Prevalence of mycobacteremia in Indian HIV-infected patients detected by the MB/BacT automated culture system.
The use of automated blood cultures system, such as MB/BacT, has provided a novel opportunity for laboratories to diagnose mycobacteremia in HIV-infected patients. However, no such study has been carried out in India so far. This prospective study was conducted on 52 HIV-positive patients with suspected tuberculosis who were referred to our tertiary care hospital in New Delhi. In these patients, the prevalence of mycobacteremia was evaluated using the MB/BacT automated culture system (bioMérieux, France). Twenty-seven HIV-negative but suspected tuberculosis patients were also included for comparison. Mycobacteria could be isolated from sputa or fecal samples of 20 HIV-positive patients (38.4%), and in nine (45%) of these 20 cases, mycobacteria could also be isolated simultaneously from their blood specimens. In the remaining 32 patients, all relevant non-hematological clinical samples remained negative for mycobacteria, but the pathogen could be detected from the blood samples of seven (21.87%) of these 32 patients. Therefore, only 25 (48%) clinically suspected patients remained negative in both Löwenstein-Jensen (L-J) and MB/BacT culture methods, and 12 of these responded to anti-tubercular treatment, while in the rest either non-tubercular diagnosis was established or they were lost to follow-up. The study revealed that low CD+(4) counts and poor or no reactivity to purified protein derivative (PPD) were the best clinical predictors for the occurrence of mycobacteremia in HIV-positive patients. Of the 16 isolates from blood, 13 were diagnosed as Mycobacterium tuberculosis and one each were identified as M. avium, M. kansasii, and a mixed infection of M. tuberculosis and M. avium complex. The prevalence rate of mycobacteremia was significantly low (11.1%) in HIV-negative patients. In conclusion, this study showed that blood culture could be an important adjunct investigation for confirming the clinical diagnosis of tuberculosis in HIV-positive patients.
Gopinath
K
K
Division of Clinical Microbiology, Department of Laboratory Medicine, All India Institute of Medical Sciences (AIIMS), Ansari Nagar, New Delhi, India.
Kumar
S
S
Singh
S
S
D000328:Adult; D016470:Bacteremia / Q000097:blood / Q000453:epidemiology*; D001431:Bacteriological Techniques / Q000295:instrumentation*; D005006:Ethnicity; D005260:Female; D015658:HIV Infections / Q000150:complications* / Q000382:microbiology; D006679:HIV Seropositivity; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009164:Mycobacterium Infections / Q000453:epidemiology*; D015269:Mycobacterium avium Complex / Q000145:classification / Q000302:isolation & purification; D009169:Mycobacterium tuberculosis / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D015995:Prevalence; D011446:Prospective Studies; D011933:Reagent Kits, Diagnostic
D011933:Reagent Kits, Diagnostic