Infection Flashcards
Q: What is the most common cause of acute pyelonephritis?
A: Ascending infection, typically E. coli from the lower urinary tract.
Q: How can acute pyelonephritis also occur aside from ascending infection?
A: Through bloodstream spread of infection, such as in sepsis.
Q: What are the clinical features of acute pyelonephritis?
A: Fever, rigors, loin pain, nausea/vomiting, and symptoms of cystitis (dysuria, urinary frequency).
Q: What symptoms of cystitis may be present in acute pyelonephritis?
A: Dysuria and urinary frequency.
Q: What investigation should be done before starting antibiotics in acute pyelonephritis?
A: A mid-stream urine (MSU) sample should be sent.
Q: When should hospital admission be considered for acute pyelonephritis?
A: For patients with signs of acute pyelonephritis.
Q: What is the recommended antibiotic treatment for acute pyelonephritis according to the BNF?
A: A broad-spectrum cephalosporin or a quinolone (for non-pregnant women) for 7-10 days.
Q: What causes amoebiasis?
A: Entamoeba histolytica (an amoeboid protozoan).
Q: How is amoebiasis spread?
A: By the faecal-oral route.
Q: What are the possible clinical presentations of amoebiasis?
A: Asymptomatic infection, mild diarrhoea, or severe amoebic dysentery.
Q: What serious conditions can amoebiasis cause?
A: Liver and colonic abscesses.
Q: What are the symptoms of amoebic dysentery?
A: Profuse, bloody diarrhoea.
Q: What can be seen in stool microscopy for amoebic dysentery if examined within 15 minutes or kept warm?
A: Trophozoites (known as a ‘hot stool’).
Q: What is the treatment for amoebic dysentery?
A: Oral metronidazole and a ‘luminal agent’ (e.g., diloxanide furoate).
Q: Where is an amoebic liver abscess usually located?
A: Usually a single mass in the right lobe, but it may be multiple.
Q: How are the contents of an amoebic liver abscess often described?
A: As ‘anchovy sauce’.
Q: What are the features of an amoebic liver abscess?
A: Fever, right upper quadrant pain, systemic symptoms (e.g., malaise), and hepatomegaly.
Q: What investigations are used for an amoebic liver abscess?
A: Ultrasound and serology (positive in > 95%).
Q: What is the management for an amoebic liver abscess?
A: Oral metronidazole and a ‘luminal agent’ (e.g., diloxanide furoate).
Q: What is the most common organism isolated from animal bites, especially from dogs and cats?
A: Pasteurella multocida.
Q: How should an animal bite wound be managed?
A: Cleanse the wound, and puncture wounds should not be sutured unless cosmesis is at risk.
Q: What is the current BNF recommendation for treating animal bites?
A: Co-amoxiclav.
Q: What should be prescribed if the patient is allergic to penicillin for an animal bite?
A: Doxycycline + metronidazole.
Q: What type of infection do human bites commonly cause?
A: Multimicrobial infection, including both aerobic and anaerobic bacteria.
Q: What is the recommended treatment for human bites?
A: Co-amoxiclav, as for animal bites.
Q: What viral infections should be considered in human bites?
A: HIV and hepatitis C.
Q: What causes anthrax?
A: Bacillus anthracis, a Gram-positive rod.
Q: How is anthrax spread?
A: By infected carcasses.
Q: What are the features of cutaneous anthrax?
A: Causes painless black eschar (cutaneous ‘malignant pustule’), typically painless and non-tender, may cause marked oedema.
Q: Can anthrax cause gastrointestinal symptoms?
A: Yes, anthrax can cause gastrointestinal bleeding.
Q: What is the current Health Protection Agency advice for the initial management of cutaneous anthrax?
A: Ciprofloxacin.
Q: What is the recommended treatment for exacerbations of chronic bronchitis?
A: Amoxicillin or tetracycline or clarithromycin.
Q: What is the recommended treatment for uncomplicated community-acquired pneumonia?
A: Amoxicillin (Doxycycline or clarithromycin in penicillin-allergic patients, add flucloxacillin if staphylococci suspected, e.g., in influenza).
Q: What is the recommended treatment for pneumonia possibly caused by atypical pathogens?
A: Clarithromycin.
Q: What is the recommended treatment for hospital-acquired pneumonia within 5 days of admission?
A: Co-amoxiclav or cefuroxime.
Q: What is the recommended treatment for hospital-acquired pneumonia more than 5 days after admission?
A: Piperacillin with tazobactam OR a broad-spectrum cephalosporin (e.g., ceftazidime) OR a quinolone (e.g., ciprofloxacin).
Q: What is the recommended treatment for lower urinary tract infection?
A: Trimethoprim or nitrofurantoin. Alternative: amoxicillin or cephalosporin.
Q: What is the recommended treatment for acute pyelonephritis?
A: Broad-spectrum cephalosporin or quinolone.
