Abstract:

Objective To investigate the species of freshwater snails, crabs and their natural infection of Paragonimus cercaria, metacercariae in northern suburban of Guangzhou, and understand the distribution of Paragonimus. Methods The freshwater snails and crabs were collected from mountain streams to detect the
cercaria and metacercariae of Paragonimus and their identify categories. Results The average infection rate of cercaria in Liangkou town, Lvtian town (Conghua city) and Nankunshan (Longmen county) was 0.32% , 0.15% and 0.03%, respectively. The snail species in both Liangkou town and Nankunshan was identified as
Semisulcospira libertina, Tricula in Lvtian town. The average infection rate of metacercariae in Liangkou town, Lvtian town and Nankunshan was 100%, 36.73% and 100%, respectively. The crab species in both Liangkou town and Nankunshan were identified as Sinopotamon pinheense, and Nanhaipotomon pinyuanense in Lvtian town. The cercaria and metacercariae were not found in the samples of freshwater snails and crabs in Zengcheng city and Xinfeng County. Conclusions It,s the first report that Liangkou town and Lvtian town of Conghua city in northern suburban of Guangzhou is the ultra-high infectious focus of Paragonimus westermani infection(GradeⅠ), and Nankunshan town is the moderate infectious focus of Paragonimus skrjabini. (Grade Ⅲ).

Key words: Northern suburban of Guangzhou, Freshwater snail, Freshwater crab, Paragonimus, Cercaria, Metacercariae