Typhoid fever is a bacterial infection caused by Salmonella typhi. Paratyphoid fever, on the other hand, is a similar illness caused by Salmonella paratyphi. Together, these two conditions are collectively known as the enteric fevers.

Typhoid fever is prevalent in India and many other parts of Asia, Africa, Central America, and South America. It is primarily transmitted through the consumption of contaminated food or water that has been infected by the feces of an acutely infected or recovering person, or a chronic carrier. About 1-6% of individuals infected with S. typhi become chronic carriers. The incubation period for this illness ranges from 7 to 21 days.

During the first week of the illness, patients experience weakness and lethargy, accompanied by a gradually increasing fever. The onset of the illness is usually subtle, and constipation is more common than diarrhea in the early stages. Other early symptoms include headaches, abdominal pain, and nosebleeds. In cases of typhoid fever, the fever can occur with a relatively slow heart rate, known as Faget’s sign.

As the illness progresses into the second week, patients often become too fatigued to get out of bed. Diarrhea becomes more prominent, the fever intensifies, and patients may become agitated and delirious. The abdomen may become tender and swollen, and approximately 75% of patients develop an enlarged spleen. In up to a third of patients, red macules known as Rose spots may appear.

In the third week, the illness can lead to various complications. Intestinal bleeding may occur due to bleeding in congested Peyer’s patches. Other potential complications include intestinal perforation, secondary pneumonia, encephalitis, myocarditis, metastatic abscesses, and septic shock.

After the third week, surviving patients begin to show signs of improvement, with the fever and symptoms gradually subsiding over the course of 7-14 days. Untreated patients have a mortality rate of 15-30%. Traditionally, drugs like ampicillin and trimethoprim have been used for treatment. However, due to the emergence of multidrug resistant cases, azithromycin or fluoroquinolones are now the primary treatment options.

Public Health England (PHE) has a primary goal of swiftly identifying potential disease outbreaks and epidemics. While accuracy of diagnosis is important, it takes a backseat to the speed of detection. Since 1968, the clinical suspicion of a notifiable infection has been sufficient for reporting purposes.

Registered medical practitioners (RMPs) are legally obligated to notify the designated proper officer at their local council or local health protection team (HPT) when they suspect cases of certain infectious diseases.

The Health Protection (Notification) Regulations 2010 specify the diseases that RMPs must report to the proper officers. These diseases include acute encephalitis, acute infectious hepatitis, acute meningitis, acute poliomyelitis, anthrax, botulism, brucellosis, cholera, COVID-19, diphtheria, enteric fever (typhoid or paratyphoid fever), food poisoning, haemolytic uraemic syndrome (HUS), infectious bloody diarrhoea, invasive group A streptococcal disease, Legionnaires’ disease, leprosy, malaria, measles, meningococcal septicaemia, mumps, plague, rabies, rubella, severe acute respiratory syndrome (SARS), scarlet fever, smallpox, tetanus, tuberculosis, typhus, viral haemorrhagic fever (VHF), whooping cough, and yellow fever.

It is worth noting that influenza is not considered a notifiable disease, making it the least likely option among the diseases listed above.

Schistosomiasis, also known as bilharzia, is a tropical disease caused by parasitic trematodes (flukes) of the Schistosoma type. The transmission of this disease occurs when water becomes contaminated with faeces or urine containing eggs, and a specific freshwater snail serves as the intermediate host. Human contact with water inhabited by the intermediate host snail is necessary for transmission to occur.

There are five species of Schistosoma that can cause human disease, namely S. japonicum, S. mansoni, S. haematobium, S. intercalatum, and S. mekongi. Schistosomiasis is the second most impactful tropical disease in terms of public health, following malaria, with over 200 million people worldwide being infected. It is prevalent in the Middle East, Africa, and parts of South America and the Caribbean. Infection can manifest as either acute or chronic.

Acute schistosomiasis is characterized by the early clinical sign of swimmers itch, which involves the development of blisters and an urticarial response at the site where the Schistosoma parasite enters the skin. This typically occurs a few days after the parasite has penetrated the skin. While most acute infections are asymptomatic, some individuals may experience an acute syndrome.

The most common acute syndrome is known as Katayama fever, which primarily affects children or young adults with no previous exposure to the disease. It is caused by an allergic reaction to the sudden release of highly antigenic eggs and usually occurs a few weeks after initial exposure to S. japonicum. Symptoms of Katayama fever include fever, flu-like illness, arthralgia, myalgia, abdominal pain, diarrhea, and cough. Patients may also exhibit right upper quadrant tenderness and hepatosplenomegaly. An extremely high eosinophil count is often present.

Chronic schistosomiasis can manifest in two major forms: intestinal and urogenital. Intestinal schistosomiasis is primarily caused by S. japonicum and S. mansoni, while S. haematobium is the main cause of urogenital schistosomiasis. In intestinal schistosomiasis, adult worms migrate from the liver to the mesenteric venules, where female worms continuously lay eggs. Common symptoms include abdominal pain and bloody diarrhea.

Infective endocarditis is a condition that can be identified by certain signs, although none of them are definitive proof of the disease. The most reliable indicators are the presence of a heart murmur and a fever. However, there are other signs that are commonly associated with infective endocarditis, including splinter hemorrhages, Osler’s nodes, Janeway lesions, and Roth spots. It is important to note that these signs can also appear in other conditions, and they are not always present in patients with infective endocarditis. In fact, each of these signs is typically found in less than a third of patients diagnosed with the disease.

Further Reading:

Infective endocarditis (IE) is an infection that affects the innermost layer of the heart, known as the endocardium. It is most commonly caused by bacteria, although it can also be caused by fungi or viruses. IE can be classified as acute, subacute, or chronic depending on the duration of illness. Risk factors for IE include IV drug use, valvular heart disease, prosthetic valves, structural congenital heart disease, previous episodes of IE, hypertrophic cardiomyopathy, immune suppression, chronic inflammatory conditions, and poor dental hygiene.

