First Line Anti-TB Drug Resistance in an Urban Area of Odisha, India.

Introduction: Drug resistance is a major cause for increasing the global burden of Tuberculosis (TB). However in countries with larger geographical areas and different climatic conditions like India the prevalence of drug resistance varies from place to place. Information on anti-TB drug resistance patterns particularly among newly diagnosed cases is crucial for planning an effective TB control program.

Aim: To determine the prevalence of resistance against first line anti-TB drugs and Multi Drug Resistance (MDR) in isolates.

Materials And Methods: The prospective study was carried out in National Reference Laboratory (NRL) of Regional Medical Research Centre (RMRC), Bhubaneswar. During this period from January to September 2014, sputum specimens were collected from 850 suspected pulmonary TB patients attending Designated Microscopy Center (DMC) of Capital Hospital, Bhubaneswar, Odisha. Sputum specimens were subjected to Acid Fast Bacilli (AFB) smear microscopy and further processed for isolation on solid Lowenstein Jensen (LJ) medium. Drug Susceptibility Testing (DST) on isolates with first line anti-TB drugs was performed as per Revised National Tuberculosis Control Programe (RNTCP) guidelines.

Results: Out of all the 850 suspected pulmonary TB patients subjected to AFB microscopy and solid LJ culture, isolation of was successful only in 161 (117 new and 44 previously treated) pulmonary TB patients. On DST by the RNTCP approved proportion method, prevalence of MDR- TB among 0.85% new and 4.54% previously treated cases was observed. Prevalence of mono resistance to streptomycin, isoniazid, rifampicin and ethambutol observed among new and previously treated cases were 3.41%, 2.56%, 0, 0.85% and 2.27%, 13.6%, 2.27%, 0 respectively. Only one patient from each category showed resistance to both streptomycin and isoniazid in previously treated as well as in new case.

Conclusion: The study reports an unchanged low level of MDR-TB prevalence among new cases in an urban area of Odisha over a decade. This could be due to the success of Directly Observed Treatment Short-course (DOTS) in effective treatment of drug-susceptible TB in the state and non-transmission from primary Drug Resistance (DR) TB cases.