Sexually transmitted Shigella is spreading faster among men who have sex with men, and drug-resistant strains climbed to 8.5% in 2023 after starting at 0% in 2011. That combination is turning an infection that once responded to ordinary treatment into one that is much harder to manage.
Kate Baker said many men who have sex with men do not realize how serious the risk has become. She also said the disease has moved from being relatively treatable with off-the-shelf drugs to being close to untreatable over the last decade, a warning that helps explain why the phrase Sexually Transmitted Diarrhea is drawing attention now.
Shigella infects nearly half a million people in the US every year, but the rise that matters today is happening in a specific pattern of spread. A July study found that transmission through sex grew 15% faster year-over-year between 2015 and 2020 than spread through travel, food or nursery outbreaks, and emerging evidence suggests sex may now be the major route. That shift matters because as few as 10 organisms can make someone sick.
The illness usually brings diarrhea with blood or mucus, stomach pain, cramps, fever and vomiting. It can also become life-threatening by dehydrating the body and triggering shock, neurological complications, internal bleeding and infection. Children under 5, travelers to places with lower sanitation standards and people experiencing homelessness are also at higher risk, but the fastest rise is among gay and bisexual men and other men who have sex with men.
That is where the public-health problem gets harder to contain. Shigella spreads when infected poop gets into the mouth through unwashed hands or contaminated food or water, and Baker’s point is that many people still do not connect that route with sex. The CDC says most drug-resistant cases have affected adult men, and research shows people infected through sex were hospitalized for four to five days on average.
The question now is how quickly the resistance problem keeps moving. Drug-resistant Shigella was at 0% in 2011 and had reached 8.5% by 2023, which means more infections are entering the narrow space where routine drugs no longer work well. If the trend continues, the gap between how Shigella spreads and how it is treated will keep widening.
