Study of drug resistance in pulmonary tuberculosis cases in south coastal Karnataka

The present cross-sectional study was conducted for the first time from the Udupi district of coastal Karnataka to know the prevalence of drug resistance and comparative analysis of MDR and non-MDR cases of pulmonary tuberculosis. Details of 862 smear positive cases of pulmonary tuberculosis with age ≥15 years from 12 designated microscopy centres of the Udupi district were studied. Initially 2 sputum samples trailed by one follow-up sample were collected from each patient and processed for culture and drug sensitivity on the Lowenstein-Jensen medium. A total resistance of 33.4% was observed that includes the mono-resistance of 22.5%, multidrug resistance (MDR) of 6.3% and extensive drug resistance (XDR) of 0.3%. Significant odds ratio (OR) was observed in category 2 cases (OR 3.9) for the development of MDR tuberculosis. A significant statistical association was observed using Fisher's exact test while comparing mortality rate (19.3% vs. 1.8%), treatment failure (8.8% vs. 3.8%) and cure rate (68.4% vs. 85.4%) between MDR and non-MDR cases (p < 0.001). Category 2 patients are important risk factors for the development of MDR in pulmonary tuberculosis. Due to high mortality and low cure rate in MDR cases it is imperative to know the drug sensitivity report before institution of anti-tubercular treatment.