Multidrug-resistant tuberculosis (MDR-TB) has been recorded at the highest rates ever, according to this new report that presents findings from the largest survey to date on the scale of drug resistance in tuberculosis.This fourth global report is based on information collected between 2002 and 2006 on 90,000 TB patients in 81countries. It also found that extensively drug-resistant tuberculosis (XDR-TB), a virtually untreatable form of therespiratory disease, has been recorded in 45 countries. The primary aim of this report is to share survey and surveillance data on drug resistance in TB. The data presented here are supplied largely by the program managers who have led the work on surveys, but also heads of reference laboratories as well as principle investigators that may have been hired to assist the national Tuberculosis Program with the study.