A Surveillance Program for the Detection of Hepatitis B Virus (HBV) Resistance to Tenofovir in HIV-HBV co-Infected Patients

Human immunodeficiency virus/Hepatitis B virus (HIV/HBV) co-infections are frequently observed due to shared routes of transmission, with reported figures indicating 6-9% of HIV-infected individuals in developed countries are chronically infected with HBV. HIV infection impacts on the natural progression of HBV infection, increasing levels of HBV replication and the risk of liver-associated mortality. Liver diseases associated with HBV are affected by the antiviral drugs used for HIV infection (toxic side effects), the current immune function in the patient, by improvements in the immune system brought about by control of the HIV infection, and by the development of resistance to the antiviral agents used for both the hepatitis B and the HIV infection. Tenofovir (TDF) is a newer antiviral drug that is frequently used for HIV infection and is also highly active against hepatitis B; however it is still unknown whether resistance to TDF will eventually develop and how this will affect the long-term outcomes