Trematode species, such as Spirorchis parvus, are pathogenic, and adult flukes live in blood vessels and the heart where they lay eggs. Widespread deposition of eggs in blood vessels can cause blockage of small vessels leading to tissue ischemia and necrosis. Spirorchis parvus can also invade various tissues.

Where are trematodes found?

Human infections are most common in Asia, Africa and Latin America. However, trematodes can be found anywhere where untreated human waste is used as fertilizer.

Where do flukes live in humans?

Few flukes (Fasciola hepatica) live on the gills, skin, or outside of their hosts, while others, like blood flukes (Schistosoma), live inside their hosts. Humans are infected by Fasciola hepatica when raw or improperly cooked food is ingested.