Abstract
Hepatitis B virus (HBV)/hepatitis C virus (HCV) co-infection shares the same transmission routes, and thereby it is not rare in regions where the prevalence of HBV and HCV is high. However, the co-infection rates of HBV/HCV reported in different regions of the world are relatively dissimilar, and the co-infection rates of HBV/HCV in the population are unidentified due to the presence of silent HBV infection. Thus, the phenomenon of underestimation exists. HCV may have an inhibitory effect on HBV replication when HBV/HCV is co-infected, and the effect of HBV on HCV replication remains to be certain by more studies. Furthermore, the mechanism of interaction may include the direct effect of viral proteins and the indirect effect of immune mediated host response. HBV/HCV co-infection can cause more serious chronic liver diseases and cirrhosis, and can increase the risk of liver cancer. The efficacy of peginterferon plus ribavirin in patients with HBV/HCV co-infection is same as HCV monotherapy. There are few studies on the efficacy of direct-acting antiviral drugs. Patients with HBV/HCV co-infection have the risk of HBV reactivation regardless of anti-HCV treatment with peginterferon plus ribavirin or direct-acting antiviral drugs, but the probability of HBV reactivation and how to assess and prevent it needs more studies to interpret.