An antibiotic-resistant superbug responsible for bad diarrhea and fever symptoms has been on the rise in the US since at least 2023, according to explosive new data detailed by the CDC.
Shigella infections were once easily zapped by antibiotics like azithromycin and ciprofloxacin, but the CDC reported that 8.5% of all Shigella bacteria samples sent to labs across the country in 2023 were "extensively drug-resistant," or XDR. They no longer responded to standard treatments.
What's worse: There is no FDA-approved alternative for patients who catch the bug.
For most Shigella hosts, the infection isn't deadly. With or without antibiotics, it tends to resolve after about a week of intense diarrhea, fever and stomach pain.
But it can be life-threatening for immunocompromised patients and children under 5. A Shigella infection puts them at higher risk of developing dysentery in low- and middle-income countries, per a recent Lancet study arguing for widespread access to a Shigella vaccine.
While a vaccine isn't available, there are a handful of candidates in clinical trials.
Nationwide, an estimated 450,000 Americans come down with some form of Shigella each year.
It's a nationally notifiable disease like dengue or hepatitis, so doctors are required to report cases to their health departments. Researchers and health officials who track the data and test bacteria samples found that XDR cases have been climbing over the last 15 years.
In 2011, none of the tested Shigella samples were drug-resistant. By 2023, 8.5% of samples were.
While Shigella can be picked up during travels -- through contaminated food and water -- the majority of analyzed cases were from patients with no recent travel history. And while no deaths were reported, a third of the cases resulted in hospitalization.
Sexual contact, especially anal sex, can also transmit the germs, potentially helping to explain why recent XDR Shigella outbreaks have been linked to adult queer men.
Even with the aid of antibiotics, which usually only cut symptoms short by a couple of days, the only way through a Shigella infection is to ride it out. The CDC recommends drinking plenty of fluids to replenish the body and prevent dehydration and avoiding Imodium or Lomotil if the diarrhea is bloody.
Researchers are increasingly concerned about broad resistance to antibiotics.
Well over a million people die each year from drug-resistant bacteria, and by 2050, the World Health Organization estimates that number could be 10 times higher.
As troubling as the bacteria are, it's equally frightening to see how they evolved into their drug-resistant state.
Scientists believe it's possible that the genes they developed might migrate to other gut bacteria, shielding them against antibiotics, too.
It's for this and other reasons that the CDC has labeled XDR Shigella a "public health threat" in need of immediate prevention tactics like increased susceptibility testing and prompt reporting of cases presented to doctors throughout the country.
For now, without a surefire Shigella treatment or vaccine on hand, the best hope for curbing the outbreak is to develop a stronger antibiotic that can overpower the bug.