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Question 1
Incorrect
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A 50-year-old woman presents with a prolonged period of feeling unwell and is diagnosed with subacute bacterial endocarditis. She had a history of rheumatic fever during childhood.
Which of the following clinical signs is not typically reported in this condition?Your Answer: Roth spots
Correct Answer: Spider naevi
Explanation:Symptoms of Subacute Bacterial Endocarditis
Subacute bacterial endocarditis is a condition that typically manifests after a prolonged period of feeling unwell. The symptoms of this condition are varied and can include Janeway lesions, Osler nodes, Roth spots, splinter hemorrhages, petechiae, finger clubbing, and microscopic hematuria. Finger clubbing is also a symptom of other cardiac conditions such as cyanotic congenital cardiac disease and atrial myxoma.
Janeway lesions are painless, small, red spots that appear on the palms and soles of the feet. Osler nodes are painful, red nodules that appear on the fingers and toes. Roth spots are small, white spots that appear on the retina of the eye. Splinter hemorrhages are small, red or brown lines that appear under the nails. Petechiae are small, red or purple spots that appear on the skin. Finger clubbing is a condition in which the fingers become enlarged and the nails curve around the fingertips. Microscopic hematuria is the presence of blood in the urine that can only be detected under a microscope.
In conclusion, subacute bacterial endocarditis can present with a range of symptoms that can be easily confused with other cardiac conditions. It is important to seek medical attention if any of these symptoms are present, especially if they persist or worsen over time.
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This question is part of the following fields:
- Infectious Diseases
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Question 2
Incorrect
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A surprised 25-year-old woman is brought to the emergency room with a possible diagnosis of Staphylococcus aureus toxic shock syndrome. What is one of the parameters used to diagnose systemic inflammatory response syndrome (SIRS)?
Your Answer: Hourly urine output
Correct Answer: White blood cell count
Explanation:Systemic Inflammatory Response Syndrome
Systemic inflammatory response syndrome (SIRS) is a condition that is diagnosed when a combination of abnormal parameters are detected. These parameters can be deranged for various reasons, including both infective and non-infective causes. Some examples of infective causes include Staph. aureus toxic shock syndrome, while acute pancreatitis is an example of a non-infective cause. The diagnosis of SIRS is based on the presence of a constellation of abnormal parameters, which include a temperature below 36°C or above 38.3°C, a heart rate exceeding 90 beats per minute, a respiratory rate exceeding 20 breaths per minute, and a white blood cell count below 4 or above 12 ×109/L.
It is important to note that the systolic blood pressure is not included in the definition of SIRS. However, if the systolic pressure remains below 90 mmHg after a fluid bolus, this would be considered a result of septic shock. the criteria for SIRS is crucial for healthcare professionals to identify and manage patients with this condition promptly.
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This question is part of the following fields:
- Infectious Diseases
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Question 3
Incorrect
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A 45-year-old engineer who recently returned from working in the Nigerian oil industry is experiencing a persistent flu-like illness, cough, unintended weight loss of 5 kilograms in 3 months, and a faint erythematous rash. During examination, enlarged cervical lymph nodes were observed. What is the most probable cause of his illness?
Your Answer: Legionnaires disease
Correct Answer: HIV seroconversion illness
Explanation:HIV Consideration for Patients Returning from Developing Countries
Patients who have recently returned from developing countries, particularly sub-Saharan Africa, should always be considered for HIV infection. This is especially important if they are exhibiting symptoms of seroconversion, which is the period when the body is producing antibodies to fight the virus. It is crucial to consider HIV as a potential diagnosis in these cases, as early detection and treatment can greatly improve outcomes. A study published in the BMJ recommends that healthcare providers keep HIV in mind when evaluating patients who have recently traveled to developing countries. By doing so, they can help prevent the spread of the virus and provide appropriate care to those who are infected. It is important to note that HIV can be asymptomatic for years, so routine testing is also recommended for individuals who have traveled to high-risk areas.
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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 22-year-old individual is brought to the medical team on call due to fever, neck stiffness, and altered Glasgow coma scale. The medical team suspects acute bacterial meningitis.
What would be the most suitable antibiotic option for this patient?Your Answer: Ciprofloxacin
Correct Answer: Cefotaxime
Explanation:Empirical Antibiotic Treatment for Acute Bacterial Meningitis
Patients aged 16-50 years presenting with acute bacterial meningitis are most likely infected with Neisseria meningitidis or Streptococcus pneumoniae. The most appropriate empirical antibiotic choice for this age group is cefotaxime alone. However, if the patient has been outside the UK recently or has had multiple courses of antibiotics in the last 3 months, vancomycin may be added due to the increase in penicillin-resistant pneumococci worldwide.
