IFNA1 and chronic hepatitis C virus infection: Therefore, it can be seen that the association between IL28B rs8099917 and response to treatment is not definite in Asian patients with chronic hepatitis C. The prevalence rate of hepatitis C is 1-1.9% in China (16) where seldom studies investigated the influence of rs8099917 on the treatment outcome of hepatitis C patients with PEG-IFN/RBV.