Worms

The trematodes are parasitic flatworms, parasites are flat, usually leaf-shaped, with two suction cups, and hermaphrodites, which excluded equistosomas. Trematode parasite infection called. Trematodes have complex life cycles, with the following stages: eggs, embryos or larvae in the water first enters the ciliated maricidio snail, which is the first intermediate host, sporocyst and redia with asexual reproduction in snails, and finally cercaria, which attacks the definitive host , or metaserkaria, achieving both through crops or second intermediate host.

There are many animal trematode infections and infections in humans some derived from them. Most human trematode infections have systemic involvement. Trematode worms that occur in humans are: Fasciola hepatica, Schistosoma, Clonorchis sinensis and Paragonimus opistorquis (westermani, kellicotti, peruvianus, and africanus).