Risk factors for hepatitis B infection in rural Vietnam

Hepatitis B virus (HBV) infection is a significant public health problem in Vietnam, yet few data exist about the extent of infection.

To determine seroprevalence of HBV and the risk factors for HBV infection using a population-based epidemiological study in Vietnam.

A 400 person survey for seroprevalence of hepatitis B surface antigen (HBsAg) and HBV infection was carried out in five hamlets in the Linhson village of Thainguyen province from June to August 2006. HBV infection was defined as the presence of antibodies to hepatitis core antigen (HBcAb) and/or HBsAg, with or without HBsAg. Potential risk factors for HBV transmission were determined by a structured questionnaire.

Of the 383 respondents aged 18-70 years, 34 (8.8%) tested positive for HBsAg, of whom 21 (61.8%) were HBeAg-negative and hepatitis Be antibody (HBeAb) positive, and 22 (64.7%) had normal alanine aminotransferase (ALT) levels. The prevalence of HBV infection was 51.8% and increased significantly with age. Only 5.2% showed evidence of vaccination. On multivariate analysis, five predictors were found for HBV infection: male gender (OR 1.6; 95% CI 1.3-1.7), age greater than 40 (OR 2.1; 95% CI 1.4-3.3), Kinh ethnicity (OR 1.8; 95% CI 1.1-2.7), a low level of education (OR 1.7; 95% CI 1.0-2.7), and a history of surgery (OR 1.9; 95% CI 1.0-3.5).

The observed high prevalence of current and past infection with HBV in rural Vietnam highlights the need for close monitoring.