"As long as you breathe, you are at risk anywhere in the world," says physician Lucicia Ditiu.
The risk she's referring to is catching tuberculosis. While it may seem like a disease from the past, this airborne illness kills more people than any other infectious disease worldwide, roughly 1.2 million a year. That number could increase dramatically because of the Trump administration's cuts to foreign assistance, according to a new study co-authored by Ditiu.
As many as 10 million additional people could get TB, and 2.2 million could die by 2030 in high-burden countries under the worst-case funding scenario over the next five years, researchers report in the journal PLOS Global Public Health. Even if funding is fully restored in a matter of months — a scenario that seems unlikely — the researchers estimate half a million more cases and nearly 100,000 more deaths by the end of the decade.
"The impact of these cuts will be concentrated in countries with the least capacity to reallocate funding to close the gap created by cuts to health aid," says Nicolas Menzies, an associate professor of global health at Harvard University who wasn't involved in the study. "I think the methods are pretty solid," he says of the findings, though with any effort to project out illness and death, they come with a hefty dose of uncertainty. In particular, it's hard to know precisely how much funding cuts translate to service disruptions, especially since countries will have varying responses to the cuts.
An important takeaway from the projection, he says, is that the longer it takes to close those funding gaps, the greater the impact.
The potential toll of these cuts is so stark, in part, because the U.S. supports a majority of TB programs in countries with a high burden. In 2024, the U.S. accounted for more than 55% of total external foreign aid for TB control, with much of the commitment — roughly $400 million — coming from USAID. All that money helped fund the full gamut of TB care: screening for cases, detection and diagnosis; distributing meds; and supporting patients as they undergo what can be a grueling months-long treatment.
In Bangladesh, for instance, USAID has invested over $100 million in the country's TB program over the past decade. The funds have helped reduce annual TB deaths by 36% since 2015, to roughly 44,000 in 2023. But roughly 20% of people with TB in the country still fall through the cracks and don't get diagnosed.
In January, Tasmieh Selim, a public health professional at the nonprofit BRAC, was just starting work on a USAID-funded project to reach those people. They were a week into U.S.-funded efforts to expand the country's diagnostic network with more portable x-ray machines and advanced tests when they got a stop work order. Months later, the program is still stalled.
"It hurt a lot," she said. "There is still a need for those activities in the field, but we are not able to perform [them] because of lack of budget."
Numbers are already changing
The abrupt aid cuts are just beginning to show up in the data for some countries.
"We've observed a drop in the number of people diagnosed and treated, especially in [parts of] Africa and Asia," says Ditiu, study co-author and executive director of the Stop TB Partnership, a non-profit. Some countries have preliminarily seen a 10 to 15 percent drop so far, she says. "All of this will have an even bigger impact, because people untreated die."
Precisely how many could die is difficult to say, in part because it's unclear exactly how much TB funding was cut and whether national governments have found alternative sources of funding.
In a statement to NPR, the State Department, which houses what's left of USAID, said "currently 20 countries — including 10 countries with bilateral TB programs — are receiving funds from American taxpayers to implement lifesaving TB interventions such as TB case finding, treatment, prevention, and procurement of TB medicines and commodities."
They did not provide specifics on how much funding. "The State Department will continue its mission to encourage other donors, including governments and the private sector, to develop sustainable solutions for those most in need," the statement said.
Ditiu says that it's difficult to know exactly how much U.S. funding remains, but that many countries are grappling with serious cuts. Even with those uncertainties, Ditiu says estimating how cuts could stoke an increase in TB cases and deaths is crucial for helping countries plan.
How the researchers worked
To get those estimates, Ditiu and her colleagues combined what's known about TB's epidemiology — how it spreads, how it kills, how treatment and prevention can mitigate that — with available data on how U.S. funding for TB programs. That allowed them to estimate the impact of U.S. funding cuts for 26 high burden countries.
The researchers modeled three different scenarios. In the least bad, the researchers assumed the funding cuts lasted just 90 days and would then be fully restored, with countries back to baseline within three months. In the moderate scenario, it takes countries a year to get their TB services back to baseline. And in the worst-case scenario, countries never get fully back on track, and their TB control programs operate at permanent deficits.
"In the worst case scenario we found that more than 10 million new cases of TB could emerge between now and 2030, and about 2.2 million deaths," says Carel Pretorius, study co-author and an infectious disease modeler at Avenir Health, a global health consulting firm.
Even a rapid recovery would lead to about 100,000 additional deaths by 2030, the team found. That's largely because of cases that would go undiagnosed as efforts by health care workers to find people living with TB wither.
That kind of outreach is critical, says Ditiu. "If you wait for people to come to you, it will be too late," says Ditiu — there's a longer period when they can spread the disease and later-stage disease is more challenging to treat, as the bacteria further degrade the lungs and other organs.
Although TB is not as infective as an airborne virus like COVID-19, "we estimate one sick person untreated can infect around 15 to 20 people a year," she says.
Additionally, if people in the midst of the months-long drug regimen lose access to the drugs, the drugs, bacteria can evolve resistance. "Treating drug-resistant TB is very expensive, it can go as high as $400,000 per individual," says Ditiu.
Currently, Ditiu suspects that countries are on track for something around the moderate scenario, where 268,000 additional people could die by 2030.
Ditiu hopes that outlining the scale of potential suffering will galvanize counties and donors to push for the lower range of study's projections. Such efforts benefit the hardest hit countries, but also wealthier countries that have forgotten the threat of TB, says Ditiu. In the interconnected world of 2025, she says, "It's a risk for everyone."
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