Objetivo: Determinar la prevalencia de marcadores serológicos para la infección por el virus de la hepatitis A y B en la población escolar del distrito de Huánuco e identificar los factores asociados a dichas infecciones. Materiales y métodos: en este estudio transversal analítico se seleccionó una muestra aleatoria y estratificada de 270 del total de escolares registrados en los diferentes centros educativos del distrito de Huánuco, Departamento de Huánuco-Perú, de abril a diciembre del 2000, en quienes se evaluó la presencia de HBsAg y anticuerpos anti-HAV, anticuerpos totales, anticuerpos IgM anti-HBcAg, anti-HDV y antígeno "e" en sangre (Estos últimos tres sólo a los HBsAg reactivos). La presencia de factores de riesgo para la infección por estos dos virus fue evaluada por una encuesta epidemiológica. Resultados: 257 (95,2%) escolares tuvieron Anticuerpos anti-HAV, 8 (3,0%) resultaron ser portadores de HBsAg, 62 (23,0%) tuvieron anticuerpos anti- HBcAg y ninguno de los 8 portadores de HBsAg tuvieron anticuerpos anti-HDV, anticuerpos IgM anti-HBcAg, ni antígeno "e" (HBeAg). La edad mayor a 11 años estuvo asociada a la presencia de anti-HAV (OR=14,3, p<0,001). El tener vivienda de adobe estuvo asociado a la reactividad al HBsAg (OR=5,1, p=0,045) y el tener relaciones sexuales estuvo asociado a la presencia de anticuerpos anti-HBcAg (OR=6,49, p=0,003). Conclusiones: el distrito de Huánuco tiene una alta endemicidad para HAV y endemicidad intermedia para el HBV. La edad mayor de 11 años estuvo asociada a una mayor infección por HAV y el tener vivienda precaria y relaciones sexuales a una mayor infección por HBV.

Objective: To determine the prevalence of serologic markers for viral hepatitis A and B infections in school boys and girls in Huánuco district, and to identify the risk factors associated to these infections. Materials and methods: In this analytic cross-sectional study; we selected a randomized and stratified sample comprising 270 subjects from the total school population in different institutions in Huánuco district, between April and December 2000. The presence of HBsAg and anti-HAV antibodies was assessed, as well as the presence of anti-HbcAg total antibodies, IgM anti-HBcAg antibodies, anti-HDV and "e" antigen in peripheral blood (the latter three tests were performed only in subjects positive for HBsAg). Risk factors for these two viruses were determined using an epidemiological survey. Results: 257 (95,2%) students had anti-HAV antibodies, 8 (3,0%) were found to be HBsAg carriers, 62 (23,0%) had anti-HBcAg antibodies and none of the eight HBsAg carriers had anti-HDV antibodies, IgM anti-HBcAg antibodies, not even "e" antigen (HBeAg). Being older than 11 years old was associated to the presence of anti-HAV (OR=14,3, p<0,001). Living in adobe houses was associated to HBsAg reactivity (OR=5,1, p=0,045) and having sexual activity was also associated to the presence of anti- HBcAg anti-bodies (OR=6,49, p=0,003). Conclusions: Huánuco district has high endemicity for HAV and intermediate endemicity for HBV. Being older than 11 years was associated to a higher prevalence of HAV infection; and living under precarious conditions and precocious sexual activity were associated with a higher prevalence of HBV infection.