PLoS ONE (Jan 2015)

Resistance patterns among multidrug-resistant tuberculosis patients in greater metropolitan Mumbai: trends over time.

  • Alpa Dalal,
  • Akshay Pawaskar,
  • Mrinalini Das,
  • Ranjan Desai,
  • Pralhad Prabhudesai,
  • Prashant Chhajed,
  • Sujeet Rajan,
  • Deepesh Reddy,
  • Sajit Babu,
  • T K Jayalakshmi,
  • Peter Saranchuk,
  • Camilla Rodrigues,
  • Petros Isaakidis

DOI
https://doi.org/10.1371/journal.pone.0116798
Journal volume & issue
Vol. 10, no. 1
p. e0116798

Abstract

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BACKGROUND:While the high burden of multidrug-resistant tuberculosis (MDR-TB) itself is a matter of great concern, the emergence and rise of advanced forms of drug-resistance such as extensively drug-resistant TB (XDR-TB) and extremely drug-resistant TB (XXDR-TB) is more troubling. The aim of this study was to investigate the trends over time of patterns of drug resistance in a sample of MDR-TB patients in greater metropolitan Mumbai, India. METHODS:This was a retrospective, observational study of drug susceptibility testing (DST) results among MDR-TB patients from eight health care facilities in greater Mumbai between 2005 and 2013. We classified resistance patterns into four categories: MDR-TB, pre-XDR-TB, XDR-TB and XXDR-TB. RESULTS:A total of 340 MDR-TB patients were included in the study. Pre-XDR-TB was the most common form of drug-resistant TB observed overall in this Mumbai population at 56.8% compared to 29.4% for MDR-TB. The proportion of patients with MDR-TB was 39.4% in the period 2005-2007 and 27.8% in 2011-2013, while the proportion of those with XDR-TB and XXDR-TB was changed from 6.1% and 0% respectively to 10.6% and 5.6% during the same time period. During the same periods, the proportions of patients with ofloxacin, moxifloxacin and ethionamide resistance significantly increased from 57.6% to 75.3%, from 60.0% to 69.5% and from 24.2% to 52.5% respectively (p<0.05). DISCUSSION:The observed trends in TB drug-resistance patterns in Mumbai highlight the need for individualized drug regimens, designed on the basis of DST results involving first- and second-line anti-TB drugs and treatment history of the patient. A drug-resistant TB case-finding strategy based on molecular techniques that identify only rifampicin resistance will lead to initiation of suboptimal treatment regimens for a significant number of patients, which may in turn contribute to amplification of resistance and transmission of strains with increasingly advanced resistance within the community.