-haemolytic group A streptococci. The rash is a result of an endotoxin produced by the bacteria, rather than the bacteria itself. The absence of subcutaneous tissue involvement is a distinguishing feature of erysipelas.
Antibiotic Guidelines for Common Infections
Respiratory infections, urinary tract infections, skin infections, ear, nose, and throat infections, genital infections, and gastrointestinal infections are some of the most common infections that require antibiotic treatment. The British National Formulary (BNF) provides guidelines for the appropriate use of antibiotics for these infections.
For respiratory infections such as chronic bronchitis, community-acquired pneumonia, and hospital-acquired pneumonia, antibiotics such as amoxicillin, tetracycline, clarithromycin, co-amoxiclav, cefuroxime, piperacillin with tazobactam, ceftazidime, or ciprofloxacin are recommended depending on the severity and type of infection.
For urinary tract infections, lower urinary tract infections can be treated with trimethoprim or nitrofurantoin, while acute pyelonephritis requires broad-spectrum cephalosporin or quinolone. Acute prostatitis can be treated with quinolone or trimethoprim.
Skin infections such as impetigo, cellulitis, erysipelas, and animal or human bites require antibiotics such as topical hydrogen peroxide, oral flucloxacillin, erythromycin, doxycycline, clarithromycin, or metronidazole depending on the severity and type of infection.
Ear, nose, and throat infections such as throat infections, sinusitis, otitis media, otitis externa, periapical or periodontal abscess, and acute necrotising ulcerative gingivitis require antibiotics such as phenoxymethylpenicillin, amoxicillin, erythromycin, or flucloxacillin depending on the severity and type of infection.
Genital infections such as gonorrhoea, chlamydia, pelvic inflammatory disease, syphilis, and bacterial vaginosis require antibiotics such as intramuscular ceftriaxone, doxycycline, azithromycin, ofloxacin, metronidazole, or benzathine benzylpenicillin depending on the severity and type of infection.
Gastrointestinal infections such as Clostridioides difficile, Campylobacter enteritis, Salmonella (non-typhoid), and Shigellosis require antibiotics such as oral vancomycin, oral fidaxomicin, clarithrom
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This question is part of the following fields:
- Infectious Diseases
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Question 81
Correct
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A 20-year-old male patient visits his GP clinic with a complaint of painful blisters and ulcers on his glans, accompanied by pain during urination. He is sexually active and does not use protection during intercourse. His last unprotected sexual encounter was a week ago. What medication would be beneficial for this patient?
Your Answer: Oral aciclovir
Explanation:Male patients with gonorrhea typically experience urethral discharge and dysuria as symptoms, rather than painful ulcers.
Understanding Genital Herpes
Genital herpes is a viral infection caused by the herpes simplex virus (HSV). There are two strains of the virus, HSV-1 and HSV-2, which were previously thought to cause oral and genital lesions respectively. However, there is now considerable overlap between the two strains. The infection is characterized by painful genital ulceration, which may be accompanied by dysuria and pruritus. Primary infections are usually more severe than recurrent episodes and may present with systemic symptoms such as headache, fever, and malaise. Tender inguinal lymphadenopathy and urinary retention may also occur.
To diagnose genital herpes, nucleic acid amplification tests (NAAT) are the preferred investigation method as they are considered superior to viral culture. HSV serology may be useful in certain situations, such as recurrent genital ulceration of unknown cause. Management of the infection involves general measures such as saline bathing, analgesia, and topical anaesthetic agents like lidocaine. Oral aciclovir is also prescribed, and some patients with frequent exacerbations may benefit from longer-term aciclovir.
In pregnant women, a primary attack of herpes occurring after 28 weeks gestation may require an elective caesarean section at term. Women with recurrent herpes who are pregnant should be treated with suppressive therapy and advised that the risk of transmission to their baby is low. Understanding genital herpes and its management is crucial in preventing transmission and managing symptoms.
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This question is part of the following fields:
- Infectious Diseases
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Question 82
Correct
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A 30-year-old teacher who recently returned after completing a 3-month assignment in Thailand presented to the Emergency Department with fever, headache, confusion and vomiting in the last two days. She was suspected of having meningitis and underwent a lumbar puncture (LP). The LP findings are as follows:
Normal opening pressure, clear cerebrospinal fluid (CSF).
Investigation Result Normal value
CSF white blood cell count (WBC) 400 cells/”l, 70% lymphocytes < 5 cells/”l
CSF protein 0.5 g/l 0.15â0.4 g/l
CSF glucose 3.8 mmol/l 2.6â4.5 mmol/l
CSFâplasma-glucose ratio 0.72 â„ 0.66
What is the most likely diagnosis?
Select the SINGLE best answer from the list below.
Select ONE option onlyYour Answer: Viral meningitis
Explanation:The cerebrospinal fluid (CSF) findings can help diagnose different types of meningitis. Viral meningitis typically shows clear CSF with a slightly elevated white blood cell count (5-1000 cells/”l, mostly lymphocytes), mildly elevated protein levels, and a normal or slightly low CSF-to-plasma-glucose ratio. Bacterial meningitis, on the other hand, often presents with turbid CSF, a high white blood cell count (>100 cells/”l, mostly neutrophils), elevated protein levels, and a very low CSF-to-plasma-glucose ratio. Fungal meningitis, such as cryptococcal meningitis, usually shows clear or cloudy CSF, a slightly elevated white blood cell count (5-100 cells/”l, mostly lymphocytes), elevated protein levels, and a low CSF-to-plasma-glucose ratio. Tuberculous meningitis typically presents with clear or cloudy CSF, a slightly elevated white blood cell count (5-100 cells/”l, mostly lymphocytes), significantly elevated protein levels, and a very low CSF-to-plasma-glucose ratio. A sub-arachnoid hemorrhage, which is not meningitis, typically presents with a sudden, severe headache and signs of increased intracranial pressure. The CSF in this case often shows xanthochromia.
