Objective: To study the drug resistance profile of patients with suspected multidrug-resistant tuberculosis (MDR-TB).
Material and methods: This was a prospective study conducted among patients with suspected MDR-TB attending the Department of Respiratory Medicine, King George's Medical University, Lucknow, India, from August 2014 to April 2015. Sputum samples obtained from 50 such patients were subjected to drug susceptibility testing against first- and second-line drugs. Data on baseline characteristics were obtained from the patients and their previous medical records.
Results: Mycobacterium tuberculosis was detected in 47/50 (94%) and non-tuberculous mycobacteria (NTM) in 3/50 (6%). Of the 47 patients with M. tuberculosis, 36 (76.6%) had MDR-TB: 24 (66.7%) of these had pre-extensively drug-resistant TB (pre-XDR-TB) and 4 (11.1%) had XDR-TB.
Conclusions: Among proven MDR-TB cases, approximately two thirds were pre-XDR-TB cases and more than 10% were XDR-TB cases. These form a sizeable proportion and may result in the failure of second-line treatment.