The impact of a vaccination campaign against hepatitis B on the further decrease of hepatitis B virus infection in a southern Italian town over 14 years

Abstract

Background: Hepatitis B virus infection has decreased in Italy. The aims of this study were to identify changes, if any, in the epidemiological pattern of HBV infection in a southern Italian town first surveyed in 1996 and to assess the effectiveness of vaccination campaign against hepatitis B.

Methods: In 2010, subjects were selected from the census by a systematic 1:4 random sampling procedure. Hepatitis B surface antigen (HBsAg) and antibodies to hepatitis B core antigen (anti-HBc) were detected by ELISA. Associations (odds ratios) linking exposure to hepatitis B virus infection to potential risk factors were estimated by univariate and multivariate analyses.

Results: Of the 1100 eligible subjects, 1020 (92.0%) agreed to participate. The prevalences of HBsAg (0.6%) and anti-HBc (15.2%) were significantly lower than in 1996 (0.8% and 21.5%) (p<0.01). No subject below 30 years of age (those that had been targeted for compulsory immunization) had been exposed to HBV infection. At multiple logistic regression analysis, age>45 years (OR=9.8; 95% CI=5.1-18.7) and past use of glass syringes (OR=1.9; 95% CI=1.2-3.1) independently predicted the likelihood of anti-HBc positivity.

Conclusions: These results, albeit obtained in a small town and thus not generalizable, confirm the continuous decreasing trend of HBV infection and demonstrate the effectiveness of the Italian hepatitis B vaccination program.