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This question is part of the following fields:
- Infectious Diseases
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Question 83
Correct
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Which of the following vaccines utilizes an inactive form of the virus or organism?
Your Answer: Influenza (intramuscular)
Explanation:Types of Vaccines and Their Characteristics
Vaccines are essential in preventing the spread of infectious diseases. However, it is crucial to understand the different types of vaccines and their characteristics to ensure their safety and effectiveness. Live attenuated vaccines, such as BCG, MMR, and oral polio, may pose a risk to immunocompromised patients. In contrast, inactivated preparations, including rabies and hepatitis A, are safe for everyone. Toxoid vaccines, such as tetanus, diphtheria, and pertussis, use inactivated toxins to generate an immune response. Subunit and conjugate vaccines, such as pneumococcus, haemophilus, meningococcus, hepatitis B, and human papillomavirus, use only part of the pathogen or link bacterial polysaccharide outer coats to proteins to make them more immunogenic. Influenza vaccines come in different types, including whole inactivated virus, split virion, and sub-unit. Cholera vaccine contains inactivated strains of Vibrio cholerae and recombinant B-subunit of the cholera toxin. Hepatitis B vaccine contains HBsAg adsorbed onto aluminium hydroxide adjuvant and is prepared from yeast cells using recombinant DNA technology. Understanding the different types of vaccines and their characteristics is crucial in making informed decisions about vaccination.
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This question is part of the following fields:
- Infectious Diseases
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Question 84
Incorrect
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A 32-year-old woman presents to her General Practitioner with a 4-day history of abdominal cramps and watery diarrhoea. Her symptoms started two days after she ate a salad from a restaurant.
Which of the following is the most likely causative organism?Your Answer: Rotavirus
Correct Answer: Campylobacter jejuni
Explanation:Campylobacter jejuni is a prevalent cause of bacterial food poisoning in the UK, typically transmitted through contaminated food or drink. Symptoms usually appear 2-5 days after exposure and may include abdominal cramps, diarrhea (which may or may not be bloody), nausea, vomiting, and fever. While symptoms are usually mild and self-limiting, severe cases or immunocompromised patients may require antibiotic treatment. Bacillus cereus and Clostridium perfringens are less likely causes of food poisoning due to their short incubation periods and milder symptoms. Rotavirus is a common cause of viral gastroenteritis in children, but adults are rarely affected due to immunity. Staphylococcus aureus can also cause food poisoning, with symptoms appearing 2-6 hours after ingestion and including nausea, vomiting, and abdominal pain.
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This question is part of the following fields:
- Infectious Diseases
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Question 85
Incorrect
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You are counseling a patient regarding malaria chemoprophylaxis for their upcoming trip to the coast of Kenya. The patient is a 60-year-old with fair skin and a history of psychiatric illness. The area is known for malaria with widespread chloroquine resistance, and the species of malaria found in the area include P. falciparum, P. Vivix, and P. Ovale. Based on this information, which anti-malarial medication would you suggest for this patient?
Your Answer: Mefloquine
Correct Answer: Atovaquone/Proguanil
Explanation:Malaria Chemoprophylaxis: Choosing the Right Medication
Malaria is a potentially fatal disease that requires chemoprophylaxis for individuals entering known malaria areas. Atovaquone/proguanil (Malarone) is a well-tolerated, once-daily medication that is effective in both preventing and treating malaria. It should be taken 24 hours before entering a malaria zone and continued for seven days after leaving. However, advice on bite avoidance is also crucial in preventing malaria.
Doxycycline is a cheaper alternative to atovaquone/proguanil, but it may cause nausea and photosensitivity, which can be problematic for fair-skinned individuals. Chloroquine is an inferior choice due to widespread resistance, while mefloquine (Larium) may cause psychosis, making it unsuitable for patients with a psychiatric history.
It is important to note that advising against chemoprophylaxis is not appropriate, as malaria poses a serious risk to all individuals, regardless of their previous exposure to malaria areas.
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This question is part of the following fields:
- Infectious Diseases
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Question 86
Incorrect
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A 25-year-old student taking the oral contraceptive pill develops pain and soreness around the genitals. She has just completed an elective year in the United States (USA). On examination, there are multiple, shallow and tender ulcers at the skin and mucous membrane of the vagina.
Which of the following is the most probable diagnosis?
Your Answer: Primary syphilis
Correct Answer: Genital herpes
Explanation:Sexually Transmitted Diseases: Causes and Symptoms
Sexually transmitted diseases (STDs) are infections that are spread through sexual contact. There are various types of STDs, each with its own set of symptoms and causes. Genital herpes is caused by herpes simplex viruses, with type 2 being responsible for the majority of cases. It can present as vesicular lesions around the genitals, rectum or mouth, but most individuals are asymptomatic. Granuloma inguinale is a chronic bacterial infection that results in nodular lesions that evolve into ulcers. Chancroid is a bacterial STD caused by Haemophilus ducreyi, characterised by painful necrotising genital ulcers. Primary syphilis is caused by the spirochaete Treponema pallidum, with lesions beginning as solitary, raised, firm, red papules that can be several centimetres in diameter. Lymphogranuloma venereum is an uncommon STD caused by Chlamydia trachomatis, characterised by self-limited genital papules or ulcers, followed by painful inguinal and/or femoral lymphadenopathy. Non-infectious causes include fixed drug reactions, Behçetâs disease, neoplasms and trauma. It is important to consider these alternative causes if evaluations for the infectious aetiologies do not lead to a diagnosis. HIV infection should always be considered and tested for.
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This question is part of the following fields:
- Infectious Diseases
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Question 87
Correct
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A 7-year-old boy who has recently arrived from India complains of fever. During examination, extensive cervical lymphadenopathy is observed and a grey coating is seen surrounding the tonsils. What is the probable diagnosis?