Q: What is the recommended treatment for acute prostatitis?
A: Quinolone or trimethoprim.
Q: What is the recommended treatment for impetigo?
A: Topical hydrogen peroxide, oral flucloxacillin or erythromycin if widespread.
Q: What is the recommended treatment for cellulitis?
A: Flucloxacillin (clarithromycin, erythromycin, or doxycycline if penicillin-allergic).
Q: What is the recommended treatment for cellulitis near the eyes or nose?
A: Co-amoxiclav (clarithromycin + metronidazole if penicillin-allergic).
Q: What is the recommended treatment for erysipelas?
A: Flucloxacillin (clarithromycin, erythromycin, or doxycycline if penicillin-allergic).
Q: What is the recommended treatment for animal or human bites?
A: Co-amoxiclav (doxycycline + metronidazole if penicillin-allergic).
Q: What is the recommended treatment for mastitis during breast-feeding?
A: Flucloxacillin.
Q: What is the recommended treatment for throat infections?
A: Phenoxymethylpenicillin (erythromycin alone if penicillin-allergic).
Q: What is the recommended treatment for sinusitis?
A: Phenoxymethylpenicillin.
Q: What is the recommended treatment for otitis media?
A: Amoxicillin (erythromycin if penicillin-allergic).
Q: What is the recommended treatment for otitis externa?
A: Flucloxacillin (erythromycin if penicillin-allergic).
Q: What is the recommended treatment for a periapical or periodontal abscess?
A: Amoxicillin.
Q: What is the recommended treatment for acute necrotising ulcerative gingivitis?
A: Metronidazole.
Q: What is the recommended treatment for gonorrhoea?
A: Intramuscular ceftriaxone.
Q: What is the recommended treatment for chlamydia?
A: Doxycycline or azithromycin.
Q: What is the recommended treatment for pelvic inflammatory disease?
A: Oral ofloxacin + oral metronidazole or intramuscular ceftriaxone + oral doxycycline + oral metronidazole.
Q: What is the recommended treatment for syphilis?
A: Benzathine benzylpenicillin or doxycycline or erythromycin.
Q: What is the recommended treatment for bacterial vaginosis?
A: Oral or topical metronidazole or topical clindamycin.
Q: What is the recommended treatment for the first episode of Clostridioides difficile infection?
A: Oral vancomycin.
Q: What is the recommended treatment for the second or subsequent episode of Clostridioides difficile infection?
A: Oral fidaxomicin.
Q: What is the recommended treatment for Campylobacter enteritis?
A: Clarithromycin.
Q: What is the recommended treatment for Salmonella (non-typhoid)?
A: Ciprofloxacin.
Q: What is the recommended treatment for shigellosis?
A: Ciprofloxacin.
Q: What is an aspergilloma?
A: A mycetoma (mass-like fungus ball) which often colonises an existing lung cavity (e.g. secondary to tuberculosis, lung cancer, or cystic fibrosis).
Q: What are the usual symptoms of an aspergilloma?
A: Usually asymptomatic, but may include cough and haemoptysis (which may be severe).
Q: What might be seen on a chest x-ray of a patient with an aspergilloma?
A: A rounded opacity, and a crescent sign may be present.
Q: What investigation finding is indicative of aspergilloma?
A: High titres of Aspergillus precipitins.
Q: What conditions can lead to the formation of lung cavities that aspergillomas colonise?
A: Tuberculosis, lung cancer, and cystic fibrosis.
Q: What type of bacterium is Bacillus cereus?
A: Bacillus cereus is a gram-positive rod, which is highly adaptable to extremes of pH and oxygen levels.
Q: What are the two main clinical syndromes caused by Bacillus cereus food poisoning?
A: An emetic syndrome and a diarrhoeal syndrome.
Q: What causes the emetic syndrome in Bacillus cereus food poisoning?
A: Ingestion of the heat-stable toxin cereulide.
Q: How soon do symptoms of the emetic syndrome typically occur after ingestion of Bacillus cereus toxin?
A: Symptoms typically occur between 0.5 and 6 hours of ingestion.
Q: What causes the diarrhoeal syndrome in Bacillus cereus food poisoning?
A: Separate exotoxins such as haemolysin BL.
Q: How soon do symptoms of the diarrhoeal syndrome typically occur after ingestion of Bacillus cereus?
A: Symptoms typically occur 8-16 hours after ingestion.
Q: What are the typical symptoms of the diarrhoeal syndrome caused by Bacillus cereus?
A: Crampy abdominal pain and diarrhoea.
Q: Where is Bacillus cereus commonly found in the environment?
A: In soil, fresh water, and salt water. It is also frequently considered a transient commensal organism in the human GI tract and has been found in disinfectant alcohol hand gel.
Q: In which patients is Bacillus cereus a significant cause of infection?
A: Immunosuppressed patients, intravenous drug users, and neonates.
Q: What types of infections can Bacillus cereus cause in immunosuppressed patients?
