AMC MCQ AMC MCQ - Australian Medical Council Multiple Choice Questions Infectious Diseases and Immunology Questions and Answers 3

Question 1

A 30-year-old presents with ascending paralysis 2 weeks after a diarrheal illness caused by Campylobacter jejuni. Nerve conduction studies show demyelination. What is the diagnosis?

Accepted Answer

Guillain-Barré syndrome

Answer

Multiple sclerosis

Answer

Transverse myelitis

Answer

Botulism

Question 2

Which test is most sensitive for the diagnosis of active tuberculosis in a sputum sample?

Accepted Answer

Mycobacterial culture

Answer

Tuberculin skin test (Mantoux)

Answer

Ziehl-Neelsen stain

Answer

Interferon-gamma release assay (IGRA)

Question 3

A 50-year-old farmer presents with fever, headache, myalgia, and a 'rose-thorn' eschar after a tick bite in rural Queensland. Which organism is responsible?

Accepted Answer

Rickettsia australis

Answer

Borrelia burgdorferi

Answer

Coxiella burnetii

Answer

Anaplasma phagocytophilum

Question 4

A patient with X-linked agammaglobulinemia (Bruton's disease) would be most susceptible to which type of infection?

Accepted Answer

Encapsulated bacterial infections

Answer

Intracellular viral infections

Answer

Fungal infections

Answer

Parasitic infections

Question 5

A 35-year-old sex worker presents with a painless indurated genital ulcer with rubbery inguinal lymph nodes. Dark-field microscopy shows spirochetes. What is the first-line treatment?

Accepted Answer

Benzathine penicillin G 2.4 million units IM once

Answer

Azithromycin 1 g orally once

Answer

Doxycycline 100 mg twice daily for 14 days

Answer

Ceftriaxone 250 mg IM once

Question 6

Which mechanism allows Staphylococcus aureus to resist beta-lactam antibiotics in MRSA?

Accepted Answer

Altered penicillin-binding protein (PBP2a) encoded by mecA gene

Answer

Production of extended-spectrum beta-lactamase (ESBL)

Answer

Efflux pump overexpression

Answer

Outer membrane impermeability