For infants over 3 months old up to adults of 50 years old, cefotaxime is the preferred antibiotic. If the patient is under 3 months or over 50 years old, amoxicillin is added to cover for Listeria monocytogenes meningitis, although this is rare. Ceftriaxone can be used instead of cefotaxime.
Once the results of culture and sensitivity are available, the antibiotic choice can be modified for optimal treatment. Benzylpenicillin is usually first line, but it is not an option in this case. It is important to choose the appropriate antibiotic treatment to ensure the best possible outcome for the patient.
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This question is part of the following fields:
- Infectious Diseases
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Question 5
Incorrect
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What is the name of the bacteriostatic antibiotic commonly used for treating 'atypical' pneumonia?
Your Answer: Gentamicin
Correct Answer: Azithromycin
Explanation:Antibiotics for Atypical Pneumonia
Atypical pneumonia refers to infections caused by mycoplasma and chlamydia bacteria. Macrolide antibiotics such as erythromycin, azithromycin, and clarithromycin are effective against these organisms as well as other upper respiratory pathogens like Haemophilus and Streptococcus. They are a good alternative for treating respiratory infections in patients allergic to penicillin. Azithromycin is particularly convenient as it only needs to be taken once a day.
Amoxicillin is effective against Streptococcus and Haemophilus but not mycoplasma and chlamydia. Cefalexin is a cephalosporin antibiotic that has broad coverage against both Gram-positive and Gram-negative bacteria, but it is not as effective against mycoplasma and chlamydia as macrolides. Gentamicin is an aminoglycoside antibiotic that is used to treat aerobic Gram-negative organisms by inhibiting mRNA. However, it can cause side effects such as nephrotoxicity, ototoxicity, and teratogenicity. Quinupristin/dalfopristin are streptogramins that inhibit the 50s subunit of ribosomes and are only used in severe infections.
In summary, macrolides are a good choice for treating atypical pneumonia, especially in patients allergic to penicillin. Other antibiotics like amoxicillin, cefalexin, and gentamicin may be effective against other respiratory pathogens but are not as effective against mycoplasma and chlamydia. Quinupristin/dalfopristin are reserved for severe infections.
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This question is part of the following fields:
- Infectious Diseases
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Question 6
Incorrect
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A 25-year-old male presents with a recent onset of vomiting and diarrhoea. Upon further inquiry, he reports consuming undercooked meat at a barbecue three days ago. What is the probable pathological mechanism responsible for his diarrhoea?
Your Answer: Increased bacterium concentration in intestinal lumen inducing osmosis into large bowel
Correct Answer: Endotoxins stimulating secretion of electrolytes into intestinal lumen
Explanation:Two Main Pathological Processes that Cause Diarrhoea
There are two main pathological processes that typically cause diarrhoea: secretory diarrhoea and osmotic diarrhoea. Secretory diarrhoea is often caused by bacteria such as E. coli and V. cholerae, which produce A-B type endotoxins that activate and increase cyclic AMP. This leads to an increase in the amounts of Na+, K+, bicarbonate, and nutrients into the apical side of the lumen, which in turn draws water into the lumen as well. On the other hand, osmotic diarrhoea occurs when osmotically active nutrients within the lumen pull water in through osmotic gradients. This is often seen in patients with pancreatic insufficiency or coeliac disease.
Laxatives work in the same manner as osmotic diarrhoea, as they increase the water content in the large bowel by exerting osmotic effects. However, in this case, laxative use is unlikely as it does not fit with the clinical history. It is important to note that diarrhoea is defined as 200 ml of water per daily excrement. the underlying pathological processes that cause diarrhoea can help in the diagnosis and treatment of this common condition.
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This question is part of the following fields:
- Infectious Diseases
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Question 7
Correct
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A previously healthy 30-year-old man has returned from a trip to Spain where he used spa pools. He is now experiencing a cough, fever, and flu-like symptoms for the past 10 days. What is the probable cause of his illness?
