[Prevalence of antibodies against hepatitis A in school children].

Background: As sanitary conditions of a population improve, hepatitis A virus infection occurs at higher ages, thus decreasing the prevalence of antibodies against the virus. In the eighties, the prevalence of antibodies among children was 97% and depended on the socioeconomic level.
Aim: To assess the prevalence of antibodies against hepatitis A virus in school age children living in Valdivia.
Subjects and Methods: Two thousand three hundred thirty three school age children were studied. Total antibodies against hepatitis A virus were detected using an ELISA kit from Abbott. Children were stratified in age groups and school were classified as private, subsidized, municipal or foster homes.
Results: Antibodies were positive in 65% of children (59% in children aged 6 to 8 years old, 66% in children aged 9 to 11 years and 69% in children aged 12 to 15 years. In private schools, the prevalence was 26%, in subsidized schools the figure was 54%, in municipal schools 73% and in foster homes 91%.
Conclusions: The general prevalence of antibodies against hepatitis A virus is higher in low socioeconomic level children. There is a global decrease in the prevalence of these antibodies in the last years.