US tuberculosis cases increase for the first time in 23 years

© Mario Anzuoni
For the first time in nearly a quarter-century, the United States saw an uptick in tuberculosis last year, according to the Centers for Disease Control and Prevention (CDC).

The CDC report, released Thursday, found that 29 states and the District of Columbia reported more cases of the airborne lung disease in 2015 than in 2014.

"After two decades of declining incidence, progress toward TB elimination in the United States appears to have stalled," the CDC report said.

While the increase is notable because it’s the reversals of a 23-year downward trend, the overall change is small. There were 9,563 cases in 2015, only 142 more than in 2014. Officials aren’t sure why progress towards reducing the disease’s prevalence has ground to a halt, and said that the data needs further evaluation.

Caused by a type of bacteria that attacks the lungs, tuberculosis remains the world’s number-one infectious killer. It can be spread when an infected person coughs or sneezes, and can be fatal if left untreated.

The uptick in cases of TB in the United States comes at a time when the global fight against the disease has run into obstacles, thanks to the proliferation of drug-resistant bacterial strains. About two-thirds of new cases in the US each year are diagnosed in foreign-born immigrants, most of whom are from Asia.