Abstract
This study was conducted to find out the prevalence and pattern of primary and acquired resistance to antimycobacterial drugs among patients of pulmonary tuberculosis, in Armed Forces. Out of 2562 clinically diagnosed patients of tuberculosis, in a span of three years, 1146 were bacteriologically positive. The study included only 1120 smear and culture positive cases, and excluded 26 cases in which no growth was obtained on culture. 192 out of 1120 cases (17.14%), showed overall resistance to one or more antituberculous drugs (ATD). Primary drug resistance (PDR) was observed in 161 (14.37%) and acquired drug resistance (ADR) in 31 isolates (2.77%). Of the resistant cases on short course chemotherapy (SCC), single drug resistance was observed in 99 (51.56%), resistance to any two drugs in 63 (32.81%), and three or more drugs in 30 (15.62%) cases. Analysis of resistance to specific drug revealed 26.56% for streptomycin (S), 15.10% for rifampicin (R), 7.29% for isoniazid (H), 2.08% for pyrazinamide (P) and 0.52% for ethambutol (E). Resistance to H and R was present in 4.16% strain and their combination with other drugs resistance was in 16.14% of the drug resistant strains, thus constituting 2.76% of the total sputum positive cases. A group of 26 cases is also discussed, where there was discrepancy in clinical status and bacteriological parameters and treatment for multi-drug resistant tuberculosis (MDR-TB) was instituted.