한국산 재첩이 이전고환극구흡충의 제2패류중간숙주가 될 수 있는가?

초록

This study was aimed to confirm natural infection of C. fluminea collected from various localities with Echinostoma cinetorchis, an important human intestinal fluke in Korea. In field-collected C. fluminea(about 2.4cm in width), no shedding of lophocercous cercariae and metacercariae of E. cinetorchis was found in this study. As the second step, each of a total 20 clams was exposed to 20 E. cinetorchis miracidia for 20 hrs in the laboratory, and the exposed clams was checked for shedding the cercariae everyday from 10 days postinfection. However, no cercaria was released up to 50 days after observation. To confirm the clams as the second intermediate host of E. cinetorchis experimentally, each of 30 clams was exposed to 100 cercariae shed from Segmentina hemisphaerula which had been infected with miracidia of E. cinetorchis. More than 90% of 30 clams employed were found to be infected with the metacercariae. Metacercariae from clams were orally fed to rats(Sprague-Dawley strain). These rats were killed 4 weeks after infection and typical adult worms of E. cinetorchis were recovered from the small intestines. This is the first report that C. fluminea, a Korean favorable food source, possibly act as the second intermediate host of E. cinetorchis in Korea.