”In 1994, due to lack of standardized data on anti-TB drug resistance and in an effort to estimate the global prevalence of resistance, WHO, International Union Against Tuberculosis and Lung Disease (IUATLD) and other partners developed the  

(DRS).

The project assembled a network of Supranational Reference Laboratories (SRLN- Supranational Laboratory Network) to aid National Reference Laboratories in conducting quality assured drug susceptibility testing in conjunction with national or area

anti-TB drug resistance surveillance. The project is now expanding implementation of surveys to new countries prioritizing countries with a high burden of TB, or suspected high prevalence of MDR, incorporating more rigorous surveillance of

retreatment cases to determine prevalent resistance patterns, repeating surveys every three to five years in order to observe trends, and expanding objectives of surveillance to include operational research where capacity has been demonstrated.”