Prevalence of hepatitis B virus infection in a population exposed to biological risk.

The prevalence of hepatitis B virus infection was investigated in 1,221 subjects (809 exposed to different extent of biological risk and 412 supposed not exposed personnel) employed in Padua University. The population was subdivided in four group according to no, low and occasional, intermediate, even though continuous, and high exposure to biological risk. Past history of hepatitis B virus infection was detected in 10.0% of subjects (8.8% had positive hepatitis B antibodies, 1.1% positive hepatitis B surface antigens and 0.2% positive hepatitis B enveloped antigen). Seroprevalence of positive hepatitis B antibodies increased with age (p < 0.001) but was not related with sex. Significant higher prevalence of hepatitis B virus infection was not found among the groups, but excluding vaccinated subjects (333, 27.3%), the prevalence was significantly higher in intermediate (p < 0.025) and high (p < 0.001) risk group when compared with the other two groups, other than in high compared with intermediate risk group (p < 0.05). The results show low prevalence (10.0%) of hepatitis B virus infection in the examined population, but increasing according to the risk extent.