Drug Susceptibility Pattern of M.Tuberculosis Isolated from Patients Attending a Private Hospital

Abstract

Problem statement: Drug resistance in Tuberculosis (TB) is an emerging problem that adversely affects patient outcome and public health in the developing world. Although much of tuberculosis care is provided by the private sector in India, the magnitude of drug resistance in TB in the private sector is not well described. The present study was carried out to determine the resistance pattern of tuberculosis in patients attending a large tertiary care hospital in South India. Approach: Anti-tuberculosis resistance patterns of all Mycobacterium tuberculosis (M.tb) isolates in a tertiary care referral hospital from January 2010 to December 2010 were studied retrospectively. Isolates were grown in MB/BacT automated liquid culture system. Sensitivities to various anti-tuberculosis drugs were done by the proportion method on Lowenstein-Jensen (L-J) media. Results: During the study period, sensitivity reports for 50 Mycobacterium isolates were available.14 (28%) of the isolates were multi-drug resistant isolates (resistant to both isoniazid and rifampicin). Isolated resistance to isoniazid, rifampicin, ethambutol, pyrazinamide and streptomycin were 42, 32, 28, 48.28 and 44% respectively. Moxifloxacin was tested against only 12 tuberculosis isolates and was uniformly sensitive against all isolates tested. Conclusion: Nearly one third of M.tb isolates in a private sector tertiary care hospital were multi-drug resistant. Isolated resistance to ethambutol was the lowest among the first line anti-tuberculosis drugs and resistance to moxifloxacin was not seen in this study. Even allowing for referral bias, our results suggest that tertiary care hospitals which see complicated tuberculosis patients should routinely ask for susceptibility tests whenever M.tb is cultured.