Tuberculosis (TB).

Caused by Mycobacterium tuberculosis, a bacterium and a non-opportunistic infection found in non-HIV-infected people. Infects lungs, disseminated in some AIDS patients. A major killer in the past, social hygiene education and effective medical treatment eliminated TB from most of the Western world, except among populations lacking adequate access to medical care. Statistically associated with AIDS (found in some AIDS patients), it may reflect socio-economic status rather than being an opportunistic infection due to AIDS. Infection may occur prior to HIV infection as a damaged immune system is not required to catch TB.