The epidemiology of IE has changed in recent years, with Staphylococcus aureus now being the most common causative organism in most industrialized countries. Other common organisms include coagulase-negative staphylococci, streptococci, and enterococci. The distribution of causative organisms varies depending on whether the patient has a native valve, prosthetic valve, or is an IV drug user.

Clinical features of IE include fever, heart murmurs (most commonly aortic regurgitation), non-specific constitutional symptoms, petechiae, splinter hemorrhages, Osler’s nodes, Janeway’s lesions, Roth’s spots, arthritis, splenomegaly, meningism/meningitis, stroke symptoms, and pleuritic pain.

The diagnosis of IE is based on the modified Duke criteria, which require the presence of certain major and minor criteria. Major criteria include positive blood cultures with typical microorganisms and positive echocardiogram findings. Minor criteria include fever, vascular phenomena, immunological phenomena, and microbiological phenomena. Blood culture and echocardiography are key tests for diagnosing IE.

In summary, infective endocarditis is an infection of the innermost layer of the heart that is most commonly caused by bacteria. It can be classified as acute, subacute, or chronic and can be caused by a variety of risk factors. Staphylococcus aureus is now the most common causative organism in most industrialized countries. Clinical features include fever, heart murmurs, and various other symptoms. The diagnosis is based on the modified Duke criteria, which require the presence of certain major and minor criteria. Blood culture and echocardiography are important tests for diagnosing IE.

In cases of acute glandular fever, certain antibiotics like ampicillin and amoxicillin can potentially cause severe rashes that affect the entire body and specifically the extremities. The exact cause of these rashes is still unknown. If there is uncertainty in the diagnosis and the clinician wants to cover the possibility of streptococcal tonsillitis, it is recommended to use phenoxymethylpenicillin (penicillin V) as the preferred treatment.

Further Reading:

Glandular fever, also known as infectious mononucleosis or mono, is a clinical syndrome characterized by symptoms such as sore throat, fever, and swollen lymph nodes. It is primarily caused by the Epstein-Barr virus (EBV), with other viruses and infections accounting for the remaining cases. Glandular fever is transmitted through infected saliva and primarily affects adolescents and young adults. The incubation period is 4-8 weeks.

The majority of EBV infections are asymptomatic, with over 95% of adults worldwide having evidence of prior infection. Clinical features of glandular fever include fever, sore throat, exudative tonsillitis, lymphadenopathy, and prodromal symptoms such as fatigue and headache. Splenomegaly (enlarged spleen) and hepatomegaly (enlarged liver) may also be present, and a non-pruritic macular rash can sometimes occur.

Glandular fever can lead to complications such as splenic rupture, which increases the risk of rupture in the spleen. Approximately 50% of splenic ruptures associated with glandular fever are spontaneous, while the other 50% follow trauma. Diagnosis of glandular fever involves various investigations, including viral serology for EBV, monospot test, and liver function tests. Additional serology tests may be conducted if EBV testing is negative.

Management of glandular fever involves supportive care and symptomatic relief with simple analgesia. Antiviral medication has not been shown to be beneficial. It is important to identify patients at risk of serious complications, such as airway obstruction, splenic rupture, and dehydration, and provide appropriate management. Patients can be advised to return to normal activities as soon as possible, avoiding heavy lifting and contact sports for the first month to reduce the risk of splenic rupture.

Rare but serious complications associated with glandular fever include hepatitis, upper airway obstruction, cardiac complications, renal complications, neurological complications, haematological complications, chronic fatigue, and an increased risk of lymphoproliferative cancers and multiple sclerosis.

First and foremost, the immediate concern is providing first aid for the wound. It is important to wash the wound with soap (or chlorhexidine) and water, while gently encouraging bleeding. It is crucial not to scrub or suck the wound. Additionally, if there are any splashes or body fluid that come into contact with the eyes or mouth, they should be thoroughly washed.

For all healthcare workers who experience a needlestick injury, it is necessary to have a baseline serum sample taken and stored. This should be arranged through occupational health. The subsequent management of the injury depends on the risk of blood-borne virus transmission. This risk is determined by factors such as the source patient’s history (e.g. IV drug use), the circumstances of the injury (e.g. visible blood on the device, use of personal protection equipment), and the healthcare worker’s own characteristics (e.g. response to hepatitis B vaccination).

If the patient consents after appropriate counseling, blood may be taken from the source patient for blood-borne virus testing. However, it is important to note that the injured healthcare worker should not be responsible for counseling and obtaining consent from the patient. Lastly, all needlestick injuries should be reported to the Health Protection Agency.

In infants who are less than 4 weeks old, it is recommended to measure their body temperature using an electronic thermometer placed in the armpit.

For children between the ages of 4 weeks and 5 years, there are several methods that can be used to measure body temperature. These include using an electronic thermometer in the armpit, a chemical dot thermometer in the armpit, or an infra-red tympanic thermometer.

It is important to note that measuring temperature orally or rectally should be avoided in this age group. Additionally, forehead chemical thermometers are not reliable and should not be used.

The estimated median incubation period from HIV infection to the onset of advanced HIV disease, also known as AIDS, is around ten years.

Registered medical practitioners in England and Wales are legally obligated to inform a designated official from the Local Authority if they suspect a patient has contracted specific infectious diseases. For more information on which diseases and their causative organisms require reporting, please refer to the following resource: Notifiable diseases and causative organisms: how to report.

In cases of human bite wounds where the skin is broken but no blood is drawn, it is recommended to consider antibiotic prophylaxis, especially if the bite occurs in a high-risk area like the hands. According to NICE guidelines, a 3-day course of antibiotics is usually sufficient for prophylaxis in bite wounds. However, if the bite wound becomes infected, a 5-day course of antibiotics is advised for treatment.

