Efficacy of genexpert in diagnosing MTB / RIF resistance in HIV seropositive and seronegative patients: a study in comparison

Aims and Objective: The aim of the present study is to compare diagnostic efficacy of Gene-X pert in HIV seropositive and HIV seronegative patients in detecting MTB in sputum and Rifampicin resistance and to treat MDR TB as early as possible so that patient can be initiated on DOTS-PLUS treatment promptly thereby reducing morbidity, mortality, occurrence of XDR and transmission of MDR in the community. Considering its public health importance present study was undertaken. Materials and Method: This is an observational, prospective study conducted over a period of 14 months (Jan 15 to April 16) in the Dept. of Pulmonary Medicine, Shree Vasantrao Naik Govt. Medical College, Yavatmal, Maharashtra, India. We subjected 659 patients, who fulfilled the clinical criteria for RNTCP - MDRTB suspect. viz 1)Treatment failure, 2)-Retreatment case sputum positive at the end of 4 months, 3) - Contact of known MDRTB case, 4) - Sputum positive at diagnosis, retreatment case, 5) - Any follow up sputum positive, 6) - Other category (sputum negative retreatment cases) and 7) - HIV-TB cases. With all safety precautions two samples were collected in the designated microscopy centre and subjected for routine ZN staining and Gene X-pert MTB/RIF assay. Study subjects were divided into Group-1(HIV sero-Positive) and Group-2 (HIV Sernegative). All new cases (sputum positive, sputum negative and extra-pulmonary cases) have been excluded from the domain of this study. Results: Total 659 patients were enrolled for the study at hand and were divided into 2 groups. In Group-1 (HIV seropositive) there were 157 patients, and in Group -2 (HIV seronegative) there were 502 patients. Mean age of the study population was 38.98 years. In group-1 Male to Female ratio was found to be 2.73:1 and in group-2 it was 2.28:1 respectively. In group-1(n=157) MTB detected in 59 patients out of these 3 patients were Rifampicin resistant and in Group-2(n=502) MTB detected in 302 patients out of which 43 were found to be Rifampicin resistant. Conclusion: Hence, it can be concluded that Gene Xpert is a useful tool in detecting MTB(P= 0.0002817) and Rifampicin resistance(P =0.004288) in HIV seropositive as compared to HIV seronegative patients.