High burden of hepatitis B infection in Northern Uganda: results of a population-based survey.

Background: Worldwide 2 billion people are exposed to hepatitis B infection, 350 million have chronic infection, 65 million in sub-Saharan Africa. Uganda is highly endemic with 10% national prevalence of hepatitis B infection, rates varying across the country from 4% in the southwest and 25% in the Northeast. Childhood vaccination was rolled out in 2002, the effect of which on the burden of hepatitis B has not been examined. We determined the prevalence and risk factors for hepatitis B infection in the Northern Uganda Municipality of Gulu.

Methods: We carried out a cross-sectional, population-based survey. The study population included those found at home at the time of recruitment. Data on demographics, wealth index, cultural and behavioral factors, vaccination and health education on hepatitis B were collected. Hepatitis B infection (Hepatitis B surface antigen positive) and lifetime exposure (anti-hepatitis B core antibody positive) were measured. Analysis was done in 2 age groups, 1-14 years, 14 years and more. Associations between predictors and HBV infection were assessed.

Results: Information on 790 respondents were analyzed. Overall, 139/790 (17.6%) had hepatitis B infection and 572/790 (72.4%) lifetime exposure. In the younger age group 16/73 (21.9%) had hepatitis B infection and 35/73 (48%) lifetime exposure. Increasing wealth was protective for infection (OR 0.46 per quartile, 95% CI=0.26-0.82, p=0.009), while older age was protective for lifetime exposure (OR 2.70 per age group, 95% CI 1.03-7.07, p=0.043). In the older age group, overall hepatitis B infection was seen in 123/717 (17.2%) and lifetime exposure in 537/717 (74.9%). The female sex (OR 0.63, 95% CI=0.42-0.98, p=0.032) and increasing age (OR 0.76 per age group, 95% CI=0.64-0.91, p=0.003) were factors associated with infection. For lifetime exposure, increasing number of lifetime sexual partners was a risk factor (OR 1.19 per partner category, 95% CI=1.04-1.38, p=0.012).

Conclusions: We found a high prevalence of hepatitis B infection and lifetime exposures to hepatitis B in this northern Uganda Municipality. Targeted vaccination of susceptible adults and improving existing childhood vaccinations and provision of treatment for those with infection will play roles in reducing the high prevalence rates seen in the population.