Further Reading:

Bite wounds from animals and humans can cause significant injury and infection. It is important to properly assess and manage these wounds to prevent complications. In human bites, both the biter and the injured person are at risk of infection transmission, although the risk is generally low.

Bite wounds can take various forms, including lacerations, abrasions, puncture wounds, avulsions, and crush or degloving injuries. The most common mammalian bites are associated with dogs, cats, and humans.

When assessing a human bite, it is important to gather information about how and when the bite occurred, who was involved, whether the skin was broken or blood was involved, and the nature of the bite. The examination should include vital sign monitoring if the bite is particularly traumatic or sepsis is suspected. The location, size, and depth of the wound should be documented, along with any functional loss or signs of infection. It is also important to check for the presence of foreign bodies in the wound.

Factors that increase the risk of infection in bite wounds include the nature of the bite, high-risk sites of injury (such as the hands, feet, face, genitals, or areas of poor perfusion), wounds penetrating bone or joints, delayed presentation, immunocompromised patients, and extremes of age.

The management of bite wounds involves wound care, assessment and administration of prophylactic antibiotics if indicated, assessment and administration of tetanus prophylaxis if indicated, and assessment and administration of antiviral prophylaxis if indicated. For initial wound management, any foreign bodies should be removed, the wound should be encouraged to bleed if fresh, and thorough irrigation with warm, running water or normal saline should be performed. Debridement of necrotic tissue may be necessary. Bite wounds are usually not appropriate for primary closure.

Prophylactic antibiotics should be considered for human bites that have broken the skin and drawn blood, especially if they involve high-risk areas or the patient is immunocompromised. Co-amoxiclav is the first-line choice for prophylaxis, but alternative antibiotics may be used in penicillin-allergic patients. Antibiotics for wound infection should be based on wound swab culture and sensitivities.

Tetanus prophylaxis should be administered based on the cleanliness and risk level of the wound, as well as the patient’s vaccination status. Blood-borne virus risk should also be assessed, and testing for hepatitis B, hepatitis C, and HIV should be done.

The sepsis 6 pathway is a time-sensitive protocol that should be started promptly and all 6 initial steps should be completed within 1 hour. It is important not to confuse the sepsis 6 pathway with the 6 hour care bundle. Time is of the essence when managing septic patients, and initiating the sepsis 6 pathway immediately has been proven to enhance survival rates in sepsis patients.

Further Reading:

There are multiple definitions of sepsis, leading to confusion among healthcare professionals. The Sepsis 3 definition describes sepsis as life-threatening organ dysfunction caused by a dysregulated host response to infection. The Sepsis 2 definition includes infection plus two or more SIRS criteria. The NICE definition states that sepsis is a clinical syndrome triggered by the presence of infection in the blood, activating the body’s immune and coagulation systems. The Sepsis Trust defines sepsis as a dysregulated host response to infection mediated by the immune system, resulting in organ dysfunction, shock, and potentially death.

The confusion surrounding sepsis terminology is further compounded by the different versions of sepsis definitions, known as Sepsis 1, Sepsis 2, and Sepsis 3. The UK organizations RCEM and NICE have not fully adopted the changes introduced in Sepsis 3, causing additional confusion. While Sepsis 3 introduces the use of SOFA scores and abandons SIRS criteria, NICE and the Sepsis Trust have rejected the use of SOFA scores and continue to rely on SIRS criteria. This discrepancy creates challenges for emergency department doctors in both exams and daily clinical practice.

To provide some clarity, RCEM now recommends referring to national standards organizations such as NICE, SIGN, BTS, or others relevant to the area. The Sepsis Trust, in collaboration with RCEM and NICE, has published a toolkit that serves as a definitive reference point for sepsis management based on the sepsis 3 update.

There is a consensus internationally that the terms SIRS and severe sepsis are outdated and should be abandoned. Instead, the terms sepsis and septic shock should be used. NICE defines septic shock as a life-threatening condition characterized by low blood pressure despite adequate fluid replacement and organ dysfunction or failure. Sepsis 3 defines septic shock as persisting hypotension requiring vasopressors to maintain a mean arterial pressure of 65 mmHg or more, along with a serum lactate level greater than 2 mmol/l despite adequate volume resuscitation.

NICE encourages clinicians to adopt an approach of considering sepsis in all patients, rather than relying solely on strict definitions. Early warning or flag systems can help identify patients with possible sepsis.

Chagas disease, also known as American Trypanosomiasis, is a tropical illness caused by the protozoan Trypanosoma cruzi. It is transmitted by Triatomine insects, commonly known as kissing bugs, which belong to the Reduviidae family. This zoonotic disease is prevalent in Central and South America, with an estimated 8 million people infected in the region. In Brazil alone, there are approximately 120,000 new cases reported each year.

The disease progresses through two stages: the acute stage and the chronic stage. During the acute stage, many patients may not experience any symptoms, and the infection can go unnoticed. However, some individuals may exhibit symptoms such as fever, malaise, muscle pain, loss of appetite, and occasionally vomiting and diarrhea. Clinical signs may include swollen lymph nodes and enlargement of the liver and spleen. At the site of the insect bite, an inflammatory response called a chagoma can occur. This is characterized by a swollen, violet-colored nodule that can last up to 8 weeks. Another distinctive sign of acute Chagas disease is Romaña’s sign, which is eyelid swelling caused by accidentally rubbing bug feces into the eyes.

Following the acute stage, an estimated 10-30% of individuals progress to the chronic stage of Chagas disease. There is typically a latent phase between the acute and chronic phases, which can last for as long as 20-30 years. The chronic phase is associated with various complications, including cardiovascular problems such as dilated cardiomyopathy, heart failure, and arrhythmias. Gastrointestinal issues like megacolon, megaesophagus, and secondary achalasia can also arise. Neurological complications, such as neuritis, sensory and motor deficits, and encephalopathy, may occur. Additionally, psychiatric symptoms, including dementia, can manifest in some cases.

