Childhood drug-resistant tuberculosis in the Western Cape Province of South Africa

Abstract

Aim: Continued surveillance of drug resistance amongst children presenting with culture-confirmed tuberculosis to a tertiary care hospital and to community clinics.

Methods: Drug susceptibility testing for isoniazid and rifampicin was prospectively done on all children presenting with culture-confirmed tuberculosis from three study populations: children diagnosed at Tygerberg Children's Hospital in the Western Cape Province, South Africa, between March 2003 and February 2005 (recent survey, hospital-based group), and August 1994 and April 1998 (previous hospital-based survey), and a community-based group from five clinics during the recent survey.

Results: Isoniazid resistance increased significantly from 6.9% (21/306 children) in the previous survey to 12.8% (40/313 children) in the recent survey (odds ratio (OR) 1.99, 95% confidence interval (CI) 1.11-3.59). Resistance to isoniazid and rifampicin (multidrug resistance) did not increase significantly between the surveys (7/306 in previous survey vs 17/313 in recent survey; OR 2.45, 95% CI 0.94-6.62). All resistance (isoniazid and/or rifampicin) was 18/127 (14.2%) in the community-based group compared to 23/192 (12.0%) in the hospital-based group (OR 0.82, 95% CI 0.41-1.68).

Conclusion: The prevalence of drug-resistant tuberculosis in this setting is increasing, reflecting ongoing transmission of drug-resistant Mycobacterium tuberculosis.