Screening and Primary Prevention The U.S. Preventive Services Task Force5

early one third of the world’s population is infected with Mycobacterium tuberculosis.1 More than one half of all infec-tions occur in China, Southeast Asia, and the Indian subcontinent; the highest per capita incidence occurs in sub-Saharan Africa.2 In the United States, the incidence of active tuberculosis has decreased steadily since 1992.3 However, the rate of decline has slowed in the past two years.4 Some states and urban centers still report increases in infections, and disparities in incidence and morbidity persist among certain high-risk groups