Occult Hepatitis B Virus Infections in HIV-1 subtype C Infected Individuals in Botswana: Incidence, Kinetics and Mechanisms

Hepatitis B virus (HBV) is a significant cause of morbidity and mortality in HIV-infected individuals. There are limited data on the impact of occult hepatitis B infection (OBI, defined as detectable HBV deoxyribonucleic acid in the absence of detectable hepatitis B surface antigen (HBsAg), on HIV progression. We will determine the prevalence, kinetics and mechanisms of OBI in untreated HIV-infected individuals from Botswana. HBV screening will be conducted at 6-month intervals. HBV characteristics from HBsAg positive individuals and OBI positive individuals will be compared to get characteristics unique to the OBI group. The impact of OBI-associated mutations on the virus will first be determined using predictive algorithms. Mutations deemed to have an impact on virus replication in the present study and from a previous study from our group will be evaluated in the laboratory. Data from this study will guide future diagnostic kits and preventative strategies.