Lack of implementation of Hepatitis B Virus (HBV) vaccination policy in household contacts of HBV carriers in Italy

BACKGROUND: In Italy, HBV vaccination is recommended and offered free of charge through the National Health Service to selected population groups – e.g., family members of an HBsAg carrier, healthcare workers, newborns and those who were 12-years old in 1991. However, a significant proportion of cases of acute hepatitis B still occur in Italy among persons who should have been vaccinated. We analysed HBV sero-prevalence data of two vaccination target populations (people born after 1980 and household contacts of an HBV carrier) living in a southern Italian area in order to evaluate HBV vaccine coverage and its possible determinants. METHODS: Between 2003 and 2006, we carried out a cross-sectional, population-based, sero-epidemiological survey on HBV infection on 4496 randomly selected individuals (aged 20 years or more) from the general population of the province of Naples. Sera were tested for antibodies to hepatitis B core antigen (anti-HBc) and to hepatitis B surface antigen (anti-HBsAg) by commercial immunoassays. Prevalence of past or current HBV infection and of HBV vaccination-induced immunity was calculated in two vaccination target populations. To analyze the association of epidemiological and socioeconomic characteristics with HBV vaccination of household contacts, we calculated crude and multiple logistic regression (MLR) odds ratio (OR). RESULTS: Prevalence of HBV vaccine-induced immunity (anti-HBs alone) was much lower among household contacts (25%) than among those who had been targeted for universal adolescent vaccination (81.6%). Male sex, older age, unemployment and lower education levels were associated to lower immunization rates. CONCLUSION: Understanding the different uptake of hepatitis B vaccination in these populations may provide useful information for optimizing vaccination campaigns in other contexts. Our data clearly demonstrated the need of improving the uptake of vaccination for household contacts of HBV carriers.