Mycobacterium tuberculosis bacteremia in a university hospital

SETTING: Patients with blood cultures positive for Mycobacterium tuberculos is between 1988 and 1999. OBJECTIVE: To study the clinical and microbiological characteristics of pat ients with tuberculous bacteremia, including data about evolution and manag ement. DESIGN: Retrospective review of the clinical charts and microbiological rec ords of patients with culture-proven tuberculous bacteremia between 1988-19 99. RESULTS: During the study period, 19 patients with culture-proven M. tuberc ulosis bacteremia were detected (1.42 isolates/patient, 4.7% of all patient s with blood cultures for mycobacteria). Four patients were noninfected wit h the human immunodeficiency virus and 15 were HIV-infected. In four patien ts blood was the only positive sample. Five patients were diagnosed simulta neously with tuberculosis and HIV infection. Only 13 had a temperature high er than 37.5 degreesC. Most patients had symptoms or signs of respiratory t ract involvement, and 11 patients died (10 from tuberculosis). The average time for detection of positive blood cultures was 33.25 days for lysis-cent rifugation cultures and 26.46 days for BACTEC cultures. The incidence of M. tuberculosis bacteremia remained stable during the study period. CONCLUSIONS: Although blood cultures are useful for definitive diagnosis of disseminated tuberculosis, the long incubation times made them of limited usefulness in the clinical management of patients. Mortality remains high i n these patients.