Amebiasis

Abstract

AMEBIASIS, infection with the small protozoan parasite Entamoeba histolytica, is present throughout the world. It is usually asymptomatic (commensal), but may produce dysentery, an intestinal mass lesion or extraintestinal lesions, particularly abscess of the liver.Two forms of the parasite are found in stool specimens: the cyst form (10 to 20 μm in external diameter) is predominant in formed specimens, and the actively motile trophozoite form (12 to 50 μm) in the mucoid and bloody stools of patients with symptomatic intestinal amebiasis. E. histolytica cysts passed in the stool are immediately infectious for others. Infection results only from ingestion of . . .