skip to main content

Giardiasis — DTM&H MCQ

Instant feedback + full explanation. One question, done properly.

EasyProtozoal InfectionsGiardiasisDTM&H

A 23-year-old backpacker returns from India with a 10-day history of watery diarrhoea, bloating, and foul-smelling flatulence. Stool microscopy shows pear-shaped flagellated trophozoites and oval cysts. What is the most appropriate treatment?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: A — Metronidazole 400 mg three times daily for 5 days

Pear-shaped flagellated trophozoites and oval cysts are diagnostic of Giardia lamblia. Metronidazole is first-line treatment for giardiasis. Tinidazole (single 2 g dose) is an effective alternative with better compliance. Nitazoxanide is an option but less commonly used. Ciprofloxacin treats bacterial diarrhoea. Albendazole has some activity against Giardia but is not first-line. Giardia is the most common protozoal cause of travellers' diarrhoea.

Reference: WHO; BNF; Manson's Tropical Diseases