Change in Hepatitis A Seroprevalence among U.S. Children and Adolescents: Results from the National Health and Nutrition Examination Survey 2003-2006 and 2007-2010.

To examine changes in seroprevalence of antibodies to hepatitis A virus (HAV) during a period in which universal vaccine recommendations for all U.S. children were implemented, results from serologic testing from the National Health and Nutrition Examination Survey (NHANES) from 2003-2010 were analyzed among 7,989 participants age 6-19 years, born in the U.S. in two birth cohorts (1986-1996 and 1997-2004). Overall prevalence increased over time from 24.4% in 2003-2006 to the highest ever reported (37.6%) in 2007-2010. Specifically, increases reached statistical significance in the birth cohort born in the years after implementation of vaccine recommendations (1997-2004), among those of race/ethnicity other than white, non-Hispanic, and among states where recommendations were implemented later. The greatest increase over time was among the subgroup of persons in states with early implementation who were of race/ethnicity other than white, non-Hispanic. Geographic region and birth cohort based on vaccine recommendations as well as race/ethnicity were the main predictors of seropositivity in 2007-2010. The increase in Hepatitis A seroprevalence occurred during a time of decreasing incidence and increasing vaccination, however race/ethnic disparities persist.