Epidemiology and control of Clonorchiasis sinensis in China.

Clonorchiasis sinensis is a food-borne parasitic zoonosis caused by Clonorchis sinensis which infects fish-eating mammals including humans, dogs, cats and pigs. The disease is prevalent in East Asian and Southeast Asian countries. Boott in 1903 first proved the presence of the disease in China. In 1930s doctors from Europe and America,and Japanese carried out the occasional survey in coastal cities of southeast and northern cities of northeast China respectively. The infective rates ranged from 0.2% to 53.7%. After 1940s Chinese scholars contributed further studies on epidemic investigation and conducted extensive surveys in almost all counties or cities after liberation, especially in the last 30 years. The disease has been reported to be endemic in 24 provinces and municipalities of China, namely, Guangdong, Guangxi, Taiwan, Hainan, Fujian, Zhejiang, Jiangsu, Anhui, Jiangxi, Hubei, Hunan, Sichuan, Guizhou, Yunnan, Henan, Shandong, Shanxi, Hebei, Liaoning, Jilin, Heilongjiang, Beijing, Tianjin and Shanghai (Zuo et al, 1999). Among these two provinces of Guangdong and Guangxi in the south, especially in Zhujiang delta are listed as major endemic areas; Hong Kong, Taiwan, Heilongjiang, Liaoning and Jilin are of minor significance. Moreover, the infection rates among inhabitants in Jiangxi, Hubei, Hunan Provinces of the central-south China increased as the climate and environment are favorable for the first, secondary intermediate and reservoir host of C. sinensis. The epidemiology and control of clonorchiasis in China are reviewed in this paper.