Relationship between snail population density and infection status of snails and fish with zoonotic trematodes in Vietnamese carp nurseries.

Background: Fish-borne zoonotic trematodes (FZT) are a food safety and health concern in Vietnam. Humans and other final hosts acquire these parasites from eating raw or under-cooked fish with FZT metacercariae. Fish raised in ponds are exposed to cercariae shed by snail hosts that are common in fish farm ponds.