[Study on family aggregation and risk factors of hepatitis B virus transmission in Chaoyang district, Beijing].

Objective: To explore the family aggregation and risk factors of hepatitis B virus (HBV) transmission in Chaoyang district of Beijing.

Methods: A total of 5266 families were randomly selected for the multi-stage cluster sampling study in Chaoyang district of Beijing in 2010. The family members who aged between 1 and 70 years old and lived constantly in Beijing for over half a year, were recruited as subjects. There were 14 491 subjects in total, including temporary residents who did not have Beijing household account, except foreigners. 5 ml venous blood was drawn from every subject. A self-designed questionnaire was used to collect the basic information of the population and the risk factors of the hepatitis B transmission. Microparticle enzyme-linked immunoassay was applied to test five indicators of hepatitis B. Negative binomial distribution test was used among the HBsAg positive families to calculate the family aggregation rate of hepatitis B. Single factor analysis and multi-factor logistic regression model were used to analyze the risk factors of HBV transmission.

Results: In all, 308 out of 5266 families had HBsAg positive members, accounting for 5.85%.383 out of 14 410 subjects were HBsAg positive, rating at 2.66%. The HBsAg positive rate among subjects under 14 years old was the lowest, at 0.56% (9/1603); and the positive rate among subjects aging between 35 and 44 years old was the highest, at 4.27% (47/1029). Negative binomial distribution test showed that the family aggregation rate of HBV infection was 7.66% (χ² = 15.10, P < 0.05). The analysis of family aggregation of HBsAg positive showed that 17.39% (8/46) of the transmission was from father to child, 13.04% (6/46) was from mother to child, 30.44% (14/46) was between couples, and another 39.13% (18/46) was between siblings or other relatives. Both single factor analysis and multi-factor logistic regression analysis showed that hepatitis B positive family members (OR = 5.40, 95%CI: 5.24 - 5.55), hepatitis B positive friends and colleagues (OR = 1.55, 95%CI: 1.11 - 1.99) and blood donation and transfusion history (OR = 1.96, 95%CI: 1.76 - 2.15) were the risk factors of HBV infection.

Conclusion: HBV transmission showed family aggregation in Beijing, however, the risk factors needed further studies.