Trends in Disease and Complications of Hepatitis A Virus Infection in the United States, 1999-2011: A New Concern for Adults

Background. In recent years, few US adults have had exposure and resultant immunity to hepatitis A virus (HAV). Further, persons with liver disease have an increased risk of adverse consequences if they are infected with HAV. Methods. This study used 1999-2011 National Notifiable Diseases Surveillance System and Multiple Cause of Death data to assess trends in the incidence of HAV infection, HAV-related hospitalization, and HAV-related mortality. Results. During 1999-2011, the incidence of HAV infection declined from 6.0 cases/100 000 to 0.4 cases/100 000. Similar declines were seen by sex and age, but persons aged >= 80 years had the highest incidence of HAV infection in 2011 (0.8 cases/100 000). HAV-related hospitalizations increased from 7.3% in 1999 to 24.5% in 2011. The mean age of hospitalized cases increased from 36.0 years in 1999 to 45.1 years in 2011. While HAV-related mortality declined, the mean age at death among decedents with HAV infection increased from 48.0 years in 1999 to 76.2 years in 2011. The median age range of decedents who had HAV infection and a liver-related condition was 51.0 to 68.0 years. Conclusions. Although vaccine-preventable, HAV-related hospitalizations increased greatly, mostly among adults, and liver-related conditions were frequently reported among HAV-infected individuals who died. Public health efforts should focus on the need to assess protection from hepatitis A among adults, including those with liver disease.