Case definition

Confirmed case

Laboratory confirmation of infection with or without symptoms:

• Positive for E. histolytica by stool antigen ELISA on unpreserved stool samples OR
• Demonstration of E. histolytica trophozoites in intestinal tissue biopsies or ulcer scrapings (e.g., Iron-Haematoxylin [IH] stained smears) OR
• Demonstration of E. histolytica trophozoites in extra-intestinal tissues (e.g., Haematoxylin & Eosin [H&E] stained sections OR
• Demonstration of E. histolytica trophozoites and/or cysts with ingested red blood cells in stool samples OR
• Positive serological test(s) for E. histolytica with clinical evidence of invasive amebiasis. (Invasive amebiasis presents as an acute abscess in the liver, lung, brain or other organs or rarely as a granulomatous lesion in the intestine.) OR 

• Detection of E .histolytica by PCR

Probable case

Laboratory evidence of infection:

• Presence of E. histolytica/dispar cysts and/or trophozoites by microscopy in preserved stool samples with/without symptoms OR
• Positive serological test(s) for E. histolytica without clinical evidence of invasive amebiasis