Declining hepatitis A antibody seroprevalence in the Korean military personnel

We retrospectively analyzed serological test results for anti-hepatitis A virus immunoglobulin G (anti-HAV IgG) of sera collected from 779 military personnel during January 2001 to May 2008. The overall seroprevalence of anti-HAV IgG of the subjects was 17.5% (95% confidence interval [CI], 14.8-20.1%). When adjusted to the age-specific distribution of the army population, the age-adjusted seroprevalence was 14.6% (95% CI, 13.0-16.3%). All subjects who were 40 years and over had anti-HAV IgG. Meanwhile, the seroprevalence of anti-HAV IgG for those 24 years and younger was 4.7%. This low prevalence rate among young military personnel calls for stricter adherence to vaccination policies and stronger requirements for military HAV vaccination programs.