Glandular fever is typically treated with conservative management. It is a self-limiting illness that usually resolves within 2-4 weeks and can be effectively managed with over-the-counter pain relievers. Patients should also be informed about the expected duration of the illness, ways to minimize transmission, precautions to prevent complications like splenic rupture, and provided with appropriate support and guidance. These measures are outlined in the following notes.

Further Reading:

Glandular fever, also known as infectious mononucleosis or mono, is a clinical syndrome characterized by symptoms such as sore throat, fever, and swollen lymph nodes. It is primarily caused by the Epstein-Barr virus (EBV), with other viruses and infections accounting for the remaining cases. Glandular fever is transmitted through infected saliva and primarily affects adolescents and young adults. The incubation period is 4-8 weeks.

The majority of EBV infections are asymptomatic, with over 95% of adults worldwide having evidence of prior infection. Clinical features of glandular fever include fever, sore throat, exudative tonsillitis, lymphadenopathy, and prodromal symptoms such as fatigue and headache. Splenomegaly (enlarged spleen) and hepatomegaly (enlarged liver) may also be present, and a non-pruritic macular rash can sometimes occur.

Glandular fever can lead to complications such as splenic rupture, which increases the risk of rupture in the spleen. Approximately 50% of splenic ruptures associated with glandular fever are spontaneous, while the other 50% follow trauma. Diagnosis of glandular fever involves various investigations, including viral serology for EBV, monospot test, and liver function tests. Additional serology tests may be conducted if EBV testing is negative.

Management of glandular fever involves supportive care and symptomatic relief with simple analgesia. Antiviral medication has not been shown to be beneficial. It is important to identify patients at risk of serious complications, such as airway obstruction, splenic rupture, and dehydration, and provide appropriate management. Patients can be advised to return to normal activities as soon as possible, avoiding heavy lifting and contact sports for the first month to reduce the risk of splenic rupture.

Rare but serious complications associated with glandular fever include hepatitis, upper airway obstruction, cardiac complications, renal complications, neurological complications, haematological complications, chronic fatigue, and an increased risk of lymphoproliferative cancers and multiple sclerosis.

The co-epidemic of tuberculosis and HIV is a significant global health challenge at present. According to the WHO, there were 10 million new cases of tuberculosis in 2019, with approximately 11% of these cases being co-infected with HIV. Tuberculosis is the most common contagious infection in individuals with compromised immune systems due to HIV, often leading to death.

Tuberculosis is caused by an infection with the bacterium Mycobacterium tuberculosis. While it primarily affects the lungs, it can also impact various other parts of the body. The disease is spread through aerosol transmission, meaning it is transmitted through droplets in the air.

The primary symptoms of tuberculosis infection include a chronic cough, coughing up blood (haemoptysis), fever, night sweats, and weight loss. In individuals who have not been previously affected, tuberculosis can cause a primary lesion known as the Ghon focus. This lesion typically develops in the upper lobes of the lungs.

In 15-20% of cases, the infection spreads to extrapulmonary sites such as the pleura, central nervous system, lymphatics, bones, joints, and genitourinary system. Extrapulmonary tuberculosis that affects the spine is known as Pott’s disease, primarily affecting the lower thoracic and upper lumbar vertebrae. Cervical tuberculous lymphadenopathy, also known as scrofula, is characterized by cold abscesses without erythema or warmth.

Only a small percentage of patients, around 5-10%, go on to develop post-primary tuberculosis, also known as reactivation tuberculosis. This typically occurs a year or two after the primary infection and is more likely to happen in individuals with a weakened immune system. Reactivation tuberculosis often involves the lung apex.

Two types of tapeworms, Taenia solium and Taenia saginata, can infest humans. Infestation occurs when people consume meat from intermediate hosts that contain the parasite’s tissue stages. Tapeworms compete for nutrients and infestation is often without symptoms. However, in more severe cases, individuals may experience epigastric pain, diarrhea, and vomiting. Diagnosis involves identifying characteristic eggs in the patient’s stool.

Taenia solium infestation can also lead to a condition called cysticercosis. This occurs when larval cysts infiltrate and spread throughout the lung, liver, eye, or brain. Cysticercosis presents with neurological symptoms, seizures, and impaired vision. Confirmation of cysticercosis involves the presence of antibodies and imaging tests such as chest X-rays and CT brain scans.

The treatment for tapeworm infestation is highly effective and involves the use of medications like niclosamide or praziquantel. However, it is important to seek specialist advice when managing Taenia infections in the central nervous system, as severe inflammatory reactions can occur.

The presence of serum HBsAg for more than 6 months indicates chronic HBV infection. HBeAg can be detected in the serum during the early stages of acute infection and some chronic infections. Higher levels of virus replication are usually associated with the presence of HBeAg, making individuals with chronic HBV more infectious. If HBeAg is cleared, anti-HBe is typically detected, indicating lower infectivity. The presence of anti-HBe, along with a decline in HBV-DNA, suggests control of viral replication and the likelihood of resolving acute hepatitis B. The presence of anti-HBc indicates current or past HBV infection, appearing at the onset of symptoms in acute infection and persisting for life. However, it may be absent in the early stages of acute infection. Anti-HBc IgM indicates recent HBV infection within the last six months and can help differentiate between acute and chronic infection. Over time, it is gradually replaced by IgG anti-HBc. IgG anti-HBc generally persists for life and indicates past infection. Anti-HBs indicates recovery from and immunity to HBV. If anti-HBs is present without anti-HBc, it suggests immunization. The quantification of anti-HBs is used to measure the response to vaccination.