A: Bacteraemia, endocarditis, musculoskeletal, and CNS infections.
Q: What does bacterial vaginosis (BV) describe?
A: An overgrowth of predominantly anaerobic organisms such as Gardnerella vaginalis, leading to a fall in lactic acid-producing aerobic lactobacilli and a raised vaginal pH.
Q: Is bacterial vaginosis considered a sexually transmitted infection?
A: No, but it is seen almost exclusively in sexually active women.
Q: What are the features of bacterial vaginosis?
A: Vaginal discharge that is ‘fishy’ and offensive; asymptomatic in 50% of cases.
Q: What is Amsel’s criteria for the diagnosis of bacterial vaginosis?
A: Three of the following four points should be present: thin, white homogenous discharge; clue cells on microscopy (stippled vaginal epithelial cells); vaginal pH > 4.5; positive whiff test (fishy odor upon addition of potassium hydroxide).
Q: What is the recommended management for asymptomatic bacterial vaginosis?
A: Treatment is not usually required unless the woman is undergoing a termination of pregnancy.
Q: What is the recommended treatment for symptomatic bacterial vaginosis?
A: Oral metronidazole for 5-7 days; a single oral dose of metronidazole 2g may be used if adherence is an issue; topical metronidazole or topical clindamycin are alternatives.
Q: What are the risks associated with bacterial vaginosis in pregnancy?
A: Increased risk of preterm labor, low birth weight, chorioamnionitis, and late miscarriage.
Q: What is the current recommendation for treating bacterial vaginosis during pregnancy?
A: Oral metronidazole is recommended throughout pregnancy; if asymptomatic, discuss treatment with the woman’s obstetrician; if symptomatic, use oral metronidazole for 5-7 days or topical treatment. The higher, stat dose of metronidazole is not recommended.
Q: What groups require a tuberculin skin test before receiving the BCG vaccine?
A: Infants older than 6 months, tuberculin-negative contacts of TB cases, and new entrants over 6 years old from high-incidence countries.
Q: What is the vaccine made of?
A: The BCG vaccine contains live attenuated Mycobacterium bovis.
Q: How is the BCG vaccine administered?
A: It is given intradermally, usually to the lateral aspect of the left upper arm.
Q: Can the BCG vaccine be given with other vaccines?
A: Yes, it can be given simultaneously with other live vaccines, but if not, there should be a 4-week interval.
Q: What are the contraindications for the BCG vaccine?
A: Previous BCG vaccination, a past history of tuberculosis, HIV, pregnancy, and a positive tuberculin test (Heaf or Mantoux).
Q: What are the common clinical problems caused by bed bugs?
A: Itchy skin rashes, bites, and allergic symptoms.
Q: What is the cause of bed bug infestation?
A: Infestation with Cimex lectularius.
Q: Where do bed bugs typically thrive?
A: In mattresses or fabrics.
Q: How is itch from bed bug bites managed?
A: Topical hydrocortisone can be used to control itch.
Q: What is the definitive management for bed bug infestation?
A: A pest management company and fumigation of the house.
Q: How can bed bug numbers be controlled?
A: By hot-washing bed linen and using mattress covers.
Q: What type of bacterium causes botulism?
A: Clostridium botulinum, a gram-positive anaerobic bacillus.
Q: What does the botulinum toxin do?
A: It irreversibly blocks the release of acetylcholine, leading to paralysis.
Q: How can botulism occur?
A: It can result from eating contaminated food (e.g., tinned food) or intravenous drug use.
Q: What are the common features of botulism?
A: The patient is usually fully conscious with no sensory disturbance, and may experience flaccid paralysis, diplopia, ataxia, and bulbar palsy.
Q: What is the treatment for botulism?
A: Botulism antitoxin and supportive care.
Q: What is the most common bacterial cause of infectious intestinal disease in the UK?
A: Campylobacter jejuni.
Q: How is Campylobacter infection spread?
A: It is spread by the faecal-oral route.
Q: What are the common features of Campylobacter infection?
A: Prodrome with headache and malaise, diarrhoea (often bloody), and abdominal pain (which may mimic appendicitis).
Q: How is Campylobacter infection generally managed?
A: It is usually self-limiting, but antibiotics are recommended for severe cases or in immunocompromised patients.
Q: What is the first-line antibiotic for severe Campylobacter infection?
A: Clarithromycin.
Q: What is an alternative antibiotic to clarithromycin for Campylobacter infection?
A: Ciprofloxacin, although strains with decreased sensitivity to ciprofloxacin are common.
Q: What are the possible complications of Campylobacter infection?
A: Guillain-Barré syndrome, reactive arthritis, septicaemia, endocarditis, and arthritis.
Q: What is the causative organism of cat scratch disease?
A: Bartonella henselae, a Gram-negative rod.
Q: What are the common features of cat scratch disease?
A: Fever, history of a cat scratch, regional lymphadenopathy, headache, and malaise.
