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[Seroprevalence of antibodies against hepatitis A virus and hepatitis B virus in nonvaccinated adult population over 40 years of age].

STUDY OBJECTIVE
To determine prevalence rates of antibodies against hepatitis A virus (HAV) and hepatitis B virus (HBV) in the general adult male and female population over 40 years of age with no history of viral hepatitis A (VHA) and viral hepatitis B (VHB) who have never been vaccinated against hepatitis and to assess the cost-effectiveness of the pre-vaccination serological screening.


MATERIAL AND METHODS
In 2003-2004, a total of 972 persons of three age categories: 41-50 years, 51-60 years, 61 and more years, were screened. Persons with a history of VHA and/or VHB and those who had been vaccinated against hepatitis were not included in the study. The following four indicators were determined from a 5 ml specimen of whole venous blood by electrochemiluminiscence assay: total anti-HAV antibodies, total anti-HBc antibodies, anti-HBs antibodies and HBsAg, as the most suitable markers of experienced hepatitis or previous vaccination.


RESULTS
The prevalence rates of anti-HAV antibodies were lower in females compared to males for all of the three age categories. These antibodies were detected in 16.8%, 52.9% and 77.5% of 41-50-year-olds, 51-60-year-olds and > or = 61-year-olds, respectively. The total prevalence rate for the three age groups was 61.6%. The anti-HBc antibody seroprevalence rates were 1.9%, 5.3% and 6.1%, respectively.


CONCLUSION
The results show high prevalence of VHA in higher age groups. Such a high seroprevalence of antibodies in nonvaccinated persons with no history of viral hepatitis is suggestive of a very frequent incidence of asymptomatic infection. For this reason, the prevaccination screening of anti-HAV antibodies is cost-effective in the population over 50 years of age but is not justified in persons under 40 years of age. Prevaccination screening for anti-HBc antibodies appears not to be cost-effective regardless of age in view of their low prevalence in the Czech population.