Hepatitis A shifting epidemiology in Poland and Eastern Europe.

The clinical morbidity of hepatitis A probably only represents 20% of cases of hepatitis A virus (HAV) infection. When it became possible to determine specific antibodies, a seroepidemiological survey of anti-HAV was undertaken in Poland, which showed that between 1979 and 1997 there was a shift in the peak age of infection from childhood to adulthood, concomitant with a substantial decline in the incidence of HAV infection. Data from the World Health Organization also indicate that there has also been a decline in the incidence of hepatitis A in Eastern European countries in general, over the 3 years from 1994 to 1996. The potential risk of epidemics still exists, however, when appropriate conditions are created. The available data show that fewer young people are becoming infected with HAV, and general preventive measures, including vaccination of children and high-risk groups (e.g. healthcare and childcare personnel and those living in 'closed communities') are needed to deal with HAV infections in Eastern Europe.