Your Answer: Diphtheria
Explanation:Understanding Diphtheria: Causes, Symptoms, and Treatment
Diphtheria is a bacterial infection caused by the Gram positive bacterium Corynebacterium diphtheriae. The pathophysiology of this disease involves the release of an exotoxin encoded by a ÎČ-prophage, which inhibits protein synthesis by catalyzing ADP-ribosylation of elongation factor EF-2. This toxin commonly causes a ‘diphtheric membrane’ on tonsils, resulting in a grey, pseudomembrane on the posterior pharyngeal wall. Systemic distribution may produce necrosis of myocardial, neural, and renal tissue.
Possible presentations of diphtheria include sore throat with a ‘diphtheric membrane’, bulky cervical lymphadenopathy, and neuritis of cranial nerves. It may also result in a ‘bull neck’ appearance and heart block. People who have recently visited Eastern Europe, Russia, or Asia are at a higher risk of contracting this disease.
To diagnose diphtheria, a culture of throat swab is taken using tellurite agar or Loeffler’s media. The treatment for diphtheria involves intramuscular penicillin and diphtheria antitoxin.
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This question is part of the following fields:
- Infectious Diseases
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Question 88
Correct
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A 16-year-old young woman is completing a summer internship at a daycare center before applying to study medicine. She has received a full schedule of childhood vaccinations. Her primary complaints are difficulty swallowing, a sore throat, malaise, and a fever. Upon examination, she has 5-10 gray ulcers on her buccal mucosa. Additionally, she has a vesicular rash on her hands and feet.
What is the most probable cause of this clinical presentation?Your Answer: Coxsackie virus infection
Explanation:Differential Diagnosis: Hand-Foot-and-Mouth Disease
Hand-foot-and-mouth disease is a viral illness caused by Coxsackie virus A type 16. It presents as a vesicular eruption in the mouth and can also involve the hands, feet, buttocks, and/or genitalia. Macular lesions on the buccal mucosa, tongue, and/or hard palate rapidly progress to vesicles that erode and become surrounded by an erythematous halo. Skin lesions, which present as tender macules or vesicles on an erythematous base, develop in approximately 75% of patients. Treatment is supportive, and there is no antiviral agent specific for the aetiological agents. Adequate fluid intake, preferably with cold drinks, is essential to prevent dehydration.
Other conditions that may present with similar symptoms include erythema multiforme, herpes simplex infection, gonorrhoea, and pemphigus erythematosus. However, the clinical presentation and causative agent of hand-foot-and-mouth disease distinguish it from these other conditions.
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This question is part of the following fields:
- Infectious Diseases
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Question 89
Correct
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You are asked to evaluate a 19-year-old student who has recently returned from a gap-year trip to India. He complains of extreme fatigue and loss of appetite during the last week of his journey and noticed that he had jaundice just before his return home. He denies being an intravenous drug user and having unprotected sexual intercourse. Additionally, he did not receive any blood transfusions or tattoos during his trip. He reports having a fever, but it subsided once his jaundice appeared. After conducting liver function tests (LFTs), you find that his alanine aminotransferase (ALT) level is 950 iu/l (reference range 20â60 iu/l), total bilirubin level is 240 ÎŒmol/l (reference range <20 ÎŒmol/l), and his alkaline phosphatase (ALP) level is slightly above the upper limit of normal. His white blood cell count, albumin level, and prothrombin times are all normal. What is the most probable diagnosis based on this clinical presentation?
Your Answer: Hepatitis A
Explanation:Overview of Viral Infections and Their Clinical Manifestations
Hepatitis A, B, and C, leptospirosis, and cytomegalovirus (CMV) are all viral infections that can cause a range of clinical manifestations. Hepatitis A is typically transmitted through ingestion of contaminated food and is most common in resource-poor regions. Leptospirosis is associated with exposure to rodents and contaminated water or soil. Hepatitis B is transmitted through blood and sexual contact, while hepatitis C is most commonly spread through injection drug use. CMV is typically asymptomatic but can cause severe disease in immunocompromised individuals. Understanding the transmission and clinical manifestations of these viral infections is important for accurate diagnosis and appropriate treatment.
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This question is part of the following fields:
- Infectious Diseases
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Question 90
Correct
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A 55-year-old rancher presents to the ER with his spouse. He is experiencing a high fever and excessive sweating. During the examination, multiple black blisters are observed, which are producing a malodorous discharge. What is the typical microorganism linked to this ailment?
Your Answer: Clostridium perfringens
Explanation:Gas gangrene is a severe bacterial infection that can lead to muscle necrosis, sepsis, gas production, and ultimately, death. The infection can occur in two ways: through traumatic or surgical inoculation of a wound with bacteria, or spontaneously, which is often observed in immunocompromised patients. While there are multiple causes of gas gangrene, clostridium perfringens, a type of clostridia species, is frequently implicated. The condition typically begins with pain and progresses to systemic symptoms such as fever and dehydration. Skin changes, including blisters that can burst and produce a foul-smelling discharge, are also common. Movement may produce a crackling sound known as crepitus.
Clostridia: Gram-Positive Anaerobic Bacilli
Clostridia are a group of gram-positive, obligate anaerobic bacilli. There are several species of Clostridia, each with their own unique features and pathologies. C. perfringens produces α-toxin, a lecithinase, which can cause gas gangrene and haemolysis. Symptoms of gas gangrene include tender, oedematous skin with haemorrhagic blebs and bullae, and crepitus may be present on palpation. C. botulinum is typically found in canned foods and honey and can cause flaccid paralysis by preventing the release of acetylcholine. C. difficile is known for causing pseudomembranous colitis, which is often seen after the use of broad-spectrum antibiotics. This species produces both an exotoxin and a cytotoxin. Finally, C. tetani produces an exotoxin called tetanospasmin, which prevents the release of glycine from Renshaw cells in the spinal cord, leading to spastic paralysis.
