Tuberculosis is a frequent complication in human immunodeficiency virus [HIV] patients. We studied the clinical characteristics, therapy, and outcome of patients with Mycobacterium tuberculosis (MTB) bacteremia.
From 1984–2002, 60/3675 HIV patients were diagnosed with active MTB. Demographics data and cultures for MTB were noted; including all lysis-centrifugation blood cultures (LC-BC). Mycobacterial isolates and subspecies were identified from blood cultures (BC) using the Genprobe Isolation system.
Mean age was 39 years [46 males; 14 females]. LC-BCs were positive for MTB in 11 patients. ( 18.3%). Bacteremic MTB patients had lower CD4 (mean CD4 56.2 cells/mm3 [range 1–330]) compared to nonbacteremic MTB patients [152 cells/mm3; range 52–762]) p<0.05(Mann-Whitney test)]. 9/24 patients with CD4 <50 cells/mm3 had a positive BC for MTB in contrast to 2/36 patients with a CD4 >50cells/mm3. There was no association between positive BC and any of the demographic/risk factors for HIV transmission. Four patients had concomitant other mycobacterial infections [3 MAI diagnosed in sputum and one with M kansasaii concomitantly in blood]. MTB was isolated from sputum in 10/11 bacteremic patients. Concomitant bacteremia with nonmycobacterial organisms was noted in patients with CD 4 < 50 [11/ 24 vs 7/ 36 in patients with CD4>50]. 3/11 bacteremic patients died in contrast to 5/36 nonbacteremic patients.CONCLUSIONS: MTB bacteremia is common among adults with advanced HIV infection occurring at an advanced stage of HIV when the CD 4 cell counts are <50 cells/mm 3. LC-BC is particularly helpful in making a diagnosis of MTB in HIV patients with low CD4 counts especially when cultures from other sites remain negative. LC-BC growing MTB indicate more severe and disseminated MTB and provides an extremely useful source of MTB for drug sensitivity testing for appropriate management of MTB in HIV.
In severely immunosuppressed patients multiple LC-BC are required for the diagnosis of MTB, for drug sensitivity testing, and to establish the diagnosis of other mycobacterial coinfections.
M. Desruisseaux, None.