[Seroepidemiological study and program of vaccination against hepatitis B in school children in Extremadura].

Abstract

Background: The control of Hepatitis B as a community health problem which implies the reduction of the number of cases and carriers cannot be achieved merely through selective vaccination of high risk groups and immunization of newborns whose mothers are carriers. The decision to introduce universal vaccination on a constant basis should be based on the epidemiological characteristics of the infection in the community, among other reasons.

Methods: Along these lines, a study of seroprevalence of the infection was carried through a random sampling of ages groups taken from a population with no history of hepatitis and low risk groups, using a survey of 855 people and a retrospective study of seroprevalence in different high risk groups with a survey of 2,183 people.

Results: The prevalence of infection estimated at intervals in the general population not included in high risk groups is 8.05-12.07, and that of carriers of HBs Ag 0.07-1.09. The risk of infection increases significantly after 14 years of age (p < 0.001) with an OR of 25.22. Sexual transmission as a means of spreading the virus among the general public is demonstrated by the data obtained from sexual promiscuous People and prostitution: 58.53% and 44.21% respectively.

Conclusions: We consider it necessary to employ universal vaccination of adolescents within the children's immunization programmes, at a recommended age of 13 before finishing primary school and abandoning school, while still keeping the prophylactic measures and immunization of high risk groups. This will also allow us to simultaneously prevent infection by Hepatitis Delta in the Autonomous Community both as a co-infection by HBV and an overinfection. In this programme we advocate the elimination of serological studies on Hepatitis B (due to cost-efficiency studies) and are in favour of periodic future research on seroPrevalence.