HIV/hepatitis B virus co-infection: current challenges and new strategies.

Chronic hepatitis B virus (HBV) infection, which affects 7%-10% of HIV-infected patients, is associated with an increased frequency of AIDS-related and non-AIDS-related clinical endpoints, such as end-stage liver diseases including cirrhosis and hepatocellular carcinoma. Broad access to a very efficient antiviral therapy containing nucleos(t)ide analogues with dual activity against HBV and HIV reverse transcriptases has initiated a transition in the paradigm of HBV control in the context of HIV-induced immunosuppression. The control of viral replication is not currently such a problem, but preventing the emergence of HBV polymerase and surface gene mutants after prolonged exposure to nucleos(t)ides and their consequences in terms of HBV vaccine escape are the next long-term challenges. Another challenge is the prevention of end-stage liver disease in an ageing population, in whom non-invasive markers of liver fibrosis, although used more frequently as a substitute for liver biopsy, are not the panacea. Finally, access to prevention, diagnosis, care and treatment of HBV infection remains a major issue in developing countries, including most regions of Africa and Asia, where HBV is endemic and the epidemic of HIV infection is still thriving.