MYCOBACTEREMIA IN PATIENTS WITH THE ACQUIRED-IMMUNODEFICIENCY-SYNDROME

Background: Bacillemia is a key event in the pathogenesis of tuberculo sis. Although current evidence indicates that Mycobacterium tuberculos is bacteremia is rare in patients seronegative for the human immunodef iciency virus, it has been increasingly reported in patients with the acquired immunodeficiency syndrome (AIDS). Objective: To determine cli nical and laboratory characteristics of patients with AIDS and tubercu losis with and without bacillemia. Methods: Fifty patients with AIDS w ith clinical suspicion of disseminated mycobacterial disease were pros pectively selected. Three consecutive blood samples were collected for culture using a standardized protocol. Results: Mycobacterium was iso lated from any body site in 42 patients (84%). Bacillemia was detected in 30 (71.4%) of these 42 patients: 11 (28.2%) caused by Mycobacteriu m avium-intracellulare complex and 19 (71.8%) caused by M tuberculosis . Blood culture was the only method used to confirm the diagnosis in 5 (15%) of the 33 tuberculosis cases. Tuberculosis in patients with AID S developed with nonspecific insidious symptoms, a remarkable elevated alkaline phosphatase level, and without the classic miliary radiologi cal pattern. We could demonstrate 2 previously unrevealed clinical cha racteristics of bacteremic tuberculosis in patients with AIDS: a shift to the left in the white blood cell count and abdominal lymph node en largement. In patients with tuberculosis, the in-hospital mortality ra te was higher among patients with bacillemia, although the posttreatme nt survival rate was comparable. Conclusions: Blood culture is a valua ble tool to confirm the clinical diagnosis of disseminated tuberculosi s in patients with AIDS and can distinguish patients with characterist ic clinical findings and outcome. Abdominal ultrasonography may be an additional helpful tool to identify these patients.