Q: What is the most common causative organism of cellulitis?
A: Streptococcus pyogenes.
Q: What are the common features of cellulitis?
A: Erythema, swelling, systemic upset, fever, malaise, and nausea. It often occurs on the shins and is usually unilateral.
Q: How is cellulitis diagnosed?
A: The diagnosis of cellulitis is clinical; no further investigations are required in primary care.
Q: When are blood tests or blood cultures requested for cellulitis?
A: Bloods and blood cultures may be requested if the patient is admitted and sepsis is suspected.
Q: What is the Eron classification system used for?
A: It is used to guide the management and admission criteria for cellulitis.
Q: What are the criteria for Eron Class I cellulitis?
A: No signs of systemic toxicity, no uncontrolled co-morbidities.
Q: What are the criteria for Eron Class II cellulitis?
A: The person is systemically unwell or systemically well but has a co-morbidity (e.g., peripheral arterial disease or chronic venous insufficiency).
Q: What are the criteria for Eron Class III cellulitis?
A: The person has significant systemic upset (e.g., acute confusion, tachycardia, hypotension) or a limb-threatening infection due to vascular compromise.
Q: What are the criteria for Eron Class IV cellulitis?
A: The person has sepsis syndrome or a life-threatening infection (e.g., necrotizing fasciitis).
Q: What is the recommended treatment for Eron Class I cellulitis?
A: Oral flucloxacillin as first-line treatment; oral clarithromycin, erythromycin (in pregnancy), or doxycycline if allergic to penicillin.
Q: How is Eron Class II cellulitis managed?
A: Admission may not be necessary if intravenous antibiotics and monitoring can be managed in the community; otherwise, oral antibiotics.
Q: What is the management for Eron Class III-IV cellulitis?
A: Admission for intravenous antibiotics, with options like co-amoxiclav, clindamycin, cefuroxime, or ceftriaxone.
Q: What is the causative organism of chancroid?
A: Haemophilus ducreyi.
Q: What are the typical features of chancroid?
A: Painful genital ulcers with sharply defined, ragged, undermined borders and unilateral, painful inguinal lymph node enlargement.
singular ulcer
Q: What groups are at increased risk of severe varicella (chickenpox)?
A: Immunosuppressed patients, neonates, and pregnant women.
Q: What are the criteria for post-exposure prophylaxis for varicella?
A: 1. Significant exposure to chickenpox or herpes zoster. 2. A clinical condition that increases the risk of severe varicella. 3. No antibodies to the varicella virus.
Q: What is the recommended post-exposure prophylaxis for at-risk individuals who meet the criteria?
A: Varicella-zoster immunoglobulin (VZIG).
Q: When should varicella-zoster immunoglobulin (VZIG) be administered after exposure?
A: Ideally within 7 days of exposure.
Q: Why is blood testing for varicella antibodies important in at-risk exposed patients?
A: To confirm the absence of antibodies to varicella before administering post-exposure prophylaxis.
Q: What is the most prevalent sexually transmitted infection in the UK?
A: Chlamydia, caused by Chlamydia trachomatis.
Q: What are common symptoms of Chlamydia in women?
A: Cervicitis (discharge, bleeding), dysuria.
Q: What are common symptoms of Chlamydia in men?
A: Urethral discharge, dysuria.
Q: What are potential complications of untreated Chlamydia?
A: Epididymitis, pelvic inflammatory disease, endometritis, ectopic pregnancies, infertility, reactive arthritis, and Fitz-Hugh-Curtis syndrome.
Q: What is the investigation of choice for Chlamydia?
A: Nuclear acid amplification tests (NAATs).
Q: What is the first-line investigation for men with suspected Chlamydia?
A: First-void urine sample.
Q: What is the first-line investigation for women with suspected Chlamydia?
A: Vulvovaginal swab.
Q: What is the first-line treatment for Chlamydia?
A: Doxycycline (7-day course).
Q: What alternative treatment for Chlamydia is recommended if doxycycline is contraindicated or not tolerated?
A: Azithromycin (1g once, then 500mg daily for 2 days).
Q: What is the preferred treatment for pregnant women with Chlamydia?
A: Azithromycin, erythromycin, or amoxicillin.
Q: How should Chlamydia contacts be treated?
A: Contacts should be offered treatment before the results of their investigations are known.
Q: What bacteria causes Cholera?
A: Vibrio cholerae, a Gram-negative bacteria.
Q: What is a characteristic feature of Cholera?
A: Profuse ‘rice water’ diarrhoea.
Q: What are common complications of Cholera?
A: Dehydration and hypoglycaemia.
Q: What is the primary management for Cholera?
A: Oral rehydration therapy.
Q: What antibiotics can be used to treat Cholera?
A: Doxycycline or ciprofloxacin.
Q: What are the Gram-positive cocci?
A: Staphylococci, Streptococci (including Enterococci).
