AMC MCQ AMC MCQ - Australian Medical Council Multiple Choice Questions Infectious Diseases and Immunology Questions and Answers 1 — Questions and Answers
Question 1: A 28-year-old traveler returns from Southeast Asia with fever, chills, and rigors every 48 hours. Blood film shows ring forms and banana-shaped gametocytes. Which Plasmodium species is most likely responsible?
- Plasmodium vivax
- Plasmodium malariae
- Plasmodium falciparum (Correct answer)
- Plasmodium ovale
Correct answer: Plasmodium falciparum
Plasmodium falciparum produces banana-shaped (crescent) gametocytes and is the most dangerous malaria species.
Question 2: A 35-year-old HIV-positive patient with CD4 count of 80 cells/µL presents with headache, fever, and meningismus. India ink stain of CSF shows encapsulated yeast. What is the most appropriate treatment?
- Fluconazole alone
- Amphotericin B plus flucytosine (Correct answer)
- Caspofungin
- Voriconazole
Correct answer: Amphotericin B plus flucytosine
Cryptococcal meningitis in immunocompromised patients is treated with induction therapy using amphotericin B plus flucytosine.
Question 3: Which organism is the most common cause of community-acquired pneumonia requiring hospitalization in adults?
- Mycoplasma pneumoniae
- Haemophilus influenzae
- Streptococcus pneumoniae (Correct answer)
- Legionella pneumophila
Correct answer: Streptococcus pneumoniae
Streptococcus pneumoniae remains the most common cause of community-acquired pneumonia requiring hospitalization.
Question 4: A 22-year-old presents with painful genital ulcers and bilateral inguinal lymphadenopathy. PCR confirms herpes simplex virus type 2. What is the first-line treatment?
- Valacyclovir (Correct answer)
- Foscarnet
- Cidofovir
- Ganciclovir
Correct answer: Valacyclovir
Valacyclovir (or acyclovir) is first-line therapy for primary genital herpes simplex infection.
Question 5: A patient with systemic lupus erythematosus has low C3 and C4 levels. Which component of the immune system is primarily responsible for this finding during active disease?
- Natural killer cell activation
- Complement consumption via immune complex deposition (Correct answer)
- T-cell mediated cytotoxicity
- Mast cell degranulation
Correct answer: Complement consumption via immune complex deposition
In SLE, immune complexes deposit in tissues and activate the classical complement pathway, consuming C3 and C4.
Question 6: A 45-year-old immunocompromised patient develops a vesicular rash in a dermatomal distribution with severe pain. Which antiviral should be started within 72 hours?
- Oseltamivir
- Ribavirin
- Valacyclovir (Correct answer)
- Lamivudine
Correct answer: Valacyclovir
Valacyclovir started within 72 hours of herpes zoster onset reduces duration and severity, including post-herpetic neuralgia.
AMC MCQ AMC MCQ - Australian Medical Council Multiple Choice Questions Infectious Diseases and Immunology Questions and Answers 1
A 28-year-old traveler returns from Southeast Asia with fever, chills, and rigors every 48 hours.
Blood film shows ring forms and banana-shaped gametocytes.
Which Plasmodium species is most likely responsible?