title: The changing picture of hepatitis A in the United States.
abstract: OBJECTIVE
  Hepatitis A causes approximately half of the cases of viral hepatitis in the United States. Since 1999, routine hepatitis A immunization of children in areas of the United States with high rates of hepatitis A has been recommended.
  
  
  RESULTS
  There has been an increasing appreciation of the role of young children with asymptomatic or inapparent infection as the community reservoir of hepatitis A virus. Epidemiologic studies have demonstrated striking geographic variations in the incidence of hepatitis A in the United States. On the basis of this understanding, recommendations for control of hepatitis A were updated in 1999 to include routine vaccination of children living in states, counties, and communities with high rates of hepatitis A. Routine hepatitis A vaccination of children in areas with high rates of hepatitis A is a cost-effective strategy to reduce the incidence of hepatitis A.
  
  
  CONCLUSIONS
  Improved understanding of the epidemiology and transmission of hepatitis A combined with the availability of effective hepatitis A vaccines have dramatically reduced the burden of hepatitis A in the United States.
authors.affiliation: Department of Pediatrics and Center for Pediatric Research, Eastern Virginia Medical School and Children's Hospital of The King's Daughters, Norfolk, 23507, USA. Hal.Jenson@EVMS.edu
authors.forename: Hal B
authors.initials: HB
authors.lastname: Jenson
mesh_terms: D002648:Child; D005843:Geography; D006506:Hepatitis A / Q000453:epidemiology* / Q000517:prevention & control; D006801:Humans; D015994:Incidence; D014481:United States / Q000453:epidemiology; D014611:Vaccination