Health topics

Foodborne trematodiases


Foodborne trematode (FBT) infections, taeniasis and cysticercosis are noteworthy neglected tropical diseases. They are caused by trematodes (flatworms or “flukes”) or pork tapeworms. People become infected through the consumption of raw or poorly cooked freshwater fish (clonorchiasis and opisthorchiasis), crustaceans (fascioliasis) and vegetables (paragonimiasis) that are acquired through ingestion of food contaminated with the larval stages, eggs or proglottids of the parasite.

The WHO Western Pacific Region presents the second largest burden of foodborne diseases and the highest mortality due to foodborne parasites in the world, according to the recent WHO estimates of the global burden of foodborne diseases released in 2015. Of particular public health concern in the Region are foodborne trematode infections, including liver fluke infections (clonorchiasis and opisthorchiasis), fascioliasis and paragonimiasis, and taeniasis/cysticercosis (pork tapeworm). Liver flukes are classified as carcinogenic, long-term infections causing cholangiocarcinoma or bile duct cancer, and cysticercosis, particularly neurocysticercosis, is known to cause epilepsy and sometimes death.

Transmission is linked to practices in producing, processing and preparing foods and livestock. These diseases are also zoonotic infections affecting domestic or wild animals. Therefore, strong inter-sectoral cooperation is required for control of their transmission.