Heterophyiasis is infection with the intestinal fluke Heterophyes heterophyes, which is acquired by eating infected raw or undercooked fish from freshwater or brackish water.
Heterophyes heterophyes and several related trematodes are endemic in the Far East, Middle East, and Egypt. Infection is acquired by eating infected raw or undercooked fish from freshwater or brackish water containing metacercariae (encysted stage). After ingestion, metacercariae excyst and attach to the mucosa of the small intestine. There, they develop into adults, growing to about 1.0 to 1.7 mm by 0.3 to 0.4 mm. Salmon live part of their lives in freshwater and can be infected with Nanophyetus salmincola.
Adult flukes can cause abdominal pain and diarrhea. Diagnosis is by finding eggs in the feces. Treatment is with praziquantel 25 mg/kg po tid for 1 day.
Last full review/revision December 2009 by Richard D. Pearson, MD
Content last modified February 2012