Preliminary investigation in the Metorchis taiwanensis infection in basin of Huaihe River

To determine whether the Metorchis taiwanensis infection is prevalent in basin of Huaihe River and its characteristics of breeding,the eggs of M.taiwanensis in dung of ducks were collected by method of sedimentation,and the rediae and cercariae in Parafossarulus striatulus were isolated by tabletting and microscopic examination.The encysted metacercaria in Pseudorasbora parve were isolated by tabletting,washing,sedimentation,microscopic examination and artificial infection of brood ducks,and the adult worms in common bile duct and hepatic duct brought from fishmen and the experimental brood ducks were isolated after dissection.It was found the average positive rate of eggs of M.tanwanensis in stool of ducks was 18.87%(151/800);that of rediae and cercarriae in P.striatulus was 1.08%(13/1200).and that of encysted metacercaria in P.parve was 12.5%(20/160).Meanwhile,the positive rate of adult worms in common bile duct and hepatic duct of ducks was 22.5%(18/80).The adult worms could be isolated in liver of ducklines infected by encysted metacercaria.It is evident from the investigation performed in the present study that M.tanwanesis infection is prevalent in Huaihe River and it can be bred in P.striatulus,P.parve and brood ducks.