In early 2023, a rare but deadly form of meningitis began appearing across the United States, especially among patients who had undergone cosmetic surgery at two clinics in Matamoros, Mexico, a city across the border from Texas.

The U.S. Centers for Disease Control and Prevention issued a notice to alert doctors in May, and they began finding dozens of confirmed and probable cases across the U.S., especially in Texas, as well as in Mexico. Patients who had been to the two clinics were notified that they may have been exposed to the fungus.

A bewildering outbreak

There were three bewildering things about this outbreak: first, the meningitis was fungal rather than bacterial or viral, which is already unusual – but it's even more unusual for a fungal meningitis to appear in young people who aren't immune-compromised.

Second, it was drug-resistant, so none of the drugs on the market could combat it – which meant patients would die without effective treatments.

And third, the fungus was attacking the brain stem with unusual fervor. It was eating away at the blood vessels of the brain stem, breaking and clotting the blood vessels until patients suffered strokes, aneurysms, brain hemorrhages, brain swelling and eventually death.

In a study published this month in the New England Journal of Medicine, researchers describe 13 cases of the fungal meningitis, nine of which were fatal, at three Texas hospitals. Three of those patients remain on an experimental medication.

The patients tended to be young women, mostly in their 20s and 30s, who had received epidurals for surgeries like tummy tucks and Brazilian butt lifts between Jan. 1 and May 13, 2023, at the two clinics.

The epidural medications seem to have been tainted with the fungus, which entered the spinal fluid and worked its way up to the brain stem. In the weeks after their surgeries, the patients began reporting headaches and low-grade fevers that soon worsened into horrific medical complications. In total, 12 patients with probable or confirmed cases died in this outbreak..

While there are always risks with epidurals, infections like these are vanishingly rare when proper sanitary procedures and regulations are followed. The investigation in Mexico is still ongoing, but experts believe there was likely a breach of these procedures. At the time, there was a shortage of morphine, a common ingredient in epidural anesthesia, and it's possible the morphine was procured or stored in "less than ideal" conditions, said Dr. Luis Ostrosky, division director of infectious diseases at UTHealth Houston and one of the study authors.

The need for due diligence

Medical tourism, where patients seek cheaper care in other countries, can carry rare but deadly risks like these, Ostrosky said.

"There are great, great clinics abroad with very well-trained physicians and very serious hospitals that are even certified by the accrediting bodies here in the United States — so you just need to do a lot of due diligence," Ostrosky said.

He encouraged potential patients to check a clinic's certifications and even look at photos of the facility online. "Visit the place — if it looks kind of dirty or janky, don't go there."

Outbreaks like this one are "relatively rare," said Dr. David Boulware, professor of medicine at the University of Minnesota Medical School with a special focus on meningitis, who was not affiliated with this study. But the risks of medical tourism are "not zero."

"You can certainly go abroad and you can get less expensive medical care. But it's sort of buyer beware," he said.

The outlook for meningitis patients

Cases of meningitis, which is inflammation of the brain and spinal cord, have greatly diminished over the past few decades, said Boulware. "It's something that's not in the consciousness, I think, as much as 20 or 30 years ago, [but] it can be a particularly deadly disease."

However, this type of fungal meningitis in healthy young people is "a really uncommon thing," he said.

There was an outbreak of fungal meningitis in another city in Mexico a few months earlier, in Nov. 2022, with 80 cases and 41 deaths linked to epidurals.

And there was an outbreak in the U.S. in 2012 among patients who received steroid injections in their back. The supervising pharmacist at the compounding pharmacy who mixed that custom-made medication was later sentenced to prison for illegal practices.

In the cases recorded in 2023, after doctors and specialists gained experience treating the patients and began using a medication not yet on the market, patients began improving.

"That's when we kind of changed the course of the illness and we started to have some survivors," Ostrosky said. "People that were on the verge of dying, we were starting to rescue them."

Most of the surviving patients are still on the medication, which was given through a "compassionate use" program given the dire circumstances. They're still being closely monitored – and they're not yet out of the woods.

"It is kind of like knowing that you may have a time bomb in yourself. So it's very emotionally draining for them," Ostrosky said.

Restoring faith in public health

The fast action taken by doctors and public health officials helped save lives, both because they were actively looking for cases and because they were able to warn future travelers about the potential risks of epidurals in Mexico.

"It speaks to the role of public health, because they actually conquered it fairly quickly," Boulware said. "It probably prevented a lot of excess mortality, and kind of shut things down."

Work like this could help restore battered trust in health experts after years of a bruising pandemic, he said.

"The CDC certainly got bashed a lot during COVID. But this is one of the other things that they do that ultimately protects patients, because this could have gone on for months or could have gone on forever, if no one was really looking and investigating."

Melody Schreiber is a freelance journalist and the editor of What We Didn't Expect: Personal Stories About Premature Birth.