Prevalence of hepatitis B virus (HBV) infection in Singapore men with sexually transmitted diseases and HIV infection: role of sexual transmission in a city state with intermediate HBV endemicity

摘要

Study objectives - To describe the prevalence of hepatitis B virus (HBV) infection in patients with sexually transmitted diseases (STD) and human immunodeficiency virus (HIV) infection, and to determine the role of sexual transmission of HBV infection in Singapore. Design — A cross sectional study of all consecutive men presenting with a new episode of STD at a government outpatient clinic and all men with HIV infection on routine follow up at a government hospital. The prevalence of various HBV markers was compared with that of healthy males aged 15 years and above (controls). Setting - Singapore, a city state of intermediate HBV endemicity. Subjects - These comprised 497 STD patients, 47 HIV infected patients, and 418 controls. Main results — The overall seroprevalences of HBV infection in STD patients, HIV infected patients, and control subjects were 41.2%, 61.7%, and 33.3%, respectively (p<0.001). The seroprevalences of hepatitis B surface antigen (6.2%, 8.5%, and 4.5%, respectively) were comparable in the three groups. Using stepwise logistic regression analysis, the adjusted seroprevalences of HBV infection in STD and HIV infected patients were respectively 2.4 times (95% confidence interval (CI), 1.7, 3.3) and 3.3 times (95% CI 1.7, 6.3) higher than in controls. HBV infection rates were higher among Chinese (odds ratio (OR), 1.9; 95% CI 1.6, 3.4) than non-Chinese, and among those aged 25-34 years (OR 2.4; 95% CI 1.6, 3.4), 35-44 years (OR 3.9; 95% CI 2.5, 5.9), and 45 + years (OR 6.2; 95% CI 3.8, 10.2) than in those aged 15-24 years. Sex related factors significantly associated with higher infection rates, independent of age and ethnic group, were reactive VDRL test (OR 2.4; 95% CI 1.2, 4.7), participation in anal intercourse (OR 2.3; 95% CI 1.2, 4.3), and having 10 or more lifetime sexual partners (OR 1.5; 95% CI, 1.0, 2.1). Conclusion - The importance of sexual transmission of HBV in an area of intermediate HBV endemicity was con- firmed. Patients attending STD clinics should be routinely screened for HBV markers and those found to be sero-negative should be strongly advised to be immunised against this virus.