Incidence of hepatitis B virus infection among an Italian military population: evidence of low infection spread.

In 1990, a prospective serological survey to estimate the rate of clinical and inapparent infection with hepatitis B virus was performed in a cohort of 1324 soldiers, 18-24 years old, during an eight-month period in Italy. At the time of enrollment the prevalence of hepatitis B markers was 4.6% (0.7% subjects positive for hepatitis B surface antigen [HBsAg], 3.0% positive for antibody to hepatitis B surface antigen [anti-HBs], and 0.9% positive for antibody to hepatitis B core antigen [anti-HBc] alone. Among the 1263 susceptible subjects who were followed-up, only 2 (0.24/100 person-years of exposure) had seroconversion for HBV markers, none of which was associated with clinical illness. Among the 9 subjects HBsAg-positive at the time of enrollment, 1 (11.2%) had lost HBsAg at the end of follow-up. These data show a low spread of HBV infection among Italian young generations.