Abstract: Sputum microscopy, the most commonly practiced tuberculosis (TB) diagnostic test is less sensitive in immunocompromised patients due to low bacillary load.The study was carried out in a tertiary care general hospital during 2010-12 in Mysore, Karnataka, to diagnose smear negative TB in HIV patients by culture technique.Of416 HIV patients, 162 patients with features of pulmonary/extrapulmonary TB but smear negative were included in the study.Sputum, stool, blood and other relavent clinical samplese except blood were processed as per standard protocol. The blood collected with sodium citrate was processed by lysiscentrifugation .All samples were inoculated onto Lowstein Jensen slants and incubated at 370c for 6 to 8 weeks.Of 162 HIV patients, 67(41%) were found to have TB. Extrapulmonary TB (25%) was more common than pulmonary TB (13%). Mycobacteria were recovered in 76 samples (26 sputum, 12 stool, 18 blood, 7 pleural fluid, 1 CSF, 9 FNAC, 1 ascitic fluid, 1pus ,1 ear discharge). M.tuberculosis (95%) was the predominant species isolated followed by M.avium complex (5%).Most HIV patients with TB are left undiagnosed for reasons of no advanced/high cost techniques in resource constrained settings. Thus culture could be used as a tool in diagnosing smear negative TB.
Keywords: Culture, HIV, Smear negative, Tuberculosis.
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