World TB Day is recognized each year on March 24, which commemorates the date in 1882 when Dr. Robert Koch announced his discovery of Mycobacterium tuberculosis, the bacillus that causes tuberculosis (TB). World TB Day is an opportunity to raise awareness about TB and support worldwide TB prevention and control efforts. The U.S. theme for World TB Day, “Unite to End TB,” highlights how much more needs to be done to eliminate TB in the United States.

After 2 decades of annual declines, TB incidence in the United States has leveled at approximately 3.0 new cases per 100,000 persons (1,2). The determinants of this leveling in TB incidence are not yet clear; further evaluation of available data is required to understand the causes of this trend.

CDC is committed to eliminating TB in the United States. Staying on the path toward TB elimination will require more intensive efforts, both in the United States and globally. These efforts will not only focus on strengthening existing systems for interrupting TB transmission, but also on increasing testing and treatment of persons with latent TB infection. Additional information about World TB Day and CDC’s TB elimination activities is available on CDC’s website (http://www.cdc.gov/tb/worldtbday).