[Serum antibodies against hepatitis A virus among subjects of middle and low socioeconomic levels in urban area of Santiago, Chile].

BACKGROUND

The epidemiology of hepatitis A virus (HAV) infection is closely associated to the level of hygiene and sanitation of the population. Newly industrialising areas experience a transition from high to intermediate endemicity, which is characterized by a shift in the exposure age to HAV, from early childhood to school ages or adolescence.

AIM

To measure the prevalence of HAV antibodies in subjects living in urban Santiago.

SUBJECTS AND METHODS

A HAV antibody survey in five medium and low socioeconomic level urban districts of northern Santiago, was conducted in 1996. Healthy subjects aged 1 to 39 years old were recruited from randomly selected households.

RESULTS

Five hundred three subjects were studied. Anti HAV antibodies were found in 13.2, 29.5, 59.6, 78.1, 95.6 and 98.2% of individuals aged 1 to 4, 5 to 9, 10 to 14, 15 to 19, 20 to 29 and 30 to 39 years old, respectively.

CONCLUSIONS

The profile of positive antibodies is compatible with an intermediate pattern of transmission of HAV. The current data supports the idea that infection is shifting towards older ages. A progressive increase in the number of susceptible school age children and teenagers is propitious for the occurrence of common source hepatitis A outbreaks.