The Interaction of Tuberculosis and HIV in Africa

HIV infection affects 34 million of the world population and Tuberculosis (TB) affects 15 million. The greatest burden of both diseases is in sub Saharan Africa [1]. In high HIV prevalence countries in sub Saharan Africa TB notifications have increased over 20 years from 1990 to 2009 [2]. According to the WHO world report in 2009, HIV associated TB cases accounted for 78% of the total cases in Africa yet in South East Asia it was only 13% [3]. Clearly high HIV prevalence rates are associated with high TB prevalence rates, to the extent that HIV infected people are 20 to 30 times likely to develop TB [4]. In addition, HIV-associated TB contributes disproportionately to TBrelated deaths. In 2008, there was 37% estimated case fatality due to TB among HIV infected people while HIV uninfected accounted for 16% [3]. The probable reasons for such high case fatality rates include rapid progression of disease in HIV infected individuals and, delayed diagnosis of both HIV and TB. There is also a delay in accessing combination antiretroviral therapy and higher rates of multidrug resistant TB in HIV infected patients [3].