Title: Diagnostic Role of Cartridge Based Nucleic Acid Amplification Test in Diagnosing Tuberculosis in Patients Co-infected with Human Immunodeficiency Virus
Authors: Prem Parkash Gupta, Adarsh B Mynalli, Aparna Yadav
DOI: https://dx.doi.org/10.18535/jmscr/v5i5.100
Abstract
Background: During recent years, disease caused by human immunodeficiency virus (HIV) and tuberculosis (TB) have been the two leading infectious diseases associated with mortality worldwide. The delays in diagnosis and initiation of anti-tubercular treatment often lead to increased transmission of TB in the community and spread to extrapulmonary sites within the patient. Our study aimed at to assess the role of CBNAAT in early diagnosis of TB in HIV patients and detection of M. tuberculosis in sputum by CBNAAT compared to conventional sputum microscopy in pulmonary TB
Methods: The study screened 211 patients with clinical symptoms suggestive of pulmonary tuberculosis. 30 subjects were found to be seropositive for HIV. Out of 30 HIV-TB patients, 20 were male. Direct microscopic sputum examination was done using Light Emitting Diode based Fluorescent Microscopy (LED-FM) method. All patients also submitted sputum sample for GeneXpert MTB/Rif test, a cartridge based nucleic acid amplification test (CBNAAT), analysed using GX4 system.
Results: LED-Fluorescent Microscopy sputum examination was positive for acid fast bacilli in 8/30 HIV seropositive patients and 131/181 subjects who were seronegative for HIV. The data suggested patients who were HIV positive were less likely to have sputum smear positive results. CBNAAT detected M. tuberculosis in 17/30 HIV-seropositive patients and in 133/181 HIV-seronegative subjects. 56.7% of the patients who were positive for HIV were also positive for MTB and two of them had rifampicin resistance detected by CBNAAT.
Conclusions: CBNAAT significantly increased the conclusive diagnosis of tuberculosis in patients co-infected with HIV, and additionally detected rifampicin resistance, thus providing huge leap in management of tuberculosis in HIV setting.
Keywords: Cartridge based nucleic acid amplification test, HIV, Tuberculosis, GeneXpert MTB/Rif test, Rifampicin resistance.
