Drug-resistant tuberculosis is becoming more common.
The antibiotics that only 80 years ago turned TB from a voracious killer of an estimated 1 billion people to a treatable disease just don’t work anymore.
But researchers are looking for ways to fight that.
One of the people who does that for a living is in San Antonio.
"It's an armored bacteria. It knows exactly how humans respond to it. It laughs at it. It's growing in the places it shouldn't be growing," said Dr. Larry Schlesinger, president and CEO of Texas Biomedical Research Institute. "And as a result, that battlefield is pretty intense. And the bugs are winning,"
The National Institutes of Health selected Texas Biomed to be a premier training center for TB researchers of the future.
"We need better drugs," Schlesinger said. "We need host- directed therapy. We need better approaches because this is a very human-adapted organism that has been around for centuries."
That's not how scientists typically think about tuberculosis in 2023. The most recent potentially deadly infectious disease that can viciously attack the lungs was COVID-19.
"So COVID became the number one infectious disease cause of death for a while during the pandemic, and it actually rose above tuberculosis," he said.
From 2020 to 2022, confirmed cases of TB rose more than 15%. The good news is the disease is still less prevalent than it was before the pandemic. The bad news is the rising case numbers come after a nearly three-decade decline.
Tuberculosis remains by far the number one infectious disease killer of humans worldwide. More than 10 million people get ill with TB each year, and more than one and a half million people die of tuberculosis each year.
Researchers estimate that more than 1 billion people have died of tuberculosis, far more than any other infectious disease.
There is a vaccine against tuberculosis, but it isn't very effective and is not widely used in the U.S.
So the treatment for TB, since 1944, has been antibiotics.
"We have a limited number of drugs and they're toxic. And even with those drugs over years of therapy, people still can die of tuberculosis. So resistance has a major impact on outcome," he said. And that resistance has been slowly increasing, not a huge amount, but it's been increasing enough to continue to be a concern."
Resistance in TB is categorized as drug-resistant, multi-drug-resistant, or extensively drug-resistant, and Schlesinger said scientists are racing to find new treatments.
"I's absolutely a race. The problem is that humans evolve very slowly. Our immune systems evolve very slowly over generations and generations. Microbes evolve much more quickly, and they can mutate and change readily all the time. It is definitely a race. And typically, when a new strain of microbe, particularly one that's resistant, emerges, it gets the upper hand," he said. "And we're usually not prepared, and it takes time for us to develop programs to react to those new strains."
When Schlesinger imagines the future of tuberculosis treatment, he sees what’s known as host-directed therapy.
"So this is akin to cancer immunotherapy. We're looking for ways to bolster the immune system to work in conjunction with those antibiotics to fight the bacteria," he said. "And those host-directed therapies have the promise of being as effective for drug resistant bacteria as drug susceptible bacteria."
This is still preclinical, but it's one example of how one can work with the immune system to override the bacterial suppression systems in this case.
"Our goal over the next five to 10 years is to produce outstanding researchers that go out and do great things in the world, whether they're at universities, the World Health Organization, the CDC, individuals who are very experienced and can help us get a handle on TB," Schlesinger said. "This won't be handled in my lifetime, but I'm hopeful, based on the training we provide, that the next generation will find those cures and we'll be able to develop better tools for diagnosis and certainly less toxic treatment, shorter-course therapy and better vaccines."
Schlesinger said the hope is this work will better prepare the U.S. if and when the next infectious disease crisis emerges.
