Seroepidemiology of infection with hepatitis A and B viruses in an isolated Pacific population.

To determine the prevalence of infection with hepatitis A virus and hepatitis B virus in an isolated population, samples of serum were collected from 574 healthy subjects living on the remote Pacific Island of Funafuti. Each specimen was tested for antibody to hepatitis A virus, hepatitis B surface antigen, and antibody to hepatitis B surface antigen by solid-phase radioimmunoassay. Overall, 79.8% of the population showed evidence of previous infection with hepatitis A virus, and 72.5% with hepatitis B virus; the high prevalence of antibody to both viruses in young adults suggested that the majority of infections were acquired in the first decade of life. Although it is known that hepatitis B virus maintains itself in isolated populations through a reservoir of chronic carriers, the reason for the persistently high rate of infection with hepatitis A virus is unknown.