Releasing the most recent domestic and global data on tuberculosis incidence in this week’s Morbidity and Mortality Weekly Report, the U.S. Centers for Disease Control and Prevention emphasized that while rates of new cases continue to drop, they are not declining swiftly enough to reach important and achievable goals.
Those goals include ones agreed to by international health leaders and policy makers to end the most devastating public health impacts of the disease, and to eliminate the disease in the U.S. — a goal defined as one case or less per million people — by the end of this century.
While U.S. TB incidence has dropped, on average, by 1.6 percent annually in the last four years (from 2014 to 2018) that decline represents a leveling off from the previous, 2010 to 2014, yearly 4.7 percent declines in new cases. Last year’s 9,029 reported cases of tuberculosis in the United States is 0.7 percent fewer than the year before, showing a 1.3 percent decrease in incidence from 2017’s rate, and bringing the lowest numbers of real numbers and rates ever reported. That rate of progress however, falls far short of what would be needed to eliminate the disease in the U.S. by the start of the next century, the authors note.
To reach that goal, efforts would need to be greatly increased to screen and provide preventive treatment to many more of the roughly four percent of people living in the U.S. with latent tuberculosis infection. Without preventive treatment from 5 to 10 percent of those infected will develop active disease. Those at highest risk include people born outside the U.S. particularly in countries where rates of the disease are high. The rate of disease among non-U.S. born residents of this country is 14 times that of those born here. Other risks include lack of secure housing — 4.1 percent of cases were reported in people who had been homeless in the year leading up to their diagnosis. Correctional settings are home to 3.3 percent of people reported with TB in the last year. Time spent in a long-term care facility, where 1.6 percent of new patients had been, poses another risk. And of all new patients whose HIV status was known, 5.3 were living with the virus as well.
Worldwide, tuberculosis remains the leading infectious disease killer, and the leading cause of death among people living with HIV. The 10 million new cases reported in 2017, the most recent year for which data has been counted, represents a 1.8 percent drop from 2016 numbers. Of those cases 5.6 cases were resistant to more than one first-line treatment. The 1.57 million deaths caused by TB also represents progress — a decline of 3.9 percent from the year before. Southeast Asia and Africa were home to nearly 70 percent of all reported new cases. HIV was a significant driver of incidence in African countries with 27 percent of new cases among people living with the virus. Inadequate nutrition in the midst of poverty, appears to be a driver in Asian countries. An estimated quarter of the world population lives with latent infection. Accelerated and much wider access to the newest medicines bedaquiline and delamanid will be essential to controlling the spread of the disease, as well as curtailing its toll, the authors note.
The edition of MMWR was released ahead of World TB Day. For more on the March 24 commemoration, including stories from survivors, visit the CDC site here.