Mycobacteraemia among HIV-1-infected patients in São Paulo, Brazil: 1995 to 1998.

From July 1995 to August 1998, mycobacterial blood cultures were obtained from 1032 HIV-infected patients seen at the Centro de Referência e Treinamento de AIDS (CRTA), Hospital São Paulo (HSP), and Centro de Referência de AIDS de Santos (CRAS). Overall, 179 episodes of mycobacteraemia were detected: 111 (62.0%) at CRTA, 50 (27.9%) at HSP, and 18 (10.1%) at CRAS. The frequency of positive cultures declined sharply from 22.6% in 1995 to 6.9% in 1998, consistent with the decrease in opportunistic infections following the publicly funded distribution of highly active antiretroviral therapy. In 1995, mycobacteraemia was more frequently due to Mycobacterium avium complex (59.2%) than Mycobacterium tuberculosis (28.6%), whereas in 1998 the relative frequencies were reversed (28.6 vs. 64.3% respectively), probably justified by the increased virulence of M. tuberculosis and the greater risk of invasive infection in less-immunocompromised patients, including patients unaware they are infected with HIV.