Fewer U.S. residents were diagnosed with tuberculosis last year than the year before — down from 9,094 to 9,029, the fewest new cases ever reported, according to the Centers for Disease Control and Prevention. Still, the goal of eliminating TB in the United States is unlikely to become a reality in the 21st century, the CDC says. It attributes that in large part to data showing that the incidence of TB — defined as the number of cases per 100,000 people — is now declining at a slower pace, down 1.3 percent from 2017 to 2018, compared with a 4.7 percent annual decline from 2010 to 2014. Last year, the incidences of TB was found to be highest in Alaska and lowest in Wyoming. The CDC said that “as has been the case for over two decades,” four states — California, Florida, New York and Texas — accounted for about half of the reported cases of TB in 2018.

Tuberculosis is caused by bacteria that mainly attack the lungs, although other parts of the body also can be affected. The bacteria is spread through tiny droplets in the air, when an infected person coughs, sneezes or even just talks or laughs and someone else breathes in the bacteria. But even if someone gets infected, most of the time their immune system is strong enough to keep them from getting sick. Instead, they have what is called latent TB, meaning they have TB germs in their bodies but they are not sick and are not contagious. They could still develop active TB, even years later, if their immune system weakens. Most cases of TB can be treated and usually cured with medication, although some strains are drug-resistant. The disease can be fatal if untreated, however.

— Linda Searing