Decline in rates of acquired multidrug-resistant tuberculosis after implementation of the directly observed therapy, short course (DOTS) and DOTS-Plus programmes in Taiwan

Abstract

To investigate the impact of the directly observed therapy, short course (DOTS) and DOTS-Plus strategies on changes in resistance profiles among Mycobacterium tuberculosis (MTB). We performed a retrospective analysis of resistance profiles among isolates of MTB obtained from 2160 consecutive patients with culture-confirmed pulmonary tuberculosis (TB) between 2005 and 2011 at a referral centre in southern Taiwan. Of the 2160 patients, 70 (3.2%) had primary multidrug-resistant (MDR)-TB, 178 (8.2%) had acquired MDR-TB, 10 (0.5%) had primary extensively drug-resistant (XDR)-TB, 23 (1.1%) had acquired XDR-TB and 5 (0.2%) had totally drug-resistant (TDR)-TB. Trend analysis revealed that the rates of acquired MDR-TB were significantly lower after implementation of the DOTS and DOTS-Plus programmes (P < 0.01). There was a significant negative correlation between the coverage rates of the DOTS and DOTS-Plus programmes and the rates of acquired MDR-TB (r = -0.84, P = 0.02 and r = -0.92, P = 0.03, respectively). The rates of resistance to rifampicin, isoniazid, ofloxacin, moxifloxacin, levofloxacin and para-aminosalicylic acid also decreased significantly during the study period. However, the rates of primary MDR-TB remained stable (P = 0.11). Multivariate logistic regression analysis showed that age ranging from 45 to 64 years, positive acid-fast stain results at the initiation of treatment and treatment without DOTS were independent risk factors associated with acquired MDR-TB. In addition, previous treatment for TB (100% versus 19% for TDR-TB and non-TDR-TB, P < 0.01) and treatment without DOTS (80% versus 44% for TDR-TB and non-TDR-TB, P = 0.18) were risk factors for TDR-TB. DOTS and DOTS-Plus are both effective at preventing the acquisition of MDR-TB in Taiwan.