Hepatitis B Infection and Immunity among Pregnant Women Attending Antenatal Clinics in Health Centers of Mbarara Municipality, Southwestern Uganda

Abstract

Introduction: Viral hepatitis B (HBV) in pregnancy is a risk for childhood transmission where the majority become chronically infected. In Uganda, HBV is not tested for during antenatal, therefore the number of infected, infectious, immune and none-immune pregnant women is unknown curtailing efforts to prevent mother to child transmission. Methods: We conducted a descriptive cross-sectional study involving 254 pregnant women from four health centers in Mbarara Municipality. HBV status was assessed using an immunochromatographic (COMBO) kit, the type of infection; based on demonstration of anti hepB core IgM (acute infection) and total core IgG antibodies (chronic infection) and infectiousness; based on the presence of HBeAg and/or a quantitative HBV viral load ≥ 20,000 IU/mL. Immunity was determined using the COMBO kit and HBsAb quantification ELISA. One was deemed immune to HBV if HBsAb titers were ≥10 mIU/mL. Results: The prevalence of HBV infection was 1.2%; 33% and 67% with acute and chronic HBV respectively. 33% were infectious based on a high viral load, none had detectable HBeAg. 14% were immune; amongst whom 72% had natural exposure and 18% after vaccination. There was insufficient immunity in 11% with a majority (75%) having acquired immunity following vaccination. Conclusion: The prevalence of HBV is low and most of those are chronically infected. HBeAg and Hepatitis B viral load should be performed when evaluating infectiousness. Further, there is a high transmission of HBV among adults and a low uptake of the HBV vaccine in Mbarara Municipality.