HIV-Associated tuberculosis: A sub-saharan african perspective

The sub-Saharan Africa bears the brunt of being the region with the highest burden of both Human Immunodefiency Virus (HIV) infection and of tuberculosis (TB). While only 10% of immunocompetent individuals infected with M.tuberculosis go on to develop active disease in their lifetime, 50% of those co-infected with HIV develop active TB. Qualitative and quantitative defects of CD4+ T-lymphocytes explain the inability of HIV-infected individuals to contain mycobacterial proliferation. Similarly, TB also accelerates the progression of HIV infection. The clinical and radiological presentation of TB in patients infected with the HIV virus may be different and atypical posing significant diagnostic challenges. This is compounded by the dearth of diagnostic facilities in sub-Saharan Africa. The initiation of antiretroviral therapy (ART) during anti-TB therapy (ATT) significantly improves survival of TB/HIV co-infected persons. There are challenges in treatment of HIV associated TB because of overlapping drug toxicities, pill burden and suboptimal adherence, drug-drug interactions between ART and ATT as well as timing of ART. Of particular importance are the immune reconstitution inflammatory syndrome (IRIS) and the emergence of multi-drug resistant (MD-R) and extensively drug resistant (X-DR) TB. Centre's for tuberculosis diagnosis and treatment and for HIV care and treatment need to be integrated. This has not been so successful in sub-Saharan Africa. In spite of sustained support by donor organizations, a substantial number of HIV-TB co-infected individuals remain undiagnosed and are poorly managed. This review focuses on the epidemiology and pathogenesis of HIV-TB co-infection and the special areas of difficulty in the diagnosis and treatment of the dual infection. Emphasis is placed on the peculiarities of management in sub-Saharan Africa, the region with the highest burden of both infections.