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This question is part of the following fields:
- Infectious Diseases
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Question 91
Correct
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A 25-year-old woman visits her doctor complaining of diarrhoea and vomiting after spending Christmas with her family. Her sister has just informed her that she too is experiencing the same symptoms. The doctor suspects norovirus. What is the best way to prevent the spread of this virus?
Your Answer: Wash hands with soap and water
Explanation:Handwashing is more effective than alcohol gels in preventing the spread of norovirus.
Norovirus, also known as the winter vomiting bug, is a common cause of gastroenteritis in the UK. It is a type of RNA virus that can cause symptoms such as nausea, vomiting, and diarrhea, as well as headaches, low-grade fevers, and myalgia. The virus is highly contagious and can be transmitted through the fecal-oral route, as well as through aerosolized particles from vomit or contaminated bodily fluids. Good hand hygiene and isolation of infected individuals are important measures to limit transmission. Diagnosis is typically made through clinical history and stool culture viral PCR. While the infection is self-limiting in most cases, dehydration and electrolyte imbalances can occur and require supportive management.
Norovirus is a genus of non-encapsulated RNA virus species that can cause gastroenteritis. The CDC estimates that 1 in 5 cases of infectious gastroenteritis are caused by norovirus, with 685 million cases per year worldwide. Symptoms typically develop within 15-50 hours of infection and can include vomiting, diarrhea, headaches, low-grade fevers, and myalgia. The virus is highly contagious and can be transmitted through direct physical contact, contact with contaminated food, or through aerosolized particles from vomit or contaminated bodily fluids. Good hand hygiene and isolation of infected individuals are important measures to limit transmission. Diagnosis is typically made through clinical history and stool culture viral PCR. While the infection is self-limiting in most cases, dehydration and electrolyte imbalances can occur and require supportive management.
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This question is part of the following fields:
- Infectious Diseases
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Question 92
Incorrect
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A 19-year-old non-pregnant, asymptomatic woman with no past medical history is found to have 106 colony-forming units of Escherichia coli/ml of urine on a routine health check.
Which of the following is the most appropriate management?
Your Answer: Treat with a single dose of oral trimethroprim
Correct Answer: No antibiotics are indicated
Explanation:Management of Asymptomatic Bacteriuria
Asymptomatic bacteriuria is a common finding in clinical practice, but it does not require antibiotic treatment. Patients with asymptomatic bacteriuria are at increased risk for symptomatic UTI, but treatment does not decrease the frequency of symptomatic UTIs nor improve other outcomes. Therefore, screening for or treatment of asymptomatic bacteriuria is not appropriate and should be discouraged.
Treatment of asymptomatic bacteriuria in women should be reserved for pregnant patients, those undergoing a urological procedure that may produce mucosal bleeding, and the significantly immunosuppressed. Pregnant patients are considered immunosuppressed UTI hosts due to the physiological changes associated with pregnancy, which increase the risk for serious complications even in healthy pregnant women. However, it should not be treated in diabetic patients, elderly individuals, or those with indwelling catheters.
Antibiotic treatment is not recommended in this clinical scenario, even in symptomatic UTIs. Current UK antimicrobial guidance recommends treatment for 3-7 days, depending on the clinical case, not with a single-dose administration. Investigating the renal tract is also not necessary for a single finding of asymptomatic bacteriuria.
Intravenous antibiotic treatment is reserved for complicated UTIs, in which case the patient would present far more unwell than what is seen in this scenario. Underlying conditions that predispose patients to complicated UTIs include diabetes, renal failure, functional or anatomic abnormality of the urinary tract, renal transplantation, an indwelling catheter stent, or immunosuppression.
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This question is part of the following fields:
- Infectious Diseases
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Question 93
Incorrect
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A 25-year-old female presented to her GP with a grey, thin, creamy vaginal discharge.
Which of the following is the best verbal advice to give her?Your Answer: Douche regularly
Correct Answer: Avoid perfumed soaps
Explanation:Bacterial Vaginosis: Symptoms, Risk Factors, and Diagnosis
Bacterial vaginosis (BV) is a common vaginal infection caused by an overgrowth of bacteria. It is important for patients to understand the symptoms, risk factors, and diagnosis of BV in order to properly manage and treat the condition.
Symptoms of BV include vaginal odor, increased vaginal discharge, vulvar irritation, and rarely, dysuria or dyspareunia. Risk factors for BV include recent antibiotic use, decreased estrogen production, presence of an intrauterine device, douching, and sexual activity that could lead to transmission.
Physical findings of BV include grey, thin, and homogeneous vaginal discharge that adheres to the vaginal mucosa, increased light reflex of the vaginal walls, and typically little or no evidence of inflammation. Diagnosis of BV is made through microscopic examination of the discharge, with demonstration of three of the following four Amsel criteria: clue cells on a saline smear, a pH >4.5, characteristic discharge, and a positive whiff test.
Patients with BV should be advised to wash only with hypoallergenic bar soaps or no soap at all, avoid liquid soaps, body washes, and perfumed soaps, and not to douche or use over-the-counter vaginal hygiene products. While studies have shown inconsistent results, some patients may find relief from symptoms by using yogurt containing live bacteria.
It is important to properly manage and treat BV, as long-standing or untreated cases may lead to more serious complications such as endometritis, salpingitis, pelvic inflammatory disease, or pregnancy complications. However, with proper care and attention, the prognosis for uncomplicated cases of BV is generally excellent.
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This question is part of the following fields:
- Infectious Diseases
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Question 94
Correct
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If you sustain a needlestick injury while taking blood from a patient suspected of having human immunodeficiency virus (HIV), what should be your first course of action?
