Influence of drug susceptibility on treatment outcome and susceptibility profile of failures to category II regimen.

ABSTRACT

Objective: To assess the influence of drug resistance on treatment outcome among patients treated with Category-II regimen and document drug susceptibility pattern of “Failures” to this regimen. Design: A retrospective analysis of patients registered from May 1999 through December 2004. Results: Treatment success was 42% among 572 patients and was similar among patients with fully susceptible or resistant but non-MDR organisms (41% of 254 and 40% of 128 patients, respectively). Among 49 MDR-TB patients, 27% had successful treatment outcome. The failure rates among patients with fully susceptible, resistant but non-MDR and MDR bacilli, were 6%, 12% and 27% respectively. Default was significantly higher among males (53% vs. 34% p<0.01) smokers (57% vs. 36% p <0.001), alcoholics (58% vs. 39% p <0.001) and patients with higher initial smear grading (2+ or 3+, 56% vs. scanty or 1+, 44% p <0.01). DST results were available for 60% (31 of 52) of failures and 10 had MDR-TB. Conclusion: The low success rate to the re-treatment regimen was mainly due to non-compliance. Failure was observed among 9% of patients and MDR-TB was 32% among Category II failures. The currently recommended Category II regimen appears to be adequate for majority of re-treatment cases.