[Seroepidemiologic survey of hepatitis A antibodies in the young adult Spanish population. Spanish Study Group on hepatitis A (1)].

BACKGROUND

The aim of the present was to study the rate of exposure to the hepatitis A virus (HAV) in the young adult Spanish population.

METHODS

A transversal observational study was performed to evaluate the prevalence of anti-HAV antibodies (IgG) in a representative sample of the Spanish population between the ages of 20-40 years. Information on demographic variables (age, place of residence, education, number of children and number of brothers or sisters) and history of hepatitis was collected. A blood sample was also obtained from the umbilical cord or heel of newborns. The level of total anti-HAV antibodies was measured by the ELISA method.

RESULTS

A total of 1,204 pregnant women the 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 were reported representing a prevalence of 50.4% (CI 95% = 48-52%). The prevalence was seen to significantly increase in relation to age, from 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 clinical history of hepatitis.

CONCLUSIONS

Half of the young Spanish adult population does not show antibodies against the hepatitis A virus, with an increase in morbidity by clinical hepatitis A being foreseen in this age group.