Sign up for the Slatest to get the most insightful analysis, criticism, and advice out there, delivered to your inbox daily.
Tuberculosis has been crawling its way back into the spotlight. In 2020, after a three-decade decline, TB cases in the U.S. began climbing again. Last year, that number was at its highest since 2011. There has been a TB outbreak in Kansas since January 2024, with over 100 people infected and two deaths. Recent data show that Europe saw a 10 percent rise in childhood infections in 2023, with more than 7,500 cases. What with World Tuberculosis Day this week, and the release of John Green’s new book Everything Is Tuberculosis last week, TB, which is often thought of as an old-timey disease, might seem to suddenly be a concern once again.
In reality, though, tuberculosis never went away. It regularly kills over a million people a year and infects millions more. It is literally the world’s deadliest infectious disease—yes, you read that right. It was bumped out of first place by COVID-19 for a while, but it returned to the top last year.
We don’t hear much about TB in the U.S. because it’s largely under control here, but it’s a huge threat in other regions, particularly Southeast Asia and Africa. There are treatments for TB. And yet, the federal government’s recent cuts to foreign aid mean that many people across the world will no longer be able to access treatment (on top of all the people who already lacked access to treatment). “We can cure virtually everyone with tuberculosis,” says William Schaffner, a professor of infectious diseases at Vanderbilt University Medical Center. “We have the capacity to do that.” As Slate’s Tony Ho Tran wrote eloquently in a piece about Green’s new book: “It’s a decision to let people die.”
That decision also increases the risk for Americans, most of whom have long been lucky enough to not have to think about TB. Let’s talk about it.
So why are cases rising in the U.S. right now?
Any time there’s turbulence in the world, the risk of transmission increases. That’s true of most diseases, but especially for TB, which requires long courses of treatment to work. Whether due to armed conflicts, refugee migration, or a global pandemic, “if populations are in turmoil, public health breaks down,” says Schaffner. “And tuberculosis control programs come to a screeching halt.” That’s what happened in 2020, when COVID brought the world, and TB control programs, to a stop. When those initiatives stall, infected individuals can’t receive their treatment, and they can’t be monitored and supported while receiving their treatment. That leads to more transmission, which means more infections—which increases risk even in places where the disease has been under control.
I’m realizing I don’t even know what tuberculosis is .
Fair enough! It shows up in movies and books as old-fashioned and romantic—think poets wasting away by the seaside of “consumption” (TB’s historical nickname). The wasting-away part is true: “For the most part, TB is a smoldering disease,” says Schaffner. It kills slowly. But it’s definitely not romantic.
Tuberculosis is caused by bacteria that, after infecting a person, tend to hibernate in the body. It can stay there for five, 10, 20 years, without causing any symptoms. This is known as latent infection, and it’s not contagious.
Eventually, though, the bacteria wake up, and that’s when active infection starts. At that point, the person with the infection is now contagious. The bacteria start eating away at the lungs, destroying tissue. From there, it can move to other parts of the body. Symptoms—prolonged cough, chest pain, weakness, fever—may start off mild. Depending on the person’s age and health, they can suffer from active infection for more than a year, losing weight due to lack of appetite and extreme abdominal pain, until their lungs collapse or fill with fluid—or a few other terrible possibilities.
But there are treatments available, right?
Yes. “TB is curable and preventable,” according to the World Health Organization’s website. However, treatment isn’t a straightforward one-and-done kind of thing. It involves six months of a multidrug regimen; using just one drug can lead to the bacteria’s becoming resistant such that they simply do not respond to that drug. In some cases, if treatment is implemented incorrectly, a person’s bacteria can become resistant to multiple drugs, which then makes it very difficult to treat. Multidrug-resistant TB is considered a pretty serious public health issue.
Crucially, you don’t want something happening in the middle of TB treatment that disrupts a patient’s access to drugs. The Trump administration’s funding cuts to the U.S. Agency for International Development, which among many other things supports TB treatment programs, are just that kind of disruption.
Yikes. What about preventing TB in the first place? Is there a vaccine?
There is one, but it’s not very effective for adults or adolescents. For babies and small children in countries where TB is common, it can help protect against death and more severe illness.
Finding a new, better TB vaccine is one of the holy grails of vaccinology, says Schaffner, along with better flu and COVID vaccines and an HIV vaccine: “These are at the top of the list of every vaccinologist’s Christmas list.”
Can we treat latent TB, then? Get ahead of things, instead of waiting for the infection to become active?
We can! And that’s the ideal situation: Find everyone with latent TB and treat them before they become contagious and experience symptoms. “That’s actually part of the plan of every state’s TB program,” says Schaffner. “And we need to do more of that.” You can test for TB with an easy skin test; there’s also a newer blood-test option. The good news is that if you do have latent TB, you don’t have to wait until it becomes active to receive treatment (which is still a regimen of multiple drugs over several months).
Related From Slate
[
Anna Gibbs
Uh … Am I Protected Against Measles? It Might Depend On When You Were Born.
Read More](https://slate.com/technology/2025/03/measles-outbreak-vaccine-booster-titers.html)
OK, I’m ready to get tested! Point me to the nearest TB testing stand.
If you’re near the outbreak in Kansas, you may be contacted by public health authorities to get tested. In those cases, “please cooperate with the public health authorities, because it’s to your own benefit,” says Schaffner. But in general, we don’t do mass TB testing in the U.S. because there’s no real need. Despite being deadly, TB is not contagious in the way that measles or COVID is—TB typically requires prolonged exposure. Certain populations are at higher risk of TB, Schaffner says, including people in low-income areas, people who have been in prison, people with HIV infection, or people raised in countries where TB is more common. Screening is more important in those communities. Other populations, like health care workers, are regularly tested for TB.
But if you don’t fall into any of those categories, it’s very, very, very unlikely that you’re harboring TB bacteria.
But with TB rates rising in parts of the world …
Right. People in the U.S. are extremely fortunate to not have to think about tuberculosis on the regular. As the richest country in the world, we have a responsibility to help those who are less advantaged. So we should care about the rising cases for humanitarian reasons. But TB in other parts of the world does also concern the U.S. directly. “Germs don’t need a passport,” says Schaffner. “Whatever’s over there can be over here in 24 hours.” This is true of any infectious disease, and something we saw very clearly with COVID-19. Again, TB is not at all like COVID—and the primary reason to worry about TB is because of the destruction it causes globally, not because of the risk it poses to you personally. But the more TB spreads, the higher your chances of being near an outbreak.
Undoubtedly, the cuts to USAID funding—which, in addition to funding prevention, testing, and treatment services, has been the world’s third-largest TB research funder—will lead to more illness and death. It might not be immediately apparent in the data, says Schaffner, because TB is a relatively slow-moving disease. But many lives are already being affected. As WHO Director General Tedros Adhanom Ghebreyesus told Reuters: “The fact that TB still kills and sickens so many people is an outrage, when we have the tools to prevent it, detect it and treat it.”