SEROEPIDEMIOLOGIC SURVEY ON THE PREVALENC E OF ANTIHEPATITIS-A ANTIBODIES IN THE YOUNG-ADULT SPANISH POPULATION

BACKGROUND: The aim of the present was to study the rate of exposure t o the hepatitis A virus (HAV) in the young adult Spanish population. M ETHODS: A transversal observational study was performed to evaluate th e prevalence of anti-HAV antibodies (IgG) in a representative sample o f the Spanish population between the ages of 20-40 years. Information on demographic variables (age, place of residence, education, number o f children and number of brothers or sisters) and history of hepatitis was collected. A blood sample was also obtained from the umbilical co rd or heel of newborns. The level of total anti-KAV antibodies was mea sured by the ELISA method. RESULTS: A total of 1.204 pregnant women th e ages of 20-40 years with deliveries in 71 hospitals in 14 autonomic regions were included in the study. A total of 606 positive anti HAV w ere reported representing a prevalence of 50.4% (CI 95% = 48-52%). The prevalence was seen to significantly increase in relation to age, fro m 39% (group from 20-25 years) up to 60% (groups from 31-35 and 36-40 years of age). The factors of ''education'' and ''number of children'' , were not associated to greater risk of previous contact with HAV. A non significant increase in prevalence was observed in relation with ' 'number of brothers or sisters of the parturient''. 86.3% (CI 95% = 83 -93) of the positive anti-HAV subjects reported not having had clinica l history of hepatitis. CONCLUSIONS: Half of the young Spanish adult p opulation does not show antibodies against the hepatitis A virus, with an increase in morbidity by clinical hepatitis A being foreseen in th is age group.