TB and HIV coinfection- GeneXpert a comparable tool to Line probe assay for diagnosis of MDR TB

Abstract

Introduction: Tuberculosis (TB) and HIV duo forms the deadly synergy- the patients with these diseases more often will have unfavourable outcomes. It is important to see HIV TB correlation ad drug resistance in case of tuberculosis. Aims and objectives:
1. To detect HIV seropositivity in newly diagnosed sputum smear positive pulmonary tuberculosis patients.
2. To detect rifampicin resistance by CBNAAT.
3. To detect drug resistance of first and second line antitubercular drugs by conventional methods.
4. Comparison of drug resistance of Mycobacterium tuberculosis isolates in patients with and without HIV.
Material and methods: Prospective, cross sectional study was conducted in department of microbiology for one and half year. 200 newly diagnosed sputum positive samples were collected. They were subjected to Zeil Nelson(ZN) staining, culture, culture on Loweinstein Jensen(LJ)media, GeneXpert and Line Probe Assay(LPA). HIV test was done on blood sample. Results: Out of 200 patients, 123(61.5%) were males and 77(38.5%) were females. Male: Female ratio was 1.7:1. HIV positive were 12.5% and HIV negative were 87.5%. 65% showed growth on LJ media. 85% were positive by CBNAAT. Out of 25 HIV positive cases 48% were detected by CBNAAT. 2.35% were resistant to rifampicin. On LPA, all drugs that were resistant to rifampicin, were also resistant to isoniazid but sensitive to other second line drugs’. Conclusion: HIV testing of patients with TB and susceptibility testing of M. tuberculosis isolates from HIV-infected patients should be routine in settings where outbreaks or endemic transmission of MDR-TB is occurring in HIV-infected patients.