Heterophyes Infection [Heterophyiasis]
Heterophyes Infection is an endemic infectious disease caused by the trematode known as Heterophyes heterophyes, a very small intestinal flatworm or fluke. It is common in Far East, Middle East, and Egypt. Infection spreads through eating infected raw or undercooked fish from freshwater or brackish water containing metacercariae (encysted stage).
The worm attaches to Middle and upper portion of jejunum and duodenum of the small intestine. The infection causes swelling and dead columnar epithelial cells of small intestine. Initially it causes gastrointestinal symptoms such as epigastric pain, indigestion, and abdominal discomfort, and severe diarrhea, abdominal pain, and vomiting. Praziquantel is the first choice of the drug.
A considerable quantity of freshwater fish and shellfish is imported into UK from endemic countries in Southeast Asia. Some of these products are imported fresh or processed in such a way that the infective metacercariae may not be destroyed. Further, current inspection procedures in UK may not detect the presence of all parasites in imported fish products. Therefore, there may be a risk of infection if the fish or shellfish is consumed raw or lightly cooked.