Your Answer: Wash wound under running water, encouraging active bleeding
Explanation:Immediate Actions to Take Following a Needlestick Injury: A Guide for Healthcare Workers
Needlestick injuries are a common occupational hazard for healthcare workers. If you experience a needlestick injury, it is important to take immediate action to minimize the risk of infection. Here are the steps you should take:
1. Wash the wound thoroughly under running water, while encouraging bleeding. This will help to flush out any pathogens that may be present.
2. Determine the patient’s HIV and bloodborne disease status. If the patient is HIV-positive or deemed to be at high risk, HIV post-exposure prophylaxis (PEP) should be offered as soon as possible.
3. Begin Truvada and Kaletra PEP treatment if the patient is definitely HIV-positive or deemed to be at high risk. PEP should be commenced within 72 hours of exposure for maximum effectiveness.
4. Contact occupational health immediately to identify local protocols and receive guidance on next steps.
5. Fill out a clinical incident form to help the hospital identify potential areas for improvement in employee safety.
By following these steps, you can minimize the risk of infection and protect your health as a healthcare worker.
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This question is part of the following fields:
- Infectious Diseases
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Question 95
Incorrect
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A 67-year-old woman presents with a 2-week history of frequent loose stools, left iliac fossa discomfort and fever without rectal bleeding.
Three months ago she was treated for confirmed Clostridium difficile infection with oral vancomycin, with a resolution of symptoms.
On examination, her heart rate is 90 bpm, respiratory rate of 18 breaths/min, temperature 37.6ÂșC and blood pressure of 130/86 mmHg. Her abdomen is generally mildly tender, without guarding.
A repeat stool culture confirms Clostridium difficile infection.
What is the most appropriate treatment for this patient?Your Answer: Oral vancomycin AND IV metronidazole
Correct Answer: Oral fidaxomicin
Explanation:If a patient experiences a recurrent episode of C. difficile within 12 weeks of symptom resolution, it is recommended to treat them with oral fidaxomicin. However, the use of bezlotoxumab to prevent recurrences is not currently supported by NICE due to cost-effectiveness concerns. Faecal microbiota transplant may be considered for patients who have had two or more previous episodes, but not on the first recurrence. In cases of life-threatening Clostridium difficile infection, both oral vancomycin and IV metronidazole should be used for treatment.
Clostridioides difficile is a type of bacteria that is commonly found in hospitals. It is a Gram positive rod that produces an exotoxin which can cause damage to the intestines, leading to a condition called pseudomembranous colitis. This bacteria usually develops when the normal gut flora is suppressed by broad-spectrum antibiotics, with second and third generation cephalosporins being the leading cause of C. difficile. Other risk factors include proton pump inhibitors. Symptoms of C. difficile include diarrhea, abdominal pain, and a raised white blood cell count. The severity of the infection can be determined using the Public Health England severity scale, which ranges from mild to life-threatening.
To diagnose C. difficile, a stool sample is tested for the presence of C. difficile toxin (CDT). Treatment for a first episode of C. difficile infection typically involves oral vancomycin for 10 days, with fidaxomicin or a combination of oral vancomycin and IV metronidazole being used as second and third-line therapies. Recurrent infections occur in around 20% of patients, increasing to 50% after their second episode. In such cases, oral fidaxomicin is recommended within 12 weeks of symptom resolution, while oral vancomycin or fidaxomicin can be used after 12 weeks. For life-threatening C. difficile infections, oral vancomycin and IV metronidazole are used, and surgery may be considered with specialist advice. Other therapies, such as bezlotoxumab and fecal microbiota transplant, may also be considered for preventing recurrences in certain cases.
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This question is part of the following fields:
- Infectious Diseases
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Question 96
Correct
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An 80-year-old man presents with a 2-week history of profuse loose stools and severe abdominal pain over the past 2 days. He has lost his appetite and is only tolerating small amounts of fluid over the past 24 hours. On examination, his heart rate is 118 bpm, respiratory rate is 22 breaths/min, temperature 38.1ÂșC and blood pressure is 104/74 mmHg. Significant left iliac fossa tenderness is noted. The patient is urgently admitted, and a stool culture confirms Clostridium difficile infection and severe colitis without perforation on imaging. What is the most appropriate treatment for this patient?
Your Answer: Oral vancomycin AND IV metronidazole
Explanation:The treatment for life-threatening C. difficile infection involves administering vancomycin orally and metronidazole intravenously.
Clostridioides difficile is a type of bacteria that is commonly found in hospitals. It is a Gram positive rod that produces an exotoxin which can cause damage to the intestines, leading to a condition called pseudomembranous colitis. This bacteria usually develops when the normal gut flora is suppressed by broad-spectrum antibiotics, with second and third generation cephalosporins being the leading cause of C. difficile. Other risk factors include proton pump inhibitors. Symptoms of C. difficile include diarrhea, abdominal pain, and a raised white blood cell count. The severity of the infection can be determined using the Public Health England severity scale, which ranges from mild to life-threatening.
To diagnose C. difficile, a stool sample is tested for the presence of C. difficile toxin (CDT). Treatment for a first episode of C. difficile infection typically involves oral vancomycin for 10 days, with fidaxomicin or a combination of oral vancomycin and IV metronidazole being used as second and third-line therapies. Recurrent infections occur in around 20% of patients, increasing to 50% after their second episode. In such cases, oral fidaxomicin is recommended within 12 weeks of symptom resolution, while oral vancomycin or fidaxomicin can be used after 12 weeks. For life-threatening C. difficile infections, oral vancomycin and IV metronidazole are used, and surgery may be considered with specialist advice. Other therapies, such as bezlotoxumab and fecal microbiota transplant, may also be considered for preventing recurrences in certain cases.
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This question is part of the following fields:
- Infectious Diseases
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Question 97
Correct
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A 26-year-old man came to the clinic complaining of fevers, sore throat, and cervical lymphadenopathy that had been going on for 8 days. A positive monospot test was obtained. What is the most appropriate management plan?
