Abstract
BACKGROUND: The World Health Organisation (WHO) recommends the vaccination against Hepatitis B virus in all infants and children up to the age of 18 years. In addition, adults in high-risk groups should also be vaccinated. This study investigated the prevalence and factors associated with Hepatitis B Virus (HBV) infections among health professional students in the city of Mwanza, Tanzania in order to provide data that can assist in devising prevention and control strategies in this special group. METHODS: A cross-sectional study involving health professional students of the Catholic University of health and Allied Sciences was conducted between April and July 2016. Hepatitis B surface antigen was detected using rapid antigen test while the anti-hepatitis B surface antibodies(anti-HBs) were quantified using Enzygnost Anti-HBs II assay and anti-HBV core antibodies tested using enzyme immunoassay. RESULTS: A total of 1211 health professional students with median age of 22 interquartile range (IQR):21-24 years were enrolled. The slighlty majority (57.5%) of these students were males and 475(39.2%) were in clinical practices. Out of 1211 students, 37 (3.1%) were Hepatitis B surface antigen positive. Of 1174 students tested for anti-HBs, 258 (22%) had titres > 10 IU/L indicating HBV immunity. The median anti-HBs titres was 47.7 IU/L(IQR:16-3-113). A total of 230(89.2%) students among those who were positive for anti-HBs were also positive for HBV core antibodies indicating HBV natural infections. Male sex (adjusted odd ratio(AOR):1.77, p < 0.000), being married (AOR:1.82, p = 0.002) and being in clinical practices (AOR:1.39, p = 0.028) independenlty predicted anti-HBs positivity. CONCLUSION: A significant proportion of health professional students was naturally immune to Hepatitis B virus. There is a need to measure anti-HBs in order to reduce the cost of unnecessary vaccination especially in the countries with high endemicity of HBV.