Further Reading:

Hepatitis B is a viral infection that is transmitted through exposure to infected blood or body fluids. It can also be passed from mother to child during childbirth. The incubation period for hepatitis B is typically 6-20 weeks. Common symptoms of hepatitis B include fever, jaundice, and elevated liver transaminases.

Complications of hepatitis B infection can include chronic hepatitis, which occurs in 5-10% of cases, fulminant liver failure, hepatocellular carcinoma, glomerulonephritis, polyarteritis nodosa, and cryoglobulinemia.

Immunization against hepatitis B is recommended for various at-risk groups, including healthcare workers, intravenous drug users, sex workers, close family contacts of infected individuals, and those with chronic liver disease or kidney disease. The vaccine contains HBsAg adsorbed onto an aluminum hydroxide adjuvant and is prepared using recombinant DNA technology. Most vaccination schedules involve three doses of the vaccine, with a booster recommended after 5 years.

Around 10-15% of adults may not respond adequately to the vaccine. Risk factors for poor response include age over 40, obesity, smoking, alcohol excess, and immunosuppression. Testing for anti-HBs levels is recommended for healthcare workers and patients with chronic kidney disease. Interpretation of anti-HBs levels can help determine the need for further vaccination or testing for infection.

In terms of serology, the presence of HBsAg indicates acute disease if present for 1-6 months, and chronic disease if present for more than 6 months. Anti-HBs indicates immunity, either through exposure or immunization. Anti-HBc indicates previous or current infection, with IgM anti-HBc appearing during acute or recent infection and IgG anti-HBc persisting. HbeAg is a marker of infectivity.

Management of hepatitis B involves notifying the Health Protection Unit for surveillance and contact tracing. Patients should be advised to avoid alcohol and take precautions to minimize transmission to partners and contacts. Referral to a gastroenterologist or hepatologist is recommended for all patients. Symptoms such as pain, nausea, and itch can be managed with appropriate drug treatment. Pegylated interferon-alpha and other antiviral medications like tenofovir and entecavir may be used to suppress viral replication in chronic carriers.

The estimated rates of seroconversion are provided below:

– Percutaneous exposure of a non-immune individual to an HBeAg positive contact results in a seroconversion rate of approximately 30%.

– When exposed to HCV-infected blood with detectable RNA through percutaneous means, the seroconversion rate ranges from 0.5% to 1.8%.

– Mucocutaneous exposure to HIV-infected blood leads to a seroconversion rate of 0.1%.

– Lastly, percutaneous exposure to HIV-infected blood results in a seroconversion rate of 0.3%.

Please note that these rates are estimates and may vary depending on individual circumstances.

Plasmodium falciparum malaria is transmitted by female mosquitoes of the Anopheles genus. The Aedes genus, on the other hand, is responsible for spreading diseases like dengue fever and yellow fever. The parasite enters hepatocytes and undergoes asexual reproduction, resulting in the release of merozoites into the bloodstream. These merozoites then invade the red blood cells of the host. The incubation period for Plasmodium falciparum malaria ranges from 7 to 14 days.

The main symptom of malaria is known as the malarial paroxysm, which consists of a cyclical pattern of cold chills, followed by a stage of intense heat, and finally a period of profuse sweating as the fever subsides. However, some individuals may experience a continuous fever instead.

Currently, the recommended treatment for P. falciparum malaria is artemisinin-based combination therapy (ACT). This involves combining fast-acting artemisinin-based compounds with drugs from a different class. Companion drugs used in ACT include lumefantrine, mefloquine, amodiaquine, sulfadoxine/pyrimethamine, piperaquine, and chlorproguanil/dapsone. Artemisinin derivatives such as dihydroartemisinin, artesunate, and artemether are also used.

If artemisinin combination therapy is not available, oral quinine or atovaquone with proguanil hydrochloride can be used as an alternative. However, quinine is not well-tolerated for prolonged treatment and should be combined with another drug, typically oral doxycycline (or clindamycin for pregnant women and young children).

Severe or complicated cases of falciparum malaria require specialized care in a high dependency unit or intensive care setting. Intravenous artesunate is recommended for all patients with severe or complicated falciparum malaria, as well as those at high risk of developing severe disease (e.g., if more than 2% of red blood cells are parasitized) or if the patient is unable to take oral treatment. After a minimum of 24 hours of intravenous artesunate treatment and improvement in the patient’s condition, a full course of artemisinin combination therapy should be administered orally.

Patients who have been diagnosed with Scarlet fever should be instructed to stay away from school or work until at least 24 hours after they have started taking antibiotics. It is also important for them to practice good hygiene habits.

Further Reading:

Scarlet fever is a reaction to erythrogenic toxins produced by Group A haemolytic streptococci, usually Streptococcus pyogenes. It is more common in children aged 2-6 years, with the peak incidence at 4 years. The typical presentation of scarlet fever includes fever, malaise, sore throat (tonsillitis), and a rash. The rash appears 1-2 days after the fever and sore throat symptoms and consists of fine punctate erythema that first appears on the torso and spares the face. The rash has a rough ‘sandpaper’ texture and desquamation occurs later, particularly around the fingers and toes. Another characteristic feature is the ‘strawberry tongue’, which initially has a white coating and swollen, reddened papillae, and later becomes red and inflamed. Diagnosis is usually made by a throat swab, but antibiotic treatment should be started immediately without waiting for the results. The recommended treatment is oral penicillin V, but patients with a penicillin allergy should be given azithromycin. Children can return to school 24 hours after starting antibiotics. Scarlet fever is a notifiable disease. Complications of scarlet fever include otitis media, rheumatic fever, and acute glomerulonephritis.

Malaria is a contagious illness that is spread by female mosquitoes of the Anopheles genus. It is a parasitic infection caused by the Plasmodium genus. There are five species of Plasmodium that are known to cause disease in humans: Plasmodium falciparum, Plasmodium ovale, Plasmodium vivax, Plasmodium malariae, and Plasmodium knowlesi.

