Multidrug resistance in new tuberculosis patients: burden and implications.

In 2010, 30 countries with anti-tuberculosis drug resistance surveillance data were each estimated to have more than 700 multidrug-resistant tuberculosis (MDR-TB) cases among their notified TB cases. New TB patients comprised a median of 54% (interquartile range 45-67) of the MDR-TB cases. The occurrence of MDR-TB in a new TB patient is a warning sign that MDR-TB is spreading in a community. While MDR-TB case-finding efforts should first prioritize previously treated patients, reaching universal access requires rapidly adding other risk groups, and then all new TB patients. Epidemiological data as presented in this paper can help inform country scale-up plans.