Intermediate hosts of Paragonimus in the eastern Amazonic region of Ecuador.

A study was done to determine the intermediate hosts of Paragonimus mexicanus (P. peruvianus, P. ecuadoriensis) in the northeastern amazonic region of Ecuador. The first intermediate host belongs to the molluscan family Hydrobiidae, similar to the findings reported in other parts of Latin America. One of 2350 specimens of the hydrobiid snail Aroapyrgus colombiensis examined was found to be naturally infected with rediae containing microcercous cercariae of Paragonimus, this being the first naturally infected first intermediate host reported in Ecuador. The crustacean family, Trichodactylidae, was found as the second intermediate host of paragonimiasis, this being the first time reported in Ecuador. The freshwater crab Zilchiopsis ecuadoriensis was found to be heavily parasitized by Paragonimus metacercariae.