Sample survey of drug-resistant tuberculosis in Henan, China, 1996

There is little reliable data on the global drug resistance to tuberculosis (TB) as most of the existing data is based upon biased samples, is not standardized or was obtained using poor techniques. For this reason, the World Health Organization (WHO) and the International Union Against Tuberculosis and Lung Disease (IUATLD) developed a global project on anti-TB drug resistance surveillance (DRS) in 1994. China joined this project in 1995 and the province of Henan was selected as the first site for collection of representative samples to survey the prevalence of drug-resistant TB.

Standard drug susceptibility testing by the proportion method against streptomycin (S), isoniazid (H), rifampicin (R), and ethambutol (E) was performed with Mycobacterium tuberculosis isolated from 916 new cases and 456 previously treated cases. Treatment outcome of these patients has been evaluated according to the regimens and drug susceptibility patterns.

Drug resistance among new cases to any drug was found to be 43.0% and any resistance: S, 32.5%; H, 31.0%; R, 20.7%; and E, 10.3%. Drug resistance among previously treated cases to any drug was 68.2% and any resistance: S, 52.2%; H, 49.3%; R, 48.3%; and E, 20.4%. The cure rate for new cases was 43.3% and 29.4% for previously treated cases. The poor cure rate resulted mainly from a high defaulter rate.

Drug-resistant TB was found to be highly prevalent in Henan and the cure rate remained poor. The results strongly indicated that Henan should take immediate action to improve the cure rate of patients through expansion of the introduction of the directly observed treatment short-course strategy.