One in three HIV-infected people worldwide is coinfected with the TB bacterium. TB is responsible for the death of one out of every three people with HIV/AIDS worldwide. People who are HIV-positive and infected with TB are 30 times more likely to develop active TB than people who are HIV-negative.
The TB bacterium enhances HIV replication and might accelerate the natural progression of HIV infection. Because of the increased spread of HIV in sub-Saharan Africa, the number of TB cases in that region will double to 4 million new cases per year soon after 2005. Almost half of HIV patients in sub-Saharan Africa develop active TB, whereas only 5% to 10% of individuals infected with TB and not infected with HIV develop active TB.