Changing epidemiology of hepatitis A virus (HAV) infection: a comparative seroepidemiological study (1979 vs 1989) in north-east Italy.

A comparative seroepidemiological study (1979 vs 1989) on HAV infection, was carried out in children and adolescents from North-East Italy. Anti-HAV was tested in 850 subjects 6 to 8 years of age and the results were compared to those observed in 1979, in 462 subjects of the same age range and from the same geographical area. Overall anti-HAV prevalence was 1.9% (ranging from 0.5 to 5.2) in 1989 vs 32.5% (ranging from 7.8 to 70.7) in 1979. This dramatic decline of HAV infection in children and adolescents reflects the improved sanitation standard of our country but, on the other hand, indicates that the number of non-immune adults is increasing, with a higher risk of symptomatic infection in the near future.