Prevalence of Mycobacterium avium and Mycobacterium tuberculosis in blood cultures of Brazilian AIDS patients after introduction of highly active retroviral therapy

The use of highly active antiretroviral therapy (HAART) for the treatment of HIV infection has been associated with a marked reduction in the incidence of most opportunistic infections. From April 2001 to February 2002, 80 blood samples from patients who were suspected to have disseminated mycobacterial infection, presenting fever and (preferably) a CD4 T cell count < 100.0 cell/mL were investigated. Twelve (15%) of the 80 blood cultures were positive for mycobacteria, with Mycobacterium avium being identified in 7 (8.8%) samples and M. tuberculosis in 5 (6.2%). The TCD4+ count at the time of M. avium bacteremia ranged from 7 cells/microL (average of 48.5 cell/microL), while in M. tuberculosis bacteremia it ranged from 50.0 cells/microL (average of 80.0 cell/microL). The prevalence of M. avium bacteremia in our study follows the expected decline in opportunistic infections observed after the introduction of HAART; however, mycobacteremia by M. tuberculosis still indicates a high prevalence of tuberculosis infection in AIDS patients.