The changing pattern of hepatitis B virus infection over the past three decades in Italy.

By the end of 1970s, Italy was a country at medium endemic level of hepatitis B virus infection, with wide geographical differences; intrafamily transmission was the major mode by which infection spread; hepatitis B e antigen positivity and hepatitis Delta positivity were frequently detected in hepatitis B surface antigen chronic carriers; a high proportion of subjects with chronic liver disease resulted as hepatitis B surface antigen positive. Three decades apart, the picture was completely changed, as documented by several surveys. Nowadays, Italy is a country at very low endemic level of hepatitis B, without geographical differences; the infection is mostly sexually transmitted; hepatitis B e antigen positivity and hepatitis Delta positivity are rarely detected in hepatitis B surfaces antigen chronic carriers; a low proportion of subjects with chronic liver disease result hepatitis B surface antigen positive. These important changes may be due to both non-specific (i.e. improvement in socio-demographic features) and specific (i.e. a comprehensive vaccination program against hepatitis B) preventive measures.