Risk factors of hepatitis B virus infection between vaccinated and unvaccinated groups among spouses in 2006 and 2014: a cross-sectional study in Beijing

Objectives: To assess the prevalence of hepatitis B virus (HBV) infection among married individuals and to analyze the associated risk factors of HBV infection in vaccinated and unvaccinated groups in 2006 and 2014. Methods: Information of married individuals aged over 16 y with a clear HBV vaccination status was extracted from the database constructed by the Beijing Center for Disease Prevention and Control from population-based investigation. A structured questionnaire was employed to collect demographic information, vaccinated history, and other related influence information of HBV of participants. Pearson chi-square test, Fisher's test, and logistic regression were used to explore the risk factors of HBV infection. Results: A total of 2874 individuals in 2006 and 1622 individuals in 2014 were enrolled in our study. The mean age of individuals was 49.30 and 46.68 y in 2006 and 2014, respectively. The overall positive rates of HBsAg, anti-HBc, and single anti-HBs were 4.80%, 43.01%, and 5.78% in 2006, which were 4.69%, 38.22%, and 14.18% in 2014, respectively. For vaccinated individuals, age was significantly correlated with anti-HBc in 2014 (40 < age <= 50 versus age <= 30, relative risk (RR) = 3.03, 95% confidence interval (95%CI) = 1.04-8.84). Gender [male versus female, RR = 0.60, 95%CI = 0.36-1.00 (2006); RR = 0.71, 95%CI = 0.52-0.97 (2014)] and age (in 2006) were found to be significantly associated with single anti-HBs. For unvaccinated individuals, HBsAg positivity was statistically significant correlated with gender [RR = 1.47, 95%CI = 1.04-2.06, in 2006], residence (urban versus rural, RR = 0.40, 95%CI = 0.24-0.67, in 2006; RR = 0.58, 95%CI = 0.34-0.99, in 2014), sharing syringes [RR = 3.75, 95%CI = 1.33-10.63 (in 2006); RR = 2.07, 95%CI = 1.26-3.41 (in 2014)], infected wives (RR = 1.97, 95%CI = 1.28-3.05, in 2006), and infected husbands (RR = 2.19, 95%CI = 1.25-3.82, in 2006). Anti-HBc positivity was significantly associated with gender [RR = 1.19, 95%CI = 1.10-1.30 (in 2006); RR = 1.24, 95%CI = 1.09-1.40 (in 2014)], age (in 2006 and 2014), endoscopic medicine treatment [RR = 1.16, 95%CI = 1.03-1.32 (in 2006), RR = 1.21, 95%CI = 1.01-1.45 (in 2014)], sharing syringes (RR = 1.43, 95%CI = 1.25-1.64, in 2014), body piercing (RR = 0.84, 95%CI = 0.75-0.93, in 2006), infected wives (RR = 1.32, 95%CI = 1.18-1.47, in 2006), and infected husbands (RR = 1.39, 95%CI = 1.22-1.59, in 2006). Anti-HBs positivity was associated with age (in 2006 and 2014). Conclusions: Prevalence of HBV infection was lower in 2014 than in 2006 according to HBsAg and anti-HBc positivity. Unvaccinated individuals faced much more risk of HBV infection than those of vaccinated.