Open Access Highly Accessed Research article

Prevalence of multidrug resistance in Mycobacterium tuberculosis isolates from HIV seropositive and seronegative patients with pulmonary tuberculosis in north India

Sunil Sethi1*, Abhishek Mewara1, Sunil Kumar Dhatwalia1, Harpal Singh1, Rakesh Yadav1, Khushwinder Singh1, Dheeraj Gupta2, Ajay Wanchu3 and Meera Sharma1

Author Affiliations

1 Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India

2 Department of Pulmonary Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, India

3 Department of Internal Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, India

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BMC Infectious Diseases 2013, 13:137  doi:10.1186/1471-2334-13-137

Published: 15 March 2013

Abstract

Background

Multidrug resistant (MDR) and extensively-drug resistant (XDR) tuberculosis (TB) are a serious threat to the national TB control programs of developing countries, and the situation is further worsened by the human immunodeficiency virus (HIV) pandemic. The literature regarding MDR/XDR-TB is, however, scanty from most parts of India. We carried out this study to assess the prevalence of MDR/XDR-TB in new and previously treated cases of pulmonary TB and in HIV seropositive and seronegative patients.

Methods

Sputum and blood specimens were obtained from 2100 patients suspected of pulmonary tuberculosis and subjected to sputum microscopy and culture for TB, and HIV serology at our tertiary care centre in north India. The culture positive Mycobacterium tuberculosis isolates were subjected to drug susceptibility testing (DST) for first line anti-tuberculosis drugs, and the MDR isolates were further subjected to second line DST. Various parameters of the patients’ were analyzed viz. clinical presentation, radiology, previous treatment history, demographic and socioeconomic data and microbiology results.

Results

Of the 2100 patients, sputum specimens of 256 were smear positive for acid-fast bacilli (AFB), 271 (12.9%) grew Mycobacterium spp., and M. tuberculosis was isolated in 219 (10.42%). Of the 219 patients infected with M. tuberculosis, 20.1% (44/219) were found to be seropositive for HIV. Overall, MDR-TB was observed in 17.4% (39/219) isolates. There were 121 newly diagnosed and 98 previously treated patients, of which MDR-TB was found to be associated with 9.9% (12/121) and 27.6% (27/98) cases respectively. There was significantly higher association of MDR-TB (12/44, 27.3%) with HIV seropositive patients as compared to HIV seronegative patients (27/175, 15.4%) after controlling previous treatment status, age, and sex (odd’s ratio, 2.3 [95% CI, 1.000-5.350]; p-value, 0.05). No XDR-TB was found among the MDR-TB isolates.

Conclusion

The present study demonstrated a high prevalence of drug resistance amongst pulmonary TB isolates of M. tuberculosis from north India as compared to the WHO estimates for India in 2010, though this could possibly be attributed to the clustering of more serious or referred cases at our tertiary care centre. The prevalence of MDR-TB in HIV seropositive patients was significantly higher than seronegative individuals. The study emphasizes the need to monitor the trends of drug resistance in TB in various populations in order to timely implement appropriate interventions to curb the menace of MDR-TB.

Keywords:
Mycobacterium tuberculosis; Multidrug resistant; Extensively-drug resistant; HIV; Socioeconomic status