Giardia lamblia as an intestinal pathogen

Abstract

Giardia lamblia are protozoan parasites which cause human intestinal disease. The life cycle has a multiplying intraduode- nal trophozoite and an excreted cyst. Infection occurs after cyst ingestion from faecally contaminated water or by direct faecal-oral transmission in situations of poor sanitary standards. but the zoonotic nature of giardiasis is debated. The pathophysiology may arise from enzyme or active transport deficiencies, synergy with intestinal bacteria or an immuno- pathological process. Diagnosis is made by microscopic identification of cysts or trophozoites in small bowel samples or faeces. Symptoms arc acute with diarrhoea (without blood), abdominal cramps, bloating and flatulence. The treatment of choice is either metronidazole or tinidazole. No vaccine or drug prophylaxis exists, and measures to avoid cyst ingestion should be undertaken. © 1992 S. Karger AG, Basel.