Amebiasis is caused by which parasite?

Prepare for the Certificate in Public Health Inspection exam. Utilize our flashcards and multiple-choice questions, each featuring hints and explanations. Ensure your success with our comprehensive resources!

Amebiasis is caused by Entamoeba histolytica, a pathogenic intestinal protozoan. It lives as cysts in contaminated water or food and as invasive trophozoites in the colon, capable of penetrating the mucosa and causing ulceration, dysentery, and, if spread via the bloodstream, liver abscess. This organism is distinct from the others listed: Giardia lamblia causes giardiasis with greasy, malabsorption-type diarrhea; Cryptosporidium parvum causes cryptosporidiosis with watery diarrhea, especially problematic in immunocompromised individuals; Toxoplasma gondii causes toxoplasmosis, often acquired from undercooked meat or cat feces and not associated with amebic colitis. Therefore, Entamoeba histolytica is the agent responsible for amebiasis.