Your Answer: Reassurance
Explanation:Infectious mononucleosis caused by the Epstein bar virus (EBV) is usually a self-limiting condition that lasts for approximately 2 weeks in individuals with a healthy immune system. Treatment options such as aciclovir, penicillin V, clarithromycin, and valganciclovir are not effective for treating EBV.
Understanding Infectious Mononucleosis
Infectious mononucleosis, also known as glandular fever, is a viral infection caused by the Epstein-Barr virus (EBV) in 90% of cases. It is most commonly seen in adolescents and young adults. The classic triad of symptoms includes sore throat, pyrexia, and lymphadenopathy, which are present in around 98% of patients. Other symptoms include malaise, anorexia, headache, palatal petechiae, splenomegaly, hepatitis, lymphocytosis, haemolytic anaemia, and a maculopapular rash. The symptoms typically resolve after 2-4 weeks.
The diagnosis of infectious mononucleosis is confirmed through a heterophil antibody test (Monospot test) in the second week of the illness. Management is supportive and includes rest, drinking plenty of fluids, avoiding alcohol, and taking simple analgesia for any aches or pains. It is recommended to avoid playing contact sports for 4 weeks after having glandular fever to reduce the risk of splenic rupture.
Interestingly, there is a correlation between EBV and socioeconomic groups. Lower socioeconomic groups have high rates of EBV seropositivity, having frequently acquired EBV in early childhood when the primary infection is often subclinical. However, higher socioeconomic groups show a higher incidence of infectious mononucleosis, as acquiring EBV in adolescence or early adulthood results in symptomatic disease.
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This question is part of the following fields:
- Infectious Diseases
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Question 98
Correct
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A 25-year-old student presents to his General Practitioner with a 10-day history of fever and sore throat. He recently completed a course of amoxicillin despite developing a rash a few days into the course. On examination, he is febrile and his tonsils are inflamed but no exudate is present; there are petechial spots on his palate and he has a widespread maculopapular rash, cervical lymphadenopathy and splenomegaly.
Which of the following is the most likely diagnosis?
Your Answer: Infectious mononucleosis
Explanation:Differential Diagnosis of a Patient with Sore Throat and Fever
Infectious mononucleosis, also known as glandular fever, is a common cause of sore throat and fever in adolescents. It is caused by the Epstein-Barr virus and presents with symptoms such as sore throat, fever, and lethargy. The duration of symptoms is longer than other causes of acute sore throat, and examination findings may include lymphadenopathy and splenomegaly. Palatal petechiae is a distinguishing feature between glandular fever and streptococcal tonsillitis. A maculopapular rash may also be present, but it is important to note that amoxicillin can cause a rash in patients with glandular fever. Stevens-Johnson syndrome, bacterial tonsillitis, candidiasis, and mumps are other possible differential diagnoses. However, Stevens-Johnson syndrome is a severe mucocutaneous reaction to medications or infections, bacterial tonsillitis presents with enlarged, inflamed tonsils with exudate and cervical lymphadenopathy, candidiasis presents with white coating of buccal membranes, throat, or tongue, and mumps presents with bilateral parotid gland enlargement. Therefore, based on the patient’s history and examination findings, infectious mononucleosis is the most likely diagnosis.
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This question is part of the following fields:
- Infectious Diseases
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Question 99
Incorrect
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A 32-year-old female sex worker presents to the emergency department complaining of a high fever and severe headache. During the physical examination, you observe neck stiffness and mild photophobia, prompting you to perform a lumbar puncture. The results of the lumbar puncture reveal the presence of a yeast and a capsule in the CSF stained with India ink.
What is the most probable diagnosis?Your Answer: Aspergillus abscess
Correct Answer: Cryptococcal meningitis
Explanation:Cryptococcus neoformans is a yeast that has a protective capsule and requires oxygen to survive. It can thrive in both plants and animals, and when it infects humans, it causes cryptococcosis. While the infection typically affects the lungs, it can also lead to fungal meningitis and encephalitis in individuals with weakened immune systems. HIV-positive patients are particularly susceptible to this infection, and given the patient’s history as a sex worker, it’s possible that they have an undiagnosed HIV infection that has progressed to AIDS. Additionally, cryptococcus neoformans can be detected through india ink staining during a lumbar puncture.
The investigation and management of suspected bacterial meningitis are intertwined due to the potential negative impact of delayed antibiotic treatment. Patients should be urgently transferred to the hospital, and an ABC approach should be taken initially. A lumbar puncture should be delayed in certain circumstances, and IV antibiotics should be given as a priority if there is any doubt. The bloods and CSF should be tested for various parameters, and prophylaxis should be offered to households and close contacts of patients affected with meningococcal meningitis.
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This question is part of the following fields:
- Infectious Diseases
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Question 100
Correct
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A 28-year-old woman complains of a yellowish-green vaginal discharge that began two weeks ago. During examination, her vagina appears swollen and red.
What is the most probable diagnosis?Your Answer: Trichomoniasis
Explanation:Common Genitourinary Infections: Symptoms and Diagnosis
Trichomoniasis, Candidiasis, AIDS, HPV, and Lactobacilli infection are some of the most common genitourinary infections. Trichomoniasis is caused by Trichomonas vaginalis and presents with abnormal vaginal discharge, odour, itching, burning, soreness, and dyspareunia. Candidiasis is a fungal infection caused by yeasts from the genus Candida and presents with pruritus, vaginal discharge, dysuria, and dyspareunia. AIDS is a viral infection that has a hyperacute onset and is unlikely in patients with no past medical history or risk factors. HPV infection is common and often goes unnoticed, but can manifest as warty lesions on the genital or anal area. Lactobacilli infection is not associated with causing infection. Diagnosis of these infections depends on laboratory testing, with culture being the current criterion standard for trichomoniasis and physical examination for candidiasis.
