The U.S. is slowly but steadily closing in on tuberculosis.
For the first time since the government started tracking the disease in the 1950s, the number of annual TB cases has dropped below 10,000, the Centers for Disease Control and Prevention said Thursday in the Morbidity and Mortality Weekly Report.
TB cases declined 6 percent last year compared to 2011, the report said, making it the 20th consecutive year cases of the disease has fallen. More than 40 percent of counties haven't had a single TB case in the past three years.
During the late 1980s, TB made a worrisome comeback in the U.S. One reason was the burgeoning AIDS epidemic, which left many people susceptible to TB. An overall deterioration of services for TB patients exacerbated the problem.
The CDC and local health departments beefed up money and resources for TB. Since 2000, cases of the disease have fallen nearly 40 percent.
Now in the U.S., TB is most prevalent among Asians, who have a 25-times higher rate of catching it than whites. Over the past year, TB has declined the fastest for Hispanics and blacks, the report finds. But still 60 percent of cases are seen in foreign-born people.
Nearly half of all TB cases occur in just four states: California, Texas, New York and Florida. Just last month, Los Angeles health workers called in the CDC to help them stop an ongoing outbreak among homeless people.
Such outbreaks demonstrate one of the major challenges of wiping the disease completely: TB hits hardest in vulnerable populations, such as the homeless, that don't have access to good health care.
The second challenge, noted by the report, is the troubling rise of drug-resistant TB around the world. The CDC recorded 127 cases of drug-resistant TB in 2011, and 64 cases of a particular dangerous type of TB, known as extensively drug-resistant tuberculosis, or XDR-TB from 1993 through 2012.
Just last November, immigration officials quarantined a Nepalese man, after he tried to enter Texas illegally with XDR-TB. Public health officials expect more of them.
"There's no way to ever isolate the U.S. from an airborne disease," Dr. Edward Zuroweste, of the nonprofit group Migrants Clinicians Network, told Shots in March. "The world is becoming much smaller and people travel a lot."