2010 Oct - Multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis (TB) in Hong Kong: 5 years follow up study
Dr. LEUNG Wai Man, TB & Chest Service, Department of Health
1) To assess the treatment outcomes of MDR-TB and XDR-TB patients between 1, January 1997 to 31, December 2003 and the associated factors affecting the treatment outcomes. 2) To assess the relapse rate.
All consecutive patients found in the MDR-TB registry in TB and Chest Service, Department of Health, Hong Kong from 1, January 1997 to 31, December 2003 were enrolled retrospectively, with their treatment outcomes at the end of treatment were classified according to Laserson’s definition. Patients were followed up for 5 years to assess any relapse.
211 MDR-TB patients were enrolled. 23 (11%) were XDR-TB patients. 132 patients (63%) achieved favorable outcome (cured or completed treatment), 13 (6%) died, 45 (21%) defaulted, 7 (3%) with treatment failure and 14 (7%) transferred out. 124 (66%) non XDR-TB patients versus 8 (35%) XDR-TB patients achieved favorable outcome (p=0.004). On multivariate analysis and subgroup analysis, favourable outcome was associated with absence of adverse social factor (OR=2.172, 95% CI=1.091-4.322) and use of 4 or more susceptible drugs (OR=4.168, 95% CI=1.052-16.515). Unfavourable outcome was associated with resistance to any second line injectable drug (OR= 0.274, 95% CI=0.120-0.625), disease extent greater than a right lung equivalent (OR=0.165, 95% CI=0.030-0.907) and use of experimental drugs (OR=0.175, 95% CI=0.046-0.671). 8 out of 132 (6%) patients with favourable outcomes had relapsed during the 5-year follow up. 2 out of 8 relapses were XDR-TB patients.
XDR-TB patients had a poorer outcome than other MDR-TB patients. Absence of adverse social factor and used of 4 or more effective drugs were associated with favourable outcome. In vitro resistance to any second line injectable drug, use of experimental drugs and disease extent greater than right lung equivalent were associated with unfavourable outcome. MDR-TB relapse is not uncommon.