Worldwide incidence of multidrug-resistant tuberculosis.

Planning for tuberculosis (TB) control requires an assessment of the number and distribution of drug-resistant cases. This study used results of resistance surveys from 64 countries, together with data predictive of resistance rates from 72 others, to estimate the number of new multidrug-resistant (MDR) TB cases that occurred in 2000. By these methods, an estimated 273,000 (95% confidence limits, 185,000 and 414,000) new cases of MDR TB occurred worldwide in 2000, 3.2% of all new TB cases. The analysis provides the first comprehensive set of estimates of the MDR TB burden by country and globally.