Resistance patterns among multidrug-resistant tuberculosis patients in greater metropolitan Mumbai: trends over time
A retrospective, observational study of drug susceptibility testing results among MDR-TB patients from 8 health care facilities
Abstract
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 8 health care facilities in greater Mumbai between 2005 and 2013. We classified resistance patterns into 4 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.
This research was supported by the UK Department for International Development’s Operational Research Capacity Building Programme led by the International Union Against TB and Lung Disease (The Union)
Citation
Dalal A, Pawaskar A, Das M, Desai R, Prabhudesai P, Chhajed P, et al. (2015) Resistance Patterns among Multidrug-Resistant Tuberculosis Patients in Greater Metropolitan Mumbai: Trends over Time. PLoS ONE 10(1): https://doi.org/10.1371/journal.pone.0116798