Seroprevalence of viral hepatitis A in the Czech Republic.

Over recent decades, the epidemiology of hepatitis A has changed in most European countries: the age of infection has been shifting towards older age groups. In view of this evolution and the central location of the Czech Republic in Europe, we wanted to assess current anti-hepatitis A seroprevalence. We determined the anti-hepatitis A seroprevalence among three different groups: military personnel between 1991-1995, prior to their deployment as UN troops, civilians participating in a national serological survey in 1996 and volunteers for vaccine clinical trials in 1996. The anti-HAV prevalence <20 years of age was about 4%; in the age cohort 40-49 it ranged between 47 and 51%. Only over the age of 60 years was the seroprevalence rate >85%. The risk of acquiring HAV is low for younger age groups. We could demonstrate some regional differences with higher rates in some age strata for the North Bohemian region and the lowest rates in East Bohemia and Prague. Compared to archived sera from a previous serological survey in 1984 we demonstrate a shift towards low endemicity. For the first time it is shown that an Eastern European country, i.e. the Czech Republic, is a country with a low endemicity for HAV. Substantial parts of the population are or will be at an increased risk of HAV infection and active immunisation against HAV should be considered.