Occult hepatitis B virus infection and reactivation in Africans in the context of the human immunodeficiency virus pandemic

• Applicant: Professor Dr. Dieter Glebe
• Co-Applicants: Professorin Dr. Anna Kramvis; Professor Dr. Hatim M.Y. Mudawi
• Subject Area: Virology
• Term: from 2010 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 164446449

Infection with hepatitis B virus (HBV) is one of the most important viral infections in Africa, in terms of morbidity and mortality, causing massive public health problems. Infection with HBV can result in acute and chronic infections, but only 10% of HBV infections in adult immune competent persons lead to overt chronic infections while 90% showing serological signs of resolution. However, even in resolved cases, HBV can persist silently in the liver in form of occult hepatitis B, and can be reactivated following severe immunosuppression of the patient. In Europe, this is mostly the result of immunosuppressive therapy, but is also observed during acquired immunodeficiency syndrome (AIDS) in HIV-infected patients. In Africa, severe immunosuppression is mostly due to the appearance of AIDS, since most of the HIV-infected persons are not well treated with suitable antivirals. In Europe, the appearance of occult hepatitis B and reactivation in HBV/HIV co-infections is rare, due to the limited number of cases and highly efficient antiviral HIV therapy (HAART) available. However, in Africa, HBV/HIV coinfections are hundred times more frequent due to the HIV pandemic, leading to much higher cases of occult hepatitis B and an increased risk of HBV reactivation in HBV/HIV infected patients due to immunodeficiency by HIV. This is often associated with selection of HBV mutants, occasionally leading to fatal hepatitis B disease. The increased transmission of selected HBV mutants from reactivation endangers HBV diagnosis, antiviral therapy and the whole HBV vaccine program in Africa because of the appearance of escape-mutations. Our major objectives are to elucidate the nature of reactivated HBV in HBV/HIV co-infected patients, showing previous signs of resolved or occult HBV infection. The characterisation of emerging HBV mutants in those patients will help to understand the epidemiological and pathogenic role of HBV escape mutants in a population with very high HBV and HIV prevalence. The anticipated improvement of laboratory infrastructure and training of scientific personnel as a result of the close cooperation with European partners, will facilitate in the management of hepatitis B in Africa.

• DFG Programme: Research Grants
• International Connection: South Africa, Sudan
• Participating Person: Professor Dr. Wolfram H. Gerlich