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This question is part of the following fields:
- Infectious Diseases
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Question 101
Correct
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A 50-year-old man residing in the UK has been diagnosed with pulmonary tuberculosis and his sputum test is positive for acid-fast bacilli. He has a medical history of hypertension and takes bendroflumethiazide and amlodipine. What is the recommended initial medication combination for him?
Your Answer: Rifampicin, isoniazid, pyrazinamide and ethambutol
Explanation:Managing Tuberculosis: Treatment and Complications
Tuberculosis is a serious infectious disease that requires prompt and effective treatment. The standard therapy for active tuberculosis involves an initial phase of two months, during which patients are given a combination of four drugs: rifampicin, isoniazid, pyrazinamide, and ethambutol. The continuation phase lasts for four months and involves the use of rifampicin and isoniazid. Patients with latent tuberculosis are typically treated with a combination of isoniazid and rifampicin for three or six months, depending on the severity of the infection.
In some cases, patients may require prolonged treatment, particularly if they have meningeal tuberculosis. Steroids may be added to the treatment regimen in these cases. Directly observed therapy may also be necessary for certain groups, such as homeless individuals, prisoners, and patients who are likely to have poor concordance.
While tuberculosis treatment is generally effective, there are some potential complications to be aware of. Immune reconstitution disease can occur several weeks after starting treatment and may present with enlarging lymph nodes. Drug adverse effects are also possible, with rifampicin being a potent liver enzyme inducer and isoniazid causing peripheral neuropathy. Pyrazinamide can cause hyperuricaemia and ethambutol may lead to optic neuritis, so it is important to monitor patients closely for any signs of adverse effects. Overall, with proper management and monitoring, tuberculosis can be successfully treated.
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This question is part of the following fields:
- Infectious Diseases
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Question 102
Correct
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A 32-year-old man comes to the clinic with a maculopapular rash and mouth ulcers. He had a painless penile ulcer two months ago. What is the most probable causative organism for his symptoms?
Your Answer: Treponema pallidum
Explanation:The symptoms exhibited by this individual suggest the presence of secondary syphilis.
Understanding Syphilis: Symptoms and Stages
Syphilis is a sexually transmitted infection caused by the bacterium Treponema pallidum. The infection progresses through three stages: primary, secondary, and tertiary. The incubation period can range from 9 to 90 days.
During the primary stage, a painless ulcer called a chancre appears at the site of sexual contact. Local lymph nodes may also become swollen, but this symptom may not be visible in women if the lesion is on the cervix.
The secondary stage occurs 6 to 10 weeks after the primary infection and is characterized by systemic symptoms such as fevers and lymphadenopathy. A rash may appear on the trunk, palms, and soles, along with buccal ulcers and painless warty lesions on the genitalia.
In the tertiary stage, granulomatous lesions called gummas may develop on the skin and bones, and there may be an ascending aortic aneurysm. Other symptoms include general paralysis of the insane, tabes dorsalis, and Argyll-Robertson pupil.
Congenital syphilis can also occur if a pregnant woman is infected. Symptoms include blunted upper incisor teeth, linear scars at the angle of the mouth, keratitis, saber shins, saddle nose, and deafness.
Understanding the symptoms and stages of syphilis is important for early detection and treatment. It is a treatable infection, but if left untreated, it can lead to serious complications.
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This question is part of the following fields:
- Infectious Diseases
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Question 103
Correct
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A 15-year-old girl comes to the emergency department complaining of a maculopapular rash that has been present for 1 day. She had visited her family doctor 2 days ago with symptoms of a cold and a sore throat and was given a course of oral antibiotics. Upon examination, she has a mild fever of 37.8ÂșC and a widespread maculopapular rash on her face and torso. Her tonsils are enlarged and erythematous, and she has palpable tender posterior cervical lymphadenopathy. What is the most appropriate diagnostic test to identify the underlying condition?
Your Answer: Monospot test
Explanation:The patient in question is likely suffering from glandular fever, a viral illness caused by the Ebstein-Barr virus. Symptoms include a sore throat, fever, and general malaise, as well as palpable cervical lymphadenopathy and an erythematous throat. The illness is more common in teenagers and is often spread through respiratory droplets, earning it the nickname kissing disease. The patient was prescribed amoxicillin by their GP, which can cause a non-specific maculopapular rash in patients with glandular fever. The diagnosis is typically confirmed through a Monospot blood test, which detects the presence of heterophil antibodies produced in response to the virus.
An anti-streptolysin O titre test can detect streptococcal infections, but it does not explain the patient’s rash following antibiotic use. A full blood count can be helpful in diagnosing glandular fever, as it often shows a lymphocytosis, but the Monospot test is more definitive. A nasopharyngeal aspirate for viral PCR can diagnose viral infections like measles, but this is less likely in a teenager in the UK due to vaccination. A sputum culture is not useful in diagnosing glandular fever, as the patient does not have a cough or sputum production.
Understanding Infectious Mononucleosis
Infectious mononucleosis, also known as glandular fever, is a viral infection caused by the Epstein-Barr virus (EBV) in 90% of cases. It is most commonly seen in adolescents and young adults. The classic triad of symptoms includes sore throat, pyrexia, and lymphadenopathy, which are present in around 98% of patients. Other symptoms include malaise, anorexia, headache, palatal petechiae, splenomegaly, hepatitis, lymphocytosis, haemolytic anaemia, and a maculopapular rash. The symptoms typically resolve after 2-4 weeks.
The diagnosis of infectious mononucleosis is confirmed through a heterophil antibody test (Monospot test) in the second week of the illness. Management is supportive and includes rest, drinking plenty of fluids, avoiding alcohol, and taking simple analgesia for any aches or pains. It is recommended to avoid playing contact sports for 4 weeks after having glandular fever to reduce the risk of splenic rupture.