The main symptom of malaria is the malarial paroxysm, which is a recurring pattern of symptoms. It begins with a cold phase, during which the patient experiences intense chills. This is followed by a hot stage, where the patient feels extremely hot. Finally, there is a sweating stage, during which the fever subsides and the patient sweats profusely. Upon examination, the patient may exhibit signs of anemia, jaundice, and have an enlarged liver and spleen, but there is no evidence of swollen lymph nodes.

If a patient develops haemoglobinuria (the presence of hemoglobin in the urine) and renal failure after treatment, it may indicate a condition called blackwater fever, which is caused by Plasmodium falciparum. In this condition, an autoimmune reaction occurs between the parasite and quinine, leading to the destruction of red blood cells, hemoglobinuria, jaundice, and renal failure. Blackwater fever can be life-threatening.

It is recommended to administer prophylactic oral antibiotics to individuals who have experienced a cat bite that has broken the skin and cause bleeding. For patients over one month of age, co-amoxiclav should be prescribed for a duration of 3 days. In cases where the patient is allergic to penicillin, a combination of metronidazole and doxycycline should be given for 3 days. If the wound shows signs of infection, the antibiotic treatment should be extended to 5 days.

Prophylactic oral antibiotics may also be considered for individuals with a cat bite that has broken the skin but has not caused bleeding, especially if the wound is deep.

Debridement, the removal of dead tissue, should be considered for wounds that are damaged, have abscess formation, lymphangitis, severe cellulitis, osteomyelitis, septic arthritis, necrotising fasciitis, or infected bite wounds that are not responding to treatment. Additionally, individuals who are systemically unwell should also undergo debridement.

Antibiotics should also be considered for other animal bites, such as dog bites, that have broken the skin and cause bleeding.

Further Reading:

Bite wounds from animals and humans can cause significant injury and infection. It is important to properly assess and manage these wounds to prevent complications. In human bites, both the biter and the injured person are at risk of infection transmission, although the risk is generally low.

Bite wounds can take various forms, including lacerations, abrasions, puncture wounds, avulsions, and crush or degloving injuries. The most common mammalian bites are associated with dogs, cats, and humans.

When assessing a human bite, it is important to gather information about how and when the bite occurred, who was involved, whether the skin was broken or blood was involved, and the nature of the bite. The examination should include vital sign monitoring if the bite is particularly traumatic or sepsis is suspected. The location, size, and depth of the wound should be documented, along with any functional loss or signs of infection. It is also important to check for the presence of foreign bodies in the wound.

Factors that increase the risk of infection in bite wounds include the nature of the bite, high-risk sites of injury (such as the hands, feet, face, genitals, or areas of poor perfusion), wounds penetrating bone or joints, delayed presentation, immunocompromised patients, and extremes of age.

The management of bite wounds involves wound care, assessment and administration of prophylactic antibiotics if indicated, assessment and administration of tetanus prophylaxis if indicated, and assessment and administration of antiviral prophylaxis if indicated. For initial wound management, any foreign bodies should be removed, the wound should be encouraged to bleed if fresh, and thorough irrigation with warm, running water or normal saline should be performed. Debridement of necrotic tissue may be necessary. Bite wounds are usually not appropriate for primary closure.

Prophylactic antibiotics should be considered for human bites that have broken the skin and drawn blood, especially if they involve high-risk areas or the patient is immunocompromised. Co-amoxiclav is the first-line choice for prophylaxis, but alternative antibiotics may be used in penicillin-allergic patients. Antibiotics for wound infection should be based on wound swab culture and sensitivities.

Tetanus prophylaxis should be administered based on the cleanliness and risk level of the wound, as well as the patient’s vaccination status. Blood-borne virus risk should also be assessed, and testing for hepatitis B, hepatitis C, and HIV should be done.

For patients with sepsis and hypotension, it is recommended to administer 30ml of crystalloid fluid per kilogram of body weight. However, if the patient does not have acute kidney injury, is not hypotensive, and has a lactate level below 2 mmol/l, a 500ml immediate dose may be given.

Further Reading:

There are multiple definitions of sepsis, leading to confusion among healthcare professionals. The Sepsis 3 definition describes sepsis as life-threatening organ dysfunction caused by a dysregulated host response to infection. The Sepsis 2 definition includes infection plus two or more SIRS criteria. The NICE definition states that sepsis is a clinical syndrome triggered by the presence of infection in the blood, activating the body’s immune and coagulation systems. The Sepsis Trust defines sepsis as a dysregulated host response to infection mediated by the immune system, resulting in organ dysfunction, shock, and potentially death.

The confusion surrounding sepsis terminology is further compounded by the different versions of sepsis definitions, known as Sepsis 1, Sepsis 2, and Sepsis 3. The UK organizations RCEM and NICE have not fully adopted the changes introduced in Sepsis 3, causing additional confusion. While Sepsis 3 introduces the use of SOFA scores and abandons SIRS criteria, NICE and the Sepsis Trust have rejected the use of SOFA scores and continue to rely on SIRS criteria. This discrepancy creates challenges for emergency department doctors in both exams and daily clinical practice.

To provide some clarity, RCEM now recommends referring to national standards organizations such as NICE, SIGN, BTS, or others relevant to the area. The Sepsis Trust, in collaboration with RCEM and NICE, has published a toolkit that serves as a definitive reference point for sepsis management based on the sepsis 3 update.

There is a consensus internationally that the terms SIRS and severe sepsis are outdated and should be abandoned. Instead, the terms sepsis and septic shock should be used. NICE defines septic shock as a life-threatening condition characterized by low blood pressure despite adequate fluid replacement and organ dysfunction or failure. Sepsis 3 defines septic shock as persisting hypotension requiring vasopressors to maintain a mean arterial pressure of 65 mmHg or more, along with a serum lactate level greater than 2 mmol/l despite adequate volume resuscitation.