Q: What are the Gram-negative cocci?
A: Neisseria meningitidis, Neisseria gonorrhoeae, Moraxella catarrhalis.
Q: What is the mnemonic to remember Gram-positive rods?
A: ABCD L - Actinomyces, Bacillus anthracis, Clostridium, Diphtheria (Corynebacterium diphtheriae), Listeria monocytogenes.
Q: Which organisms are Gram-negative rods?
A: Escherichia coli, Haemophilus influenzae, Pseudomonas aeruginosa, Salmonella spp., Shigella spp., Campylobacter jejuni.
Q: What are Clostridia?
A: Gram-positive, obligate anaerobic bacilli.
Q: What does Clostridium perfringens produce, and what does it cause?
A: Produces α-toxin (lecithinase) which causes gas gangrene (myonecrosis) and haemolysis. Features include tender, oedematous skin with haemorrhagic blebs and bullae, and crepitus on palpation.
Q: What is the effect of Clostridium botulinum?
A: Prevents acetylcholine release leading to flaccid paralysis. Typically seen in canned foods and honey.
Q: What does Clostridium difficile cause and produce?
A: Causes pseudomembranous colitis, typically after broad-spectrum antibiotic use. Produces an exotoxin and a cytotoxin.
Q: What does Clostridium tetani produce, and what is its effect?
A: Produces the exotoxin tetanospasmin, which prevents the release of glycine from Renshaw cells in the spinal cord, causing spastic paralysis.
Q: What is Cryptosporidiosis, and what species cause it?
A: Cryptosporidiosis is the commonest protozoal cause of diarrhoea in the UK. It is caused by Cryptosporidium hominis and Cryptosporidium parvum.
Q: In which patients is Cryptosporidiosis more common?
A: It is more common in immunocompromised patients (e.g., HIV) and young children.
Q: What are the features of Cryptosporidiosis?
A: Watery diarrhoea, abdominal cramps, fever. In immunocompromised patients, the entire gastrointestinal tract may be affected, leading to complications like sclerosing cholangitis and pancreatitis.
Q: How is Cryptosporidiosis diagnosed?
A: Stool examination using modified Ziehl-Neelsen stain (acid-fast stain) to reveal the characteristic red cysts of Cryptosporidium.
Q: What is the management for Cryptosporidiosis?
A: Supportive treatment for immunocompetent patients. For HIV patients, starting antiretroviral therapy often resolves the infection. Nitazoxanide or rifaximin may be used for immunocompromised patients or severe cases.
Q: What is Cutaneous Larva Migrans, and what causes it?
A: Cutaneous larva migrans is a dermatological condition caused by the cutaneous penetration and migration of nematode larvae, primarily from the Ancylostoma genus (e.g., Ancylostoma braziliense).
Q: How is Cutaneous Larva Migrans transmitted?
A: It is transmitted via faecal-contaminated soil or sand, with significant risk for individuals who have had barefoot beach visits or direct soil contact.
Q: What is the clinical presentation of Cutaneous Larva Migrans?
A: An intensely pruritic, ‘creeping’, serpiginous, erythematous cutaneous eruption that advances over time. It can last for weeks to months and may lead to secondary bacterial infection due to excessive scratching.
Q: How is Cutaneous Larva Migrans diagnosed?
A: Diagnosis is typically clinical, based on the patient’s exposure history and characteristic skin manifestations.
Q: What are the treatment options for Cutaneous Larva Migrans?
A: Anthelmintic agents like ivermectin or albendazole are used. Topical thiabendazole can be effective but is generally less preferred due to lower efficacy and higher side effects.
Q: What are the prevention strategies for Cutaneous Larva Migrans?
A: Preventive strategies include avoiding direct skin contact with potentially contaminated soil, patient education on protective measures, and public health measures to control animal defecation.
Q: What is Cytomegalovirus (CMV)?
A: CMV is a herpes virus that affects mainly immunocompromised individuals, such as those with HIV or those on immunosuppressants following organ transplantation.
Q: What is the characteristic appearance of infected cells in CMV?
A: Infected cells have an ‘Owl’s eye’ appearance due to intranuclear inclusion bodies.
Q: What are the features of congenital CMV infection?
A: Features include growth retardation, pinpoint petechial ‘blueberry muffin’ skin lesions, microcephaly, sensorineural deafness, encephalitis (seizures), and hepatosplenomegaly.
Q: What is CMV mononucleosis?
A: A mononucleosis-like illness that may develop in immunocompetent individuals, presenting with symptoms like fever, lymphadenopathy, and fatigue.
Q: What is CMV retinitis, and how is it treated?
A: CMV retinitis occurs in HIV patients with a low CD4 count (<50) and presents with blurred vision. Fundoscopy shows retinal haemorrhages and necrosis, often called ‘pizza’ retina. Treatment is IV ganciclovir.
Q: What is CMV encephalopathy?
