Among HIV-infected individuals in Africa, liver disease is a neglected area of investigation but is anticipated to become increasingly common as patients live longer due to antiretroviral therapy. In a currently approved and active research study taking place in Lusaka Urban district - HIV/HBV co-infection in IeDEA-SA (NCT02060162, clinicaltrials.gov) - 800 consecutive HIV-infected adults were screened for possible causes of liver disease and 12% were diagnosed with chronic hepatitis B virus (HBV) co-infection. HBV co-infected patients were more likely to have evidence of liver disease; however, ascertainment of critical long-term outcomes of HIV-HBV patients was not part of the study. Building on these preliminary results and addressing the need to study HIV-HBV during a longer duration of follow-up, the current protocol will focus exclusively on Zambian HIV-HBV patients. In the proposed study, the investigators will determine the risk factors for liver disease among Zambian HIV-HBV co-infected patients, and assess the long-term effectiveness of Ministry of Health (MOH)-recommended antiretroviral drugs in the prevention and/or reduction of HIV-HBV liver disease. This study will provide useful clinical and epidemiologic information to health policymakers in Zambia and throughout the region and may lead to improvements in the care of HIV-HBV patients. Further, it will strengthen collaboration between Zambian institutions and strengthen local capacity in HBV diagnosis and management.