Drug susceptibility pattern of Mycobacterium tuberculosis isolates from patients of category-II failure of pulmonary tuberculosis under directly observed treatment short-course from north India

The major contributing factors for the causation of treatment failure in cases of pulmonary tuberculosis under Category-II directly observed treatment short-course treatment (DOTS) are treatment after default, poor treatment compliance, and development of multi-drug resistant (MDR) tuberculosis. The objective of the present study is to find out the demographic profile and drug susceptibility pattern in Category-II failure patients of pulmonary tuberculosis under Revised National Tuberculosis Control Programme (RNTCP) of India. Two hundred and twenty four patients with Category-II treatment failure of pulmonary tuberculosis were enrolled from Department of Pulmonary Medicine, at Chatrapati Sahuji Maharaj Medical University, UP, Lucknow, India, from August 2003 to July 2008. Their complete bacteriological assessment in terms of sputum smear for acid-fast bacilli, culture for Mycobacterium tuberculosis and drug sensitivity pattern were done in the Department of Microbiology. Among 224 patients, 16 (7.1%) patients were lost to follow-up and the final analysis was done among 208 (92.8%) cases. The reasons for inclusion of these 224 cases in the Category II regimen were treatment failure in the previous regimen (n = 75, 33%), default in 57% (n = 129 cases), and relapse in 8.9% (n = 20 cases). Among 208 patients, culture was positive in 170 (81.7%) cases, negative in 17 (8.1%) cases and contaminated in 21 (10%) cases. The drug sensitivity pattern of culture positive cases of Category-II failure patients revealed that, 58.2% (n = 99) had MDR tuberculosis and 40.5% (n = 69) were resistant but were non-MDR tuberculosis and 1.1 % (n = 2) cases were sensitive to all first line antituberculosis drugs.