A: CMV encephalopathy is seen in HIV patients with low CD4 counts and can lead to neurological symptoms, including altered consciousness and seizures.
Q: What are the clinical features of Dengue fever?
A: Features include fever, headache (often retro-orbital), myalgia, bone pain, arthralgia (“break-bone fever”), pleuritic pain, facial flushing, maculopapular rash, and haemorrhagic manifestations such as positive tourniquet test, petechiae, purpura/ecchymosis, and epistaxis.
Q: What are the “warning signs” in Dengue fever?
A: Warning signs include abdominal pain, hepatomegaly, persistent vomiting, and clinical fluid accumulation (ascites, pleural effusion).
Q: What characterizes severe Dengue (dengue haemorrhagic fever)?
A: Severe Dengue involves disseminated intravascular coagulation (DIC) with thrombocytopenia, spontaneous bleeding, and can lead to dengue shock syndrome (DSS) in 20-30% of cases.
Q: What are the common investigations for Dengue fever?
A: Common investigations include blood tests showing leukopenia, thrombocytopenia, and raised aminotransferases, along with serology, nucleic acid amplification tests for viral RNA, and NS1 antigen test.
Q: What is the treatment for Dengue fever?
A: Treatment is symptomatic, involving fluid resuscitation and blood transfusion as needed. No antiviral treatments are currently available.
Q: What causes Diphtheria?
A: Diphtheria is caused by the Gram-positive bacterium Corynebacterium diphtheriae.
Q: What is the typical presentation of Diphtheria?
A: Features include sore throat with a grey, pseudomembrane on the posterior pharyngeal wall (diphtheric membrane), bulky cervical lymphadenopathy, a “bull neck” appearance, neuritis (e.g. cranial nerves), and heart block. Recent visitors to Eastern Europe/Russia/Asia may be at higher risk.
Q: What are the possible complications of Diphtheria?
A: Complications include necrosis of myocardial, neural, and renal tissue due to the systemic distribution of the diphtheria toxin.
Q: How is Diphtheria diagnosed?
A: Diagnosis is made through culture of a throat swab using tellurite agar or Loeffler’s media.
Q: What is the management for Diphtheria?
A: Treatment involves intramuscular penicillin and diphtheria antitoxin.
Q: How is Ebola virus transmitted?
A: Ebola spreads through human-to-human transmission via direct contact with blood, secretions, organs, or other bodily fluids of infected people, and with contaminated surfaces and materials.
Q: What are the early symptoms of Ebola?
A: Early symptoms include sudden onset of fever, fatigue, muscle pain, headache, and sore throat.
Q: What are some later symptoms of Ebola?
A: Later symptoms include vomiting, diarrhoea, rash, impaired kidney and liver function, and both internal and external bleeding.
Q: Who should be considered for Ebola virus in primary care?
A: Ebola should be suspected in patients with a fever of 37.5°C or a history of fever in the past 24 hours who have recently visited affected areas or have had contact with the body fluids of an infected person or laboratory animal.
Q: How should a patient suspected of having Ebola be managed in primary care?
A: The patient should be isolated in a single room, and physical contact should be avoided. Public Health England (PHE) should be contacted for further advice.
Q: What causes enteric fever (typhoid and paratyphoid)?
A: Enteric fever is caused by Salmonella typhi (typhoid) and Salmonella paratyphi (paratyphoid).
Q: How is typhoid fever transmitted?
A: Typhoid fever is transmitted via the faecal-oral route, often through contaminated food and water.
Q: What are the common symptoms of typhoid fever?
A: Symptoms include headache, fever, arthralgia, abdominal pain, distension, and constipation.
Q: What is relative bradycardia and when is it seen?
A: Relative bradycardia is a slower-than-expected heart rate for the degree of fever and is seen in typhoid fever.
Q: What are rose spots and in which type of fever are they more common?
A: Rose spots are small, blanching, pink macules that appear on the trunk in 40% of patients with enteric fever, and are more common in paratyphoid.
Q: What are the potential complications of typhoid fever?
A: Potential complications include osteomyelitis (especially in sickle cell disease), GI bleeding/perforation, meningitis, cholecystitis, and chronic carriage (especially in adult females).
Q: Which pathogen is a common cause of osteomyelitis in sickle cell disease?
A: Salmonella is a common cause of osteomyelitis in sickle cell disease.
Q: What type of viruses are enteroviruses?
A: Enteroviruses are positive-sense, single-stranded RNA viruses.
Q: Which viruses are included in the enterovirus family?
A: The enterovirus family includes Coxsackievirus, echovirus, and rhinovirus, among others.
Q: What is the most common cause of viral meningitis in the adult population?
A: Enteroviruses are the most common cause of viral meningitis in adults.
Q: What diseases are caused by enteroviruses?
A: Enteroviruses can cause a wide range of diseases, including Hand, Foot and Mouth disease, herpangina, and pericarditis.
