Declining trend of resistance to first-line anti-tubercular drugs in clinical isolates of Mycobacterium tuberculosis in a tertiary care north Indian hospital after implementation of revised national Tuberculosis control programme

Trends showing drug-resistance pattern are needed to understand direction of tuberculosis (TB) control programme. The drug-resistance pattern in state of Uttar Pradesh, India, is not documented. Here we are reporting the prevalence of multi-drug-resistant (MDR) and drug-resistant TB in previously treated cases of pulmonary tuberculosis following launch of revised national TB control programme (RNTCP) in whole of Uttar Pradesh. Isolates of Mycobacterium tuberculosis, from patients of pulmonary tuberculosis, who were treated with antitubercular drugs for more than 4 weeks, were tested for resistance to first-line drugs; streptomycin (S), Ethambutol (E), Rifampicin (R) and isoniazid (H) over a period of 4 years, 2009-2012. Total 2496 isolates of M. tuberculosis were tested, of which 1139 isolates (45.6%) were pan-sensitive and 370 (14.8%) were pan-resistant. Total 695 isolates (27.8%) were MDR. Maximum resistance was with Isoniazid (n = 1069, 42.8%) followed by streptomycin (n = 840, 33.7%), rifampicin (n = 742, 29.7%), and ethambutol (n = 613, 24.6%). A decline in number of MDR strains and individual drug resistance was seen. Total MDR strains in the year 2009, 2010, 2011 and 2012 were 35.6%, 30.8%, 26.7% and 22.8% respectively. The drug resistance pattern reported from time to time may vary substantially. The decline in drug resistance visible over last four years, after implementation of DOTS, appears promising.