Clonorchis sinensis infection and co-infection with the hepatitis B virus are important factors associated with cholangiocarcinoma and hepatocellular carcinoma.

To evaluate the contributions of Clonorchis sinensis and hepatitis B virus to the development of cholangiocarcinoma (ICC) and hepatocellular carcinoma (HCC), C. sinensis and hepatitis B virus infections in 20 clinical liver cancer cases from a C. sinensis- and hepatitis B virus-epidemic region were detected. Eight cases of ICC, 11 cases of HCC and one mixed ICC and HCC case were verified by CT, pathological section and (or) observations during surgery. The C. sinensis infection was detected by stool microscopy and ELISA, and the worms and eggs found during surgery and in pathological sections also allowed for diagnoses. Hepatitis B virus infections were detected by ELISA. In the 20 cases, 18 patients were diagnosed with C. sinensis infections. Eight of the 20 patients were infected with the hepatitis B virus, and seven were co-infected with C. sinensis. In the eight ICC patients, seven were diagnosed with C. sinensis infection, and two had mixed infections with the hepatitis B virus. In the 11 HCC patients, 10 were diagnosed with C. sinensis, four had mixed infections with the hepatitis B virus, and only one HCC patient presented a single infection by the hepatitis B virus. These clinical observations revealed that C. sinensis infection and C. sinensis co-infection with the hepatitis B virus are important factors in ICC and HCC.