Background: In recent years there has been a substantial reduction in hepatitis B incidence as a result of routine vaccination of preadolescents and the selective vaccination of high risk groups and newborns of HBsAg+ mothers.
Objectives: To determine the prevalence of hepatitis B virus infection markers and of serologic markers of hepatitis B vaccination in a representative sample of pregnant women in Catalonia.
Study design: A representative sample was obtained by random cluster sampling (hospitals with maternity units) stratified by provinces. Anti-HBc, anti-HBs and HBsAg were determined using an ELISA test (Behring, Marburg, Germany). The crude and adjusted odds ratios for the sociodemographic variables analyzed were also calculated.
Results: The global prevalence of carriers of HBsAg+ was 0.1% (95% CI 0.0-0.3), that of hepatitis B infection (anti-HBc+) was 5% (95% CI 3.9-6.1) and that of serologic markers of vaccination (anti-HBs+ and anti-HBc-) was 16.4% (95% CI 14.5-18.2) The prevalence of infection increased with age from 3.0% (15-19 years age group) to 14.8% (40-44 years age group). The prevalence of anti-HBc+ was higher in women born in Asia (27.6%) and Africa (18.8%) than in those born in Spain (3.7%), Europe (3.3%) and America (4.6%), with the differences being statistically significant.
Conclusions: The results of this study confirm the change in the pattern of endemicity of hepatitis B infection in pregnant women in Catalonia after the introduction of vaccination programmes. They also confirm the increasingly important role played by immigration in the epidemiology of hepatitis B.