Rates of reported hepatitis A virus infection, by age group, United States, 2004 to 2019

The rates of hepatitis A decreased in approximately all age groups during 2004 through 2009 and remained constant until outbreaks of hepatitis A began to be reported during 2016. The substantial increase in the rates of hepatitis A observed in recent years has been apparent in almost all age groups, except persons aged <20 years, which is consistent with the introduction of the hepatitis A vaccine in 1996 and the gradual expansion to universal childhood vaccination recommendations in 2006. During 2019, the highest rates were observed among persons aged 20 to 49 years, largely influenced by widespread hepatitis A outbreaks occurring among persons who use drugs and those experiencing homelessness.