[Disseminated mycobacterial infections in patients with HIV/AIDS. Evaluation of blood cultures].

One thousand-forty blood cultures corresponding to 451 Uruguayan patients with AIDS and clinic diagnosis of disseminated mycobacterial infection were evaluated between 1999 and 2003. Samples were processed in the National Reference Center for Mycobacteria (Montevideo, Uruguay), using the automated blood culture system for mycobacteria MB-BacT (BioMérieux). Forty-five positive samples were detected (4.3%) corresponding to 26 patients with AIDS (average 2.3 samples per patient). In 10/26 patients M. avium complex (MAC) was identified and in 13/26 the isolated germ was M. tuberculosis. The average time of incubation was of 12.4 days (range 6-19 days) for MAC and of 22.6 days (range 7-35 days) for M. tuberculosis. Blood culture has demonstrated to be the best sample for the bacteriological confirmation of the disseminated mycobacterial infections when at least 2 samples by patient are studied. The frequency of isolates of M. tuberculosis and MAC in AIDS patients is according with a moderate prevalence of tuberculosis in Uruguay.