[Frequency of hepatitis a in children and adolescents from five cities of Peru].

In order to determine the frequency of hepatitis A in children and adolescents in the cities of Lima, Arequipa, Piura, Cajamarca and Iquitos, a descriptive cross-sectional study which measured serum anti-hepatitis A antibodies from 1,721 children and adolescents aged 1-15 years was performed. The overall frequency of positive serology was 50.5% (95% CI: 48.