Sexually transmitted diarrheal disease tied to Shigella is rising in the US, and CDC data show drug-resistant strains reached 8.5% in 2023. Kate Baker, the Cambridge geneticist who led the July study, said many men who have sex with men do not know the risk is increasing.
She said, “Many men who have sex with men are unaware of the serious and increasing risk posed by sexually transmitted Shigella.” Baker also said, “This disease has gone from being relatively treatable with off-the-shelf drugs to being close to untreatable over the course of the last decade or so.”
CDC data on Shigella
Shigella infects nearly half a million people in the US every year. It can cause diarrhea with blood or mucus, stomach pain, cramps, fever and vomiting, and as few as 10 organisms can make a person sick. The bacteria spread through infected poop that gets into the mouth through ill-washed hands or by swallowing tainted food or water.
The CDC reported drug-resistant Shigella strains at 0% in 2011 and 8.5% in 2023. The same CDC data said most drug-resistant cases affected adult men. Research also found people who contracted Shigella through sex were hospitalized for four to five days on average.
Kate Baker on transmission
Baker said the spread through sex grew 15% faster year-over-year between 2015 and 2020 than spread through travel, food or nursery outbreaks. Emerging evidence suggests sex may be the major route of transmission now, while clinicians do not always ask about sex when patients seek care.
That gap leaves the picture incomplete. The data show a rise in sexually transmitted spread and a sharp increase in resistance, but they do not answer how many current US cases are being transmitted through sex rather than other routes.
GBMSM risk in the US
Gay and bisexual men, and other men who have sex with men, are experiencing one of the fastest rises in Shigella infection. Baker said, “This isn't just one form of sexually transmissible diarrhea.”
For readers who may be affected, the practical issue is whether recent symptoms fit a Shigella infection and whether treatment could be harder than it was a decade ago. The rise in resistance means a shorter list of drugs can be expected to work, and the people most likely to be caught in that shift are adult men in the groups the CDC identified.