NICE encourages clinicians to adopt an approach of considering sepsis in all patients, rather than relying solely on strict definitions. Early warning or flag systems can help identify patients with possible sepsis.

The tricuspid valve is the most commonly affected valve in cases of infective endocarditis among intravenous drug users. This means that when IV drug users develop infective endocarditis, it is most likely to affect the tricuspid valve. On the other hand, in cases of native valve endocarditis and prosthetic valve endocarditis, the mitral valve is the valve that is most commonly affected.

Further Reading:

Infective endocarditis (IE) is an infection that affects the innermost layer of the heart, known as the endocardium. It is most commonly caused by bacteria, although it can also be caused by fungi or viruses. IE can be classified as acute, subacute, or chronic depending on the duration of illness. Risk factors for IE include IV drug use, valvular heart disease, prosthetic valves, structural congenital heart disease, previous episodes of IE, hypertrophic cardiomyopathy, immune suppression, chronic inflammatory conditions, and poor dental hygiene.

The epidemiology of IE has changed in recent years, with Staphylococcus aureus now being the most common causative organism in most industrialized countries. Other common organisms include coagulase-negative staphylococci, streptococci, and enterococci. The distribution of causative organisms varies depending on whether the patient has a native valve, prosthetic valve, or is an IV drug user.

Clinical features of IE include fever, heart murmurs (most commonly aortic regurgitation), non-specific constitutional symptoms, petechiae, splinter hemorrhages, Osler’s nodes, Janeway’s lesions, Roth’s spots, arthritis, splenomegaly, meningism/meningitis, stroke symptoms, and pleuritic pain.

The diagnosis of IE is based on the modified Duke criteria, which require the presence of certain major and minor criteria. Major criteria include positive blood cultures with typical microorganisms and positive echocardiogram findings. Minor criteria include fever, vascular phenomena, immunological phenomena, and microbiological phenomena. Blood culture and echocardiography are key tests for diagnosing IE.

In summary, infective endocarditis is an infection of the innermost layer of the heart that is most commonly caused by bacteria. It can be classified as acute, subacute, or chronic and can be caused by a variety of risk factors. Staphylococcus aureus is now the most common causative organism in most industrialized countries. Clinical features include fever, heart murmurs, and various other symptoms. The diagnosis is based on the modified Duke criteria, which require the presence of certain major and minor criteria. Blood culture and echocardiography are important tests for diagnosing IE.

In a child with a non-blanching rash, it is important to always consider the possibility of meningococcal septicaemia. This is especially true if the child appears unwell, has purpura (lesions larger than 2 mm in diameter), a capillary refill time of more than 3 seconds, or neck stiffness. In the UK, most cases of meningococcal septicaemia are caused by Neisseria meningitidis group B, although the vaccination program for Neisseria meningitidis group C has reduced the prevalence of this type. A vaccine for group B disease has now been introduced for children. It is also worth noting that Streptococcus pneumoniae can also cause meningitis.

In this particular case, the child is clearly very sick and showing signs of septic shock. It is crucial to administer a single dose of benzylpenicillin without delay and arrange for immediate transfer to the nearest Emergency Department via ambulance.

The recommended doses of benzylpenicillin based on age are as follows:
– Infants under 1 year of age: 300 mg of IM or IV benzylpenicillin
– Children aged 1 to 9 years: 600 mg of IM or IV benzylpenicillin
– Children and adults aged 10 years or older: 1.2 g of IM or IV benzylpenicillin.

The traffic light system is a useful tool for evaluating the potential risk of serious illness in children. This system categorizes clinical features into three groups based on severity: red (high-risk), amber (intermediate-risk), and green (low-risk).

Children displaying any of the following symptoms or signs fall into the high-risk group for serious illness: pale/mottled/ashen/blue skin, lips or tongue; lack of response to social cues; appearing unwell to a healthcare professional; inability to wake or stay awake when roused; weak, high-pitched, or continuous cry; grunting; respiratory rate exceeding 60 breaths per minute; moderate or severe chest indrawing; reduced skin turgor; and bulging fontanelle.

Children exhibiting any of the following symptoms or signs are considered at least intermediate-risk for serious illness: pallor of skin, lips or tongue reported by parent or caregiver; abnormal response to social cues; absence of a smile; waking only with prolonged stimulation; decreased activity; nasal flaring; dry mucous membranes; poor feeding in infants; reduced urine output; and rigors.

Children displaying any of the following symptoms or signs are classified as low-risk for serious illness: normal color of skin, lips, and tongue; normal response to social cues; contentment and smiles; staying awake or quickly awakening; strong normal cry or absence of crying; normal skin and eyes; and moist mucous membranes.

To summarize, children with fever and any symptoms or signs in the red column are considered high-risk, while those with fever and any symptoms or signs in the amber column (but none in the red column) are considered intermediate-risk. Children with symptoms and signs in the green column (and none in the amber or red columns) are classified as low-risk.

For more information, you can refer to the NICE guidelines on the assessment and initial management of fever in children under 5, as well as the NICE Clinical Knowledge Summary on the management of feverish children.

Two types of tapeworms, Taenia solium and Taenia saginata, can infest humans. Infestation occurs when people consume meat from intermediate hosts that contain the parasite’s tissue stages. Tapeworms compete for nutrients and infestation is often without symptoms. However, in more severe cases, individuals may experience epigastric pain, diarrhea, and vomiting. Diagnosis involves identifying characteristic eggs in the patient’s stool.

Taenia solium infestation can also lead to a condition called cysticercosis. This occurs when larval cysts infiltrate and spread throughout the lung, liver, eye, or brain. Cysticercosis presents with neurological symptoms, seizures, and impaired vision. Confirmation of cysticercosis involves the presence of antibodies and imaging tests such as chest X-rays and CT brain scans.

