Antiretroviral therapy (ART) has dramatically reduced AIDS-related mortality and, as a consequence, led to an increase in life expectancy of HIV-infected individuals. Comorbid conditions, including liver disease due to hepatitis B Virus (HBV) and hepatitis C virus (HCV) infections, have thus become major causes of death in HIV-infected individuals in industrialized countries, and the same is expected to become true for resource-limited settings (RLS). Worldwide, 90% of HIV-infected patients have evidence of previous HBV infection, and chronic HBV infection is the single most important risk factor of end-stage liver disease and hepatocellular carcinoma. Due to shared routes of transmission, HIV and HBV are often concomitant infections; between 5% and 15% of HIV-infected persons also have a chronic HBV infection. HIV infection has a profound impact on the natural history of HBV infection, including the acceleration of the progression to end-stage liver disease. HCV infection seems to be less prevalent in sub-Saharan Africa (SSA) compared to most other regions in the world.
HIV/HBV-coinfected patients who receive an ART regimen that includes lamivudine or emtricitabine as the only drug with activity against HBV rapidly develop drug resistance. Treatment outcomes are improved by the use of tenofovir disoproxil fumarate (TDF), which is now part of first-line ART in RLS. Besides having optimal virological efficacy against HBV infection, TDF also seems to lead to the reversal of liver fibrosis. However, its impact on long-term HBV virological outcomes and liver-related disease in SSA has not been studied in detail. As many of these patients treated with TDF need two to three years of therapy before achieving HBV virological suppression, long-term data on HBV virological response to TDF in SSA are urgently needed.
What we’re doing
In IeDEA-SA, very few cohorts were routinely collecting data on viral hepatitis B infection, and most clinics did not test for HBV and HCV infections. Thus, we had to design a dedicated research project to study the epidemiological, clinical and virological determinants of HBV infection in specific HIV cohorts. We established cohorts in which HBV and HCV infections were described and liver fibrosis was assessed, and we implemented chart reviews and online surveys to explore programmatic aspects related to the management of viral hepatitis infections. HIV/HBV-coinfected individuals in Zambia and Mozambique are followed over a period of at least five years, as data on long-term clinical and virological outcomes are scarce in southern Africa.
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