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

Background: 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.