Interestingly, there is a correlation between EBV and socioeconomic groups. Lower socioeconomic groups have high rates of EBV seropositivity, having frequently acquired EBV in early childhood when the primary infection is often subclinical. However, higher socioeconomic groups show a higher incidence of infectious mononucleosis, as acquiring EBV in adolescence or early adulthood results in symptomatic disease.
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This question is part of the following fields:
- Infectious Diseases
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Question 104
Incorrect
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A 26-year-old patient visits the GP clinic seeking a sexual health examination. He engages in sexual activity with men and practices unprotected anal intercourse as both the insertive and receptive partner. He has never undergone any HIV testing and desires a prompt result. What is the most suitable test to request for this patient?
Your Answer: HIV viral load and HIV antibody test
Correct Answer: HIV p24 antigen and HIV antibody test
Explanation:The current standard for HIV diagnosis and screening involves a combination of p24 antigen and HIV antibody tests. This is because the HIV antibody may not be detectable until 4-6 weeks after infection, while the p24 antigen can show up as early as 1 week after infection. By using both tests, a more accurate assessment of infectious status can be made, allowing for discussions about pre-exposure prophylaxis and safe sexual practices. HIV viral load levels are not used for diagnosis, but can be helpful in assessing treatment efficacy after diagnosis has been confirmed. It is important to note that viral load testing should not be used alone, but rather in conjunction with the antibody and antigen tests.
Understanding HIV Seroconversion and Diagnosis
HIV seroconversion is a process where the body develops antibodies to the HIV virus after being infected. This process is symptomatic in 60-80% of patients and usually presents as a glandular fever type illness. Symptoms may include sore throat, lymphadenopathy, malaise, myalgia, arthralgia, diarrhea, maculopapular rash, mouth ulcers, and rarely meningoencephalitis. The severity of symptoms is associated with a poorer long-term prognosis and typically occurs 3-12 weeks after infection.
Diagnosing HIV involves testing for HIV antibodies, which may not be present in early infection. However, most people develop antibodies to HIV at 4-6 weeks, and 99% do so by 3 months. The diagnosis usually consists of both a screening ELISA test and a confirmatory Western Blot Assay. Additionally, a p24 antigen test may be used to detect a viral core protein that appears early in the blood as the viral RNA levels rise. Combination tests that test for both HIV p24 antigen and HIV antibody are now standard for the diagnosis and screening of HIV. If the combined test is positive, it should be repeated to confirm the diagnosis. Testing for HIV in asymptomatic patients should be done at 4 weeks after possible exposure, and after an initial negative result, a repeat test should be offered at 12 weeks.
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This question is part of the following fields:
- Infectious Diseases
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Question 105
Incorrect
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You are taking the history of an Emergency Department patient who was assaulted. The victim is a 20-year-old female who has a deep laceration on her thigh caused by a rusty machete. The wound has exposed tendon, muscle, and subcutaneous fat. According to her medical records, she received all her childhood immunizations on schedule, including 5 doses of tetanus vaccine, with the last one administered when she was 16 years old.
What is the appropriate management for tetanus risk in this patient?Your Answer: Tetanus vaccine booster and tetanus immunoglobulin administration
Correct Answer: No tetanus vaccine booster and no immunoglobulins required
Explanation:If a patient has received 5 doses of the tetanus vaccine, with the most recent dose administered less than 10 years ago, they do not need a booster vaccine or immunoglobulins, regardless of the severity of the wound. This is the correct course of action. The patient’s childhood vaccinations would have included 5 doses of the tetanus vaccine, with the last dose given at age 14 or later. Therefore, the patient is already adequately protected and does not require a booster or immunoglobulin, regardless of the severity of the wound.
The option of administering a tetanus vaccine booster with antibiotics is not the correct course of action. While antibiotics may be considered for protection against other bacteria, the patient already has sufficient protection against tetanus and does not require vaccination.
Similarly, administering a tetanus vaccine booster with tetanus immunoglobulin is not necessary. As previously mentioned, the patient already has adequate protection from previous vaccinations. Immunoglobulin would only be necessary if the patient had an incomplete or unknown vaccine history or if it had been more than 10 years since the last vaccine.
Lastly, administering a tetanus vaccine booster alone is not necessary. The patient already has protection from previous vaccinations and does not require a booster.
Tetanus Vaccination and Management of Wounds
The tetanus vaccine is a purified toxin that is given as part of a combined vaccine. In the UK, it is given as part of the routine immunisation schedule at 2, 3, and 4 months, 3-5 years, and 13-18 years, providing a total of 5 doses for long-term protection against tetanus.
When managing wounds, the first step is to classify them as clean, tetanus-prone, or high-risk tetanus-prone. Clean wounds are less than 6 hours old and have negligible tissue damage, while tetanus-prone wounds include puncture-type injuries acquired in a contaminated environment or wounds containing foreign bodies. High-risk tetanus-prone wounds include wounds or burns with systemic sepsis, certain animal bites and scratches, heavy contamination with material likely to contain tetanus spores, wounds or burns with extensive devitalised tissue, and wounds or burns that require surgical intervention.
If the patient has had a full course of tetanus vaccines with the last dose less than 10 years ago, no vaccine or tetanus immunoglobulin is required regardless of the wound severity. If the patient has had a full course of tetanus vaccines with the last dose more than 10 years ago, a reinforcing dose of vaccine is required for tetanus-prone wounds, and a reinforcing dose of vaccine plus tetanus immunoglobulin is required for high-risk wounds. If the vaccination history is incomplete or unknown, a reinforcing dose of vaccine is required regardless of the wound severity, and a reinforcing dose of vaccine plus tetanus immunoglobulin is required for tetanus-prone and high-risk wounds.
Overall, proper vaccination and wound management are crucial in preventing tetanus infecti
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