Objective: Hepatitis B virus (HBV) infection remains a significant public health problem. The purpose of this study was to investigate the seroepidemiology of HBV in people living in the insular regions, and to provide the most recent baseline data for planning and monitoring of health.
Methods: A cross-sectional, community-based survey was conducted without age restriction, on two isolated islands, Zhoushan and Yuhuan, China. The study sample was selected by random multistage cluster sampling. Serological samples and demographic information were collected from 15878 participants.
Results: The prevalences of anti-HBV core antibody (anti-HBc), hepatitis B virus surface antigen (HBsAg), and anti-HBV surface antibody (anti-HBs) were 33.1, 10.4, and 56.1%, respectively. We found statistically significant differences of HBV markers in men versus women (P<0.01). The prevalence of HBV infection increased with age. There were significant differences in the rates of HBsAg and anti-HBc positivity between the two islands (P<0.01). Alanine aminotransferase (ALT) levels were elevated (>38 IU/L) in 15.6% and 7.2% of the HBsAg-positive and negative groups, respectively. Elevated ALT levels were significantly higher in males (12.0%) compared with females (5.8%) (P<0.01). The α-fetoprotein (AFP) positivity rate was 0.6% in HBsAg-positive participants over the age of 30.
Conclusion: Due to the geographic location, we found that the HBV prevalence and potential for the development of hepatocellular carcinoma remained high in insular regions of southeast China, and are far above the national figures. Although a vaccination program has been in effect over the last 20 years, several additional measures should be adopted by the government to limit the spread of hepatitis B. These include the management of high risk persons and the floating population living on the islands, expansion of the immune population, and increased health education for fisherman.