Q: What is Hand, Foot and Mouth disease and which virus causes it?
A: Hand, Foot and Mouth disease is a viral infection characterized by rash and sores on the hands, feet, and mouth, commonly caused by enteroviruses, particularly Coxsackievirus.
Q: What malignancies are associated with Epstein-Barr virus (EBV) infection?
A: The malignancies associated with EBV infection include Burkitt’s lymphoma, Hodgkin’s lymphoma, nasopharyngeal carcinoma, and HIV-associated central nervous system lymphomas.
Q: What non-malignant condition is associated with Epstein-Barr virus (EBV) infection?
A: The non-malignant condition associated with EBV infection is hairy leukoplakia.
Q: What type of Burkitt’s lymphoma is associated with Epstein-Barr virus (EBV)?
A: EBV is associated with both African and sporadic Burkitt’s lymphoma.
Q: What type of bacteria is Escherichia coli (E. coli)?
A: Escherichia coli is a facultative anaerobic, lactose-fermenting, Gram-negative rod.
Q: What diseases can Escherichia coli infections cause in humans?
A: E. coli infections can lead to diarrhoeal illnesses, urinary tract infections (UTIs), and neonatal meningitis.
Q: What is E. coli O157:H7 known for?
A: E. coli O157:H7 is associated with severe, haemorrhagic, watery diarrhoea, high mortality, and complications such as haemolytic uraemic syndrome. It is often spread by contaminated ground beef.
Q: What defines travellers’ diarrhoea?
A: Travellers’ diarrhoea is defined as at least 3 loose to watery stools in 24 hours with or without abdominal cramps, fever, nausea, vomiting, or blood in the stool.
Q: What is the most common cause of travellers’ diarrhoea?
A: The most common cause of travellers’ diarrhoea is Escherichia coli.
Q: What causes acute food poisoning?
A: Acute food poisoning is typically caused by Staphylococcus aureus, Bacillus cereus, or Clostridium perfringens.
Q: What are the typical presentations for different gastroenteritis infections?
Escherichia coli: Common amongst travellers, watery stools, abdominal cramps, nausea
Giardiasis: Prolonged, non-bloody diarrhoea
Cholera: Profuse, watery diarrhoea, severe dehydration, weight loss
Shigella: Bloody diarrhoea, vomiting, abdominal pain
Staphylococcus aureus: Severe vomiting, short incubation period
Campylobacter: Flu-like prodrome, crampy abdominal pains, fever, bloody diarrhoea, complications like Guillain-Barre syndrome
Bacillus cereus: Vomiting within 6 hours (due to rice) or diarrhoeal illness after 6 hours
Amoebiasis: Gradual onset bloody diarrhoea, abdominal pain, tenderness lasting several weeks
Q: What are the typical features of genital herpes?
A: Painful genital ulceration, dysuria, pruritus, more severe primary infection, systemic features like headache, fever, malaise, tender inguinal lymphadenopathy, urinary retention.
Q: How does the severity of primary genital herpes compare to recurrent episodes?
A: The primary infection is often more severe than recurrent episodes.
Q: What are the investigations of choice for genital herpes?
A: Nucleic acid amplification tests (NAAT), considered superior to viral culture. HSV serology may be useful for recurrent genital ulceration of unknown cause.
Q: What are the general management measures for genital herpes?
A: Saline bathing, analgesia, topical anaesthetic agents like lidocaine, oral aciclovir, and long-term aciclovir for frequent exacerbations.
Q: What is the recommended management for genital herpes during pregnancy?
A: Elective caesarean section is advised if a primary attack occurs after 28 weeks gestation. Women with recurrent herpes should receive suppressive therapy, as the risk of transmission to the baby is low.
Q: What causes genital warts?
A: Genital warts are caused by human papillomavirus (HPV), especially types 6 and 11.
Q: Which HPV types are associated with an increased risk of cervical cancer?
A: HPV types 16, 18, and 33.
Q: What are the typical features of genital warts?
A: Small (2-5 mm) fleshy protuberances, slightly pigmented, may bleed or itch.
Q: What are the first-line treatments for genital warts?
A: Topical podophyllum or cryotherapy, depending on the location and type of lesion.
Q: How are multiple, non-keratinised genital warts treated?
A: They are generally best treated with topical agents.
Q: How are solitary, keratinised genital warts treated?
A: They respond better to cryotherapy.
Q: What is the second-line treatment for genital warts?
A: Imiquimod, a topical cream.
Q: What causes giardiasis?
A: Giardiasis is caused by the flagellate protozoan Giardia lamblia.
Q: How is giardiasis spread?
A: Giardiasis is spread by the faeco-oral route.
Q: What are the risk factors for giardiasis?
A: Foreign travel, swimming or drinking water from a river or lake, and male-male sexual contact.
Q: What are the common features of giardiasis?
A: Often asymptomatic, non-bloody diarrhoea, steatorrhoea, bloating, abdominal pain, lethargy, flatulence, weight loss, malabsorption, and lactose intolerance.
