New patterns emerge after a sustained increase in the incidence of hepatitis C virus infection from 2004 to 2017: a joinpoint regression analysis.

•This study describes the age- and sex-specific incidence trends of hepatitis C virus (HCV) infection in Hunan, China.•Joinpoint model illustrated the annual percentage change of HCV infection incidence trend.•Time trends of HCV infection incidence rates show significant changes over time.•The differences in incidence trends among demographic groups have obviously increased in the last 5 years.•People in high-age groups have still experienced increases in incidence rates in the last 5 years.