Changing epidemiology of hepatitis B in Italy: public health implications.

In Italy, a dramatic decline of hepatitis B infection occurred in recent years as a result of nonmedical and medical factors. The national type-specific surveillance system shows that the age of maximum incidence changed from early childhood, when the risk of becoming a chronic carrier after infection is very high, to late adolescence. Data of several seroepidemiologic studies are consistent with this picture, but could not be compared with previous data on similar age groups. In 1981, a seroepidemiologic study on a national sample of 5,005 recruits showed a high prevalence of serologic markers of hepatitis B infection among young adults in Italy. In 1990, the authors replicated that original study on a national sample of 4,993 recruits. The adjusted prevalence of hepatitis B core antibodies among Italian male recruits dropped from 16.8% to 5.8% in 9 years. The authors anticipate a substantial reduction in the rate of production of chronic carriers and the rates of liver cirrhosis and primary liver carcinoma in Italy in the next decades. Vaccination campaigns, especially if combined with nonimmunologic preventive measures, will further reduce the rate of hepatitis B infection in Italy.