[Study on the prevalence rate and immunity of hepatitis B virus infection among urban adults aged over 20 years in Wuxi, Jiangsu province].

Objective To study the relationship on the prevalence rate of hepatitis B virus (HBV) infection and hepatitis B vaccination in urban citizens aged over 20 years old which would led to the development of strategies on HBV control. Methods A total of 3744 subjects from general population were randomly selected in this study. Both ELISA and radio immunoassay were used to test five items of HBV infection, including HBsAg, anti-HBs, HBeAg, anti-HBe and anti-HBc. Results The overall standardized infection rate of HBV was 51.7%, and HBsAg, anti-HBs, HBeAg, anti-HBe and anti-HBc were 4.5%,48.5 %, 0.3 %, 3.5 % and 51.4 %, respectively. The two lowest HBsAg positive rates were found in the groups under 30 years old (2.9%) and students (2.6%). Anti-HBc rate among men was significantly higher than seen in women (P for trend= 256.2,P<0.001 ). The standardized rates of HB vaccination in this population was 17.6% and decreasing rapidly with age (P<0.05). People who had been vaccinated had both lower rates of HBsAg and HBV infection but higher rate of anti-HBs than those who had not (P<0.05). Conclusion liB vaccination in adults showed a reducing rate of HBV infection in the general population. Together with the enhancement of expanded program on immunization to wards HB vaccination in neonates, much attention should be paid to HB vaccination in adults. Key words: Hepatitis B virus;  Natural population;  Immunity