High prevalence of Clonorchis sinensis infections and coinfection with hepatitis virus in riverside villages in northeast China

In China, the prevalence of Clonorchis sinensis ( C. sinensis ) infections is only evaluated at the provincial level by national sampling surveys, and data from villages and counties are still lacking. In this study, we conducted a cross-sectional survey in 10 villages located along the Lalin River in northeast China. Clonorchiasis was diagnosed using a modified Kato–Katz method that detects the C. sinensis egg in stools. A total of 3,068 persons were screened and 2,911 were recruited for the study. Overall, the prevalence of C. sinensis infection was 29.3%. Among 175 participants who were cured after antiparasitic treatment, 54 (30.86%) were re-infected in this survey. After calibration of potential confounders, male gender, occupation as a farmer, smoking, and occasionally or frequently eating raw fish were independent risk factors for C. sinensis infection. The results of laboratory examinations in the C. sinensis /hepatitis B or C virus co-infection group were similar to those in the hepatitis B or C virus mono-infection groups. In conclusion, C. sinensis is highly endemic in villages along the Lalin River, and the primary route of infection is the consumption of raw freshwater fish. Co-infection with C. sinensis did't aggravate the clinical manifestations of viral hepatitis in this cross-sectional study.