The treatment for tapeworm infestation is highly effective and involves the use of medications like niclosamide or praziquantel. However, it is important to seek specialist advice when managing Taenia infections in the central nervous system, as severe inflammatory reactions can occur.

Public Health England (PHE) has a primary goal of promptly identifying potential disease outbreaks and epidemics. While accuracy of diagnosis is important, it is not the main focus. Since 1968, clinical suspicion of a notifiable infection has been sufficient for reporting.
Registered medical practitioners (RMPs) are legally obligated to notify the designated proper officer at their local council or local health protection team (HPT) if they suspect cases of certain infectious diseases.
The Health Protection (Notification) Regulations 2010 specify the diseases that RMPs must report to the proper officers at local authorities. These diseases include acute encephalitis, acute infectious hepatitis, acute meningitis, acute poliomyelitis, anthrax, botulism, brucellosis, cholera, COVID-19, diphtheria, enteric fever (typhoid or paratyphoid fever), food poisoning, haemolytic uraemic syndrome (HUS), infectious bloody diarrhoea, invasive group A streptococcal disease, Legionnaires’ disease, leprosy, malaria, measles, meningococcal septicaemia, mumps, plague, rabies, rubella, severe acute respiratory syndrome (SARS), scarlet fever, smallpox, tetanus, tuberculosis, typhus, viral haemorrhagic fever (VHF), whooping cough, and yellow fever. However, as of April 2010, ophthalmia neonatorum is no longer considered a notifiable disease in the UK.

Respiratory alkalosis can be caused by hyperventilation, such as during periods of anxiety. It can also be a result of conditions like pulmonary embolism, CNS disorders (such as stroke or encephalitis), altitude, pregnancy, or the early stages of aspirin overdose.

Respiratory acidosis is often associated with chronic obstructive pulmonary disease (COPD) or life-threatening asthma. Other causes include pulmonary edema, sedative drug overdose (such as opiates or benzodiazepines), neuromuscular disease, obesity, or certain medications.

Metabolic alkalosis can occur due to vomiting, potassium depletion (often caused by diuretic usage), Cushing’s syndrome, or Conn’s syndrome.

Metabolic acidosis with a raised anion gap can be caused by conditions like lactic acidosis (which can result from hypoxemia, shock, sepsis, or infarction) or ketoacidosis (commonly seen in diabetes, starvation, or alcohol excess). Other causes include renal failure or poisoning (such as late stages of aspirin overdose, methanol, or ethylene glycol).

Metabolic acidosis with a normal anion gap can be attributed to conditions like renal tubular acidosis, diarrhea, ammonium chloride ingestion, or adrenal insufficiency.

Glandular fever, also known as infectious mononucleosis or mono, is a clinical syndrome characterized by symptoms such as sore throat, fever, and swollen lymph nodes. It is primarily caused by the Epstein-Barr virus (EBV), with other viruses and infections accounting for the remaining cases. Glandular fever is transmitted through infected saliva and primarily affects adolescents and young adults. The incubation period is 4-8 weeks.

The majority of EBV infections are asymptomatic, with over 95% of adults worldwide having evidence of prior infection. Clinical features of glandular fever include fever, sore throat, exudative tonsillitis, lymphadenopathy, and prodromal symptoms such as fatigue and headache. Splenomegaly (enlarged spleen) and hepatomegaly (enlarged liver) may also be present, and a non-pruritic macular rash can sometimes occur.

Glandular fever can lead to complications such as splenic rupture, which increases the risk of rupture in the spleen. Approximately 50% of splenic ruptures associated with glandular fever are spontaneous, while the other 50% follow trauma. Diagnosis of glandular fever involves various investigations, including viral serology for EBV, monospot test, and liver function tests. Additional serology tests may be conducted if EBV testing is negative.

Management of glandular fever involves supportive care and symptomatic relief with simple analgesia. Antiviral medication has not been shown to be beneficial. It is important to identify patients at risk of serious complications, such as airway obstruction, splenic rupture, and dehydration, and provide appropriate management. Patients can be advised to return to normal activities as soon as possible, avoiding heavy lifting and contact sports for the first month to reduce the risk of splenic rupture.

Rare but serious complications associated with glandular fever include hepatitis, upper airway obstruction, cardiac complications, renal complications, neurological complications, haematological complications, chronic fatigue, and an increased risk of lymphoproliferative cancers and multiple sclerosis.

This is a complex situation that presents both ethical and medico-legal challenges. While patients have a right to confidentiality, it is important to recognize that this right is not absolute and may not apply in every circumstance. There are certain situations where it is appropriate to breach confidentiality, such as when mandated by law or when there is a threat to public health. However, it is crucial to make every effort to persuade the patient against disclosure and to inform them of your intentions.

In this particular case, the patient has disclosed to you that they have recently been diagnosed with HIV, which they believe was contracted from a sexual encounter outside of their marriage. They have explicitly stated that they do not want you to inform their wife, who is in the early stages of pregnancy. Before taking any action, it is advisable to gather all the relevant facts and confirm the patient’s HIV diagnosis through their health records, including any other blood-borne viruses.

If the facts are indeed confirmed, it is important to continue efforts to persuade the patient of the necessity for their wife to be informed. If she has been exposed, she could greatly benefit from testing and starting antiretroviral therapy. Additionally, specialized care during early pregnancy could help prevent transmission of the virus to the unborn child. However, if the patient continues to refuse disclosure, you have the right to breach confidentiality, but it is crucial to inform the patient of your intentions beforehand. Seeking support from your defense organization is also recommended in such situations.

For further information, you may refer to the GMC Guidance on Confidentiality, specifically the section on disclosing information about serious communicable diseases.