What’s Behind the Recent Rise in Tuberculosis Cases?
A disease that was almost eradicated last century has been making headlines in 2025. With cases increasing over the past few years and recent outbreaks in Kansas and Florida, among other states, tuberculosis (TB) has attracted new attention from health officials and the general public.
“Not every state has seen this increase. We think there could be a couple of things going on,” said infectious disease specialist Michelle Haas, MD, who has been monitoring the changes in TB cases closely.
Given TB’s historic impact on public health, new outbreaks in the U.S. are worth taking seriously. Infections with TB bacteria can cause severe symptoms, including weight loss, night sweats and occasionally chest pain. If left untreated, TB can be fatal.
So why have cases been increasing, and will TB become the large-scale deadly threat it once was? Dr. Haas helped to shed some light on the current situation and the future of TB.
COVID’s Role
While the recent increase in cases have been alarming, according to Dr. Haas, the main reason behind these higher numbers is our recovery from COVID 19. “We are still recovering from the decrease in identified TB cases related to COVID,” said Dr. Haas. “There was a fairly sharp dip in the number of people diagnosed with TB globally in 2020.”
Dr. Haas explained that many people weren’t coming in for care due to the pandemic. “Additionally, the movement of resources to help deal with COVID led to a lack of resources for TB,” said Dr. Haas. “When people finally were being diagnosed with TB, you could tell that their TB was more advanced.”
The masking practices adopted during the pandemic also could have contributed to lowering the spread of TB in other countries, according to Dr. Haas. “Surgical masks are effective at stopping droplets from the mouth, which is one of the main ways TB is transmitted.” Dr. Haas explained further that in the U.S., where there is almost no community transmission of TB, masking probably had very little impact.
Likelihood of Widespread TB Infection
Even though increases in TB cases are worth monitoring, Dr. Haas noted that physicians and researchers aren’t seeing evidence of broader transmission. “In these cases where there’s a surge in numbers, such as the recent outbreak in Kansas, it's mostly delays in diagnosis,” said Dr. Haas. There's really no community transmission of tuberculosis in the U.S. Part of that is because you have to have a certain number of people in a community with TB before you start to see widespread transmission. You also have to spend a lot of time with someone who has active tuberculosis. When I say a lot of time, I mean usually about eight hours. So it's very different from COVID where you could get exposed in 15 minutes.”
Even though TB infections are unlikely to return to the rates seen by Americans during the late 1800s, Dr. Haas stressed that having public health institutions was crucial to keeping TB at bay. “There's always the chance that there can be an unraveling of public health,” said Dr. Haas. “We've been in an okay place with TB, but if we lose the ability to do contact tracing, that could change. It’s Important to find everyone with TB and connect them with care. If that doesn’t happen, we would start to see an increase in TB cases here in the U.S.”