The impact of the hepatitis B mass immunisation campaign on the incidence and risk factors of acute hepatitis B in Italy

Background/Aims: This study aimed to evaluate the impact of the campaign fo r hepatitis B mass immunisation of children and teenagers, introduced in 19 91, on the incidence of and risk factors for hepatitis B in Italy, Methods: Hepatitis B cases reported to the surveillance system for type-spe cific acute viral hepatitis (SEIEVA) during the period 1987-1997 were used to estimate incidence. To assess the association between potential risk fac tors and hepatitis B cases, hepatitis A cases generated by the same surveil lance system were used as controls. Results: During the period 1987-1997, 8275 acute hepatitis B cases were rep orted to SEIEVA, Hepatitis B incidence declined from 10.4/100 000 in 1987 t o 2.9/100 000 in 1997, The fall was more evident before than after the intr oduction of compulsory vaccination against hepatitis B, The results of mult ivariate analysis showed that during the years 1995-1997, blood transfusion , intravenous drug use, surgical intervention, dental therapy, other parent eral exposures, multiple sexual partners, and being in the household of a c hronic HBsAg carrier were all exposures independently associated with hepat itis B. Conclusions: The strong association linking acute hepatitis B with iatrogen ic exposures, which are more common in adults, suggests that the present im munisation strategy should be combined with the implementation of non-immun ologic preventive measures.