Q: How is giardiasis diagnosed?
A: Stool microscopy for trophozoite and cysts (sensitivity around 65%), stool antigen detection assay (greater sensitivity and faster turn-around time), and PCR assays.
Q: What is the treatment for giardiasis?
A: Treatment is with metronidazole.
Q: What causes gonorrhoea?
A: Gonorrhoea is caused by the Gram-negative diplococcus Neisseria gonorrhoeae.
Q: What are the common features of gonorrhoea in males?
A: Urethral discharge and dysuria.
Q: What are the common features of gonorrhoea in females?
A: Cervicitis, leading to vaginal discharge.
Q: What are the common features of rectal and pharyngeal gonorrhoea?
A: Rectal and pharyngeal infections are usually asymptomatic.
Q: What are the local complications of gonorrhoea?
A: Urethral strictures, epididymitis, and salpingitis, which can lead to infertility.
Q: What is the treatment for gonorrhoea?
A: The current first-line treatment is a single dose of IM ceftriaxone 1g. If sensitivities are known, a single dose of oral ciprofloxacin 500mg can be used.
Q: What are the key features of disseminated gonococcal infection (DGI)?
A: Tenosynovitis, migratory polyarthritis, and dermatitis (maculopapular or vesicular lesions).
Q: What complications can arise from disseminated gonococcal infection?
A: Septic arthritis, endocarditis, and perihepatitis (Fitz-Hugh-Curtis syndrome).
Q: What is the incubation period for hepatitis A?
A: The incubation period for hepatitis A is 2-4 weeks.
Q: How is hepatitis A transmitted?
A: Hepatitis A is transmitted via faecal-oral spread, often in institutions.
Q: Does hepatitis A cause chronic disease?
A: No, hepatitis A does not cause chronic disease.
Q: What are the common features of hepatitis A?
A: Flu-like prodrome, right upper quadrant abdominal pain, tender hepatomegaly, jaundice, and deranged liver function tests.
Q: Is there a vaccine for hepatitis A?
A: Yes, there is an effective vaccine for hepatitis A.
Q: Who should be vaccinated against hepatitis A?
A: Those travelling to or residing in areas of high or intermediate prevalence, people with chronic liver disease, patients with haemophilia, men who have sex with men, injecting drug users, individuals at occupational risk (e.g. lab workers, sewage workers, and those working with primates).
Q: How is hepatitis B transmitted?
A: Hepatitis B is spread through exposure to infected blood or body fluids, including vertical transmission from mother to child.
Q: What is the incubation period for hepatitis B?
A: The incubation period for hepatitis B is 6-20 weeks.
Q: What are the common features of hepatitis B infection?
A: Fever, jaundice, and elevated liver transaminases.
Q: What are the complications of hepatitis B infection?
A: Chronic hepatitis (5-10%), fulminant liver failure (1%), hepatocellular carcinoma, glomerulonephritis, polyarteritis nodosa, and cryoglobulinaemia.
Q: What is the routine vaccination schedule for hepatitis B in the UK?
A: Children born in the UK are vaccinated at 2, 3, and 4 months of age.
Q: Who should be vaccinated against hepatitis B?
A: Healthcare workers, intravenous drug users, sex workers, close family contacts of an individual with hepatitis B, individuals receiving regular blood transfusions, chronic kidney disease patients, prisoners, and chronic liver disease patients.
Q: When should anti-HBs levels be tested?
A: Testing for anti-HBs is recommended for healthcare workers and patients with chronic kidney disease, 1-4 months after primary immunisation.
Q: What treatments are available for hepatitis B?
A: Pegylated interferon-alpha, tenofovir, entecavir, and telbivudine (a synthetic thymidine nucleoside analogue).
Q: What are the at-risk groups for hepatitis C infection?
A: Intravenous drug users, patients who received a blood transfusion prior to 1991 (e.g., haemophiliacs).
Q: What are the CSF findings in bacterial meningitis?
A: In bacterial meningitis, the CSF is cloudy, glucose is low (< 1/2 plasma), protein is high (> 1 g/l), and white cells are between 10 - 5,000 polymorphs/mm³.
Q: What are the CSF findings in viral meningitis?
A: In viral meningitis, the CSF is clear/cloudy, glucose is 60-80% of plasma glucose, protein is normal or raised, and white cells are between 15 - 1,000 lymphocytes/mm³.
Q: What are the CSF findings in tuberculous meningitis?
A: In tuberculous meningitis, the CSF is slightly cloudy with a fibrin web, glucose is low (< 1/2 plasma), protein is high (> 1 g/l), and white cells are between 30 - 300 lymphocytes/mm³.
Q: What are the CSF findings in fungal meningitis?
A: In fungal meningitis, the CSF is cloudy, glucose is low, protein is high, and white cells are between 20 - 200 lymphocytes/mm³.
