An old bacterial foe has been making itself very cozy in Kansas. Local health officials reported this month that the state is in the midst of a large outbreak of tuberculosis—reportedly now the largest outbreak of the disease ever documented in the United States.
Ashley Goss, a deputy secretary at the Kansas Department of Health and Environment (KDHE), gave an update on the state’s TB outbreak to the Senate Public Health and Welfare Committee last week. Dozens of active and latent TB cases have been linked to the outbreak dating back to last year. And the danger has not yet passed.
“The current KCK Metro TB outbreak is the largest documented outbreak in U.S. history, presently,” Jill Bronaugh, a spokesperson for KDHE, told local media outlet The Topeka Capital-Journal Friday. “This is mainly due to the rapid number of cases in the short amount of time. This outbreak is still ongoing, which means that there could be more cases.”
TB is caused by Mycobacterium tuberculosis. It spreads between people through the air and typically affects the lungs, though it can invade elsewhere. Acute cases of TB usually result in respiratory symptoms like chest pains, chills, and coughing up blood. But the infection can also become latent, not causing illness until years later when the immune system is weakened for another reason. People with HIV are especially vulnerable to TB, since they’re much more likely to develop an acute, life-threatening case.
This is the largest recorded TB outbreak in U.S. history, but given the disease’s long history, it’s highly likely that Americans dealt with larger outbreaks in the past. Bronaugh notes that the Centers for Disease Control and Prevention’s tracking of TB only extends back to the 1950s, by which time the disease had started to wane significantly in the U.S., thanks to improved public health and later the availability of effective antibiotics. Prior to these developments, TB has often been a common threat to Americans. Even in 1945, just as these new antibiotics were arriving, there were an estimated 115,000 new cases of TB in the U.S., along with 63,000 deaths.
That said, TB has remained a major killer elsewhere. A report from the World Health Organization last fall, for instance, found that TB had once again become the world’s leading cause of death from a single infectious disease in 2023 (reclaiming the top spot from covid), with roughly 1.25 million TB-related deaths estimated that year. And though cases and deaths of TB have stayed low in the U.S., it’s been gaining ground here lately as well. In 2023, there were 9,633 reported cases of TB in the U.S.—the third straight year of rising cases and enough to surpass pre-pandemic levels.
According to the KDHE, there have been 67 active cases of TB tied to the outbreak in the Kansas City, Kansas, metro area since 2024, along with 79 latent cases. Most of these cases have been reported in Wyandotte County, though a handful have been reported in nearby Johnson county as well.
One reason why TB outbreaks can be difficult to manage is that it can take up to nine months of antibiotic treatment to ensure that someone is cured of it. Drug-resistant strains of TB can further complicate treatment, though these still only account for a small minority of cases. According to the KDHE, however, it takes much less time to ensure that someone with TB is no longer contagious to others with ongoing treatment (as little as 10 days). And since the summer, officials have helped significantly reduce the number of active TB cases in the area (now down to 32, according to Goss). So while this outbreak is alarming, it’s hopefully on its way to being fully contained.
“We still have a couple of fairly large employers that are involved that we’re working with on this,” Goss told the state Senate committee. “So we do expect to find more, but we’re hoping the more that we find is latent TB not active, so that their lives are not disrupted and having to stay home from work. Because it is highly contagious.”
Globally, experts have blamed the pressures of the pandemic for the recent uptick in TB, particularly in weakening screening and prevention programs for the disease. At this point, however, there appears to be no clear explanation for the outsized number of cases in this local outbreak. And given the ongoing pause in communication from federal health agencies like the CDC, it’s unknown whether the CDC will even weigh in publicly anytime soon.