Your Answer: Legionella pneumophila
Explanation:Causes and Transmission of Legionella Infection
In a healthy individual, infection can be caused by a virulent organism such as Legionella pneumophila, which can lead to atypical pneumonia. However, Legionella can also cause a less severe flu-like illness known as Pontiac fever. influenzae A is another possibility, but it typically lasts for only four to five days and is not associated with water facilities. TB is unlikely, as it rarely presents with flu-like symptoms. Streptococcus pneumoniae is a form of typical pneumonia that is less likely to occur in a fit and healthy young man, while Staphylococcus aureus pneumonia is usually acquired in a hospital setting.
Legionella is transmitted through inhalation of aerosols from contaminated water sources, such as spa pools. The bacteria thrives in water temperatures between 20°C and 40°C. It is important to note that Legionella is a notifiable disease, and clinicians should inform Public Health England (previously the Health Protection Agency) in their locality when a case is diagnosed. By the causes and transmission of Legionella infection, individuals can take steps to prevent its spread and protect their health.
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This question is part of the following fields:
- Infectious Diseases
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Question 8
Correct
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A 25-year-old male has come to the clinic complaining of a low-grade fever and a small, painless lesion on his penis that is red and raw. He also has inguinal lymphadenopathy. He admits to having unprotected vaginal sex while on vacation four weeks ago. What is the probable diagnosis?
Your Answer: Primary syphilis
Explanation:Syphilis and its Symptoms
Syphilis is a sexually transmitted infection caused by Treponema pallidum. The primary stage of syphilis is characterized by a painless chancre that appears three to six weeks after contact. This ulcer is highly infectious and continuously sheds motile spirochetes. After six weeks, the lesion may resolve, leading the patient to believe they are cured. However, without treatment, the spirochaete remains in the body and can lead to secondary syphilis.
It is important to note that painful genital ulcers are typically caused by herpes simplex virus and H. ducreyi, while painless ulcers are caused by T. pallidum and Chlamydia trachomatis. HPV, on the other hand, typically causes genital warts, with strains six and 11 causing warts and strains 16 and 18 being associated with cervical cancer.
Secondary syphilis is a disseminated disease that can cause a maculopapular rash, which may involve the palms and soles. This rash is known as keratoderma blennorrhagicum (KB) and can sometimes present in patients with reactive arthritis. Additionally, patients with secondary syphilis may present with condylomata lata, which are white fleshy lesions on the genitals and signify the most infectious stage.
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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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What viral infection can cause small grey lesions on the inside of the cheek?
Your Answer: Infectious mononucleosis
Correct Answer: Measles
Explanation:Common Viral Infections and Their Clinical Manifestations
Measles, caused by the RNA paramyxovirus, is a highly contagious viral infection that spreads through air-borne droplets. Immunisation strategies have been introduced to reduce its incidence in the developed world. The vaccine is given to children between 12 and 18 months of age. Measles has two distinct phases – the infectious phase and the non-infectious phase. The infectious phase is characterised by fever, cough, conjunctivitis, and koplik’s spots. The non-infectious phase is characterised by a maculopapular rash that becomes blotchy. Complications of measles include subacute sclerosing panencephalitis, which is rare but serious.
Herpes varicella virus infection causes chickenpox, a mild childhood illness characterised by fever, headache, and malaise. A rash develops on the face and trunk. The virus remains dormant for many years after which reactivation causes shingles.
Infectious mononucleosis is caused by Epstein-Barr virus and can be asymptomatic. If symptoms occur, the infection presents with a headache, sore throat, fever, and a transient macular rash.
Mumps presents with a headache, fever, malaise, and parotid gland swelling, while symptoms of Rubella include fever, malaise, and lymphadenopathy. the clinical manifestations of these common viral infections is crucial for their timely diagnosis and management.
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This question is part of the following fields:
- Infectious Diseases
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Question 10
Incorrect
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A 20-year-old female patient complains of fever and a sore throat that has been bothering her for two days. During the examination, the doctor notes that she has a temperature of 39°C, red fauces, cervical lymphadenopathy, and a slightly palpable spleen. What investigation would be most suitable for this patient?
Your Answer: Blood cultures
Correct Answer: Monospot test
Explanation:Diagnosis of Glandular Fever with Monospot Test
Glandular fever, caused by the Epstein-Barr virus, is suspected in a young girl based on her atypical lymphocytes in a full blood count. To confirm the diagnosis, a Monospot test is used. This test detects heterophile antibodies that are produced in response to an EBV infection. The antibodies are directed against horse red blood cells, and their presence in the blood indicates an active EBV infection. The Monospot test is a quick and reliable way to diagnose glandular fever, allowing for prompt treatment and management of symptoms.
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This question is part of the following fields:
- Infectious Diseases
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