Abstract:

In order to investigate the endemic status of Metorchis orientalis infection in human, mammals, poultries and fishes, an epidemiological survey was performed in randomly selected 5 endemic villages in Pucheng County during 2016-2017. The modified Kato-Katz thick smear method was applied to examine eggs in fecal samples of villagers with over 3-years old. Fresh water fishes were collected from two ponds around villages of Shuidong and Guanjiu and metacercariae were examined in their muscle. The gallbladders were collected from ducks purchased from local market or from dumped wastes and the adult worms were collected and counted. Fecal samples were also collected from cats and dogs and eggs were examined by precipitation concentration and microscopy. Two ducks were each fed with 15 fish (Pseudorasbora parva). The adult worms were collected from gallbladders of the infected ducks and stained with carmine red. Seven people were found infected with M. orientalis from 1 168 subjects examined. The human infection rate in these villagers was 0.6%, 4 of them are males and 3 females with age ranged from 24-83. 190 metacercariae were identified in 340 collected fishes which belonged to 5 species. The infection rate in fish was 60.1% and the P. parva had the highest infection rate of 90.3% (177/196) with average 62 metacercariae infected. 4 out of 15 home-raised ducks were infected and adult worms were identified in their gallbladders. No infection was identified in total examined 50 gallbladders from ducks sold in the market. One each from 14 cat fecal samples and 30 dog fecal samples were infected with M. orientalis. Ten adult worms were collected from two ducks experimentally infected with metacercariae-infested P. parva. The epidemiological survey demonstrated that M. orientalis is endemic in Pucheng County, which infects human, mammals, ducks and fresh water fishes.

Key words: Metorchis orientalis, Infection, Endemic, Pucheng County