You don’t have to be a pioneer on the Oregon Trail to catch the virus that causes dysentery.
Nowadays, the infection is spread more through sex and is progressing into something “almost incurable,” an expert said.
Shigella bacteria infect nearly half a million people in the United States each year, causing diarrhea with blood or mucus (characteristic of a dysentery infection), stomach pain, cramps, fever, and vomiting.
Scientists are learning more about why this worrying disease spreads so quickly and why it develops resistance to treatment.
Spread through sex
Shigella is a nasty disease that causes more than just uncomfortable shit. It can be life-threatening by dehydrating and depleting body fluids, including blood, causing bacterial and septic shock, neurological complications, as well as internal bleeding and infections.
The bacteria is spread through infected feces that enter the mouth due to poorly washed hands or ingesting contaminated food or water. A tiny amount – just 10 organisms – is enough to make you sick.
The population most likely to be infected is children under 5, who catch it at daycare and school from other children who are just beginning to learn how to stay clean. Travelers to places with lower health standards and people experiencing homelessness are also at higher risk.
But the population experiencing one of the fastest increases in Shigella infection is gay and bisexual men, as well as other men who have sex with men (GBMSM). Experts say shigella is “endemic” to these communities, meaning it is constant and regularly present.
A study in July showed that the spread of the disease through sex increased 15% faster year-on-year between 2015 and 2020 than through travel, food or outbreaks in day care centers.
New evidence suggests that sex may now even be the primary route of transmission, but it’s hard to tell when you don’t ask when patients present for medical care.
Experts say many people don’t realize that Shigella can be spread sexually – and that lack of awareness can fuel infections.
“Many men who have sex with men are unaware of the serious and growing risk posed by sexually transmitted Shigella,” said Kate Baker, a Cambridge geneticist and lead author of the July study.
Becoming a superbug
As Shigella spreads rapidly, it also becomes more difficult to manage. The CDC reports that drug-resistant infection strains have increased from 0% in 2011 to 8.5% in 2023.
“This disease has gone from relatively treatable with commercially available drugs to almost incurable over the past decade,” Baker said.
Why is this happening? Some experts believe that “bystander resistance” may be at play. This occurs when the wrong antibiotic is used for a pathogen, not only failing to kill the disease, but also accidentally giving the disease the opportunity to develop resistance to that antibiotic.
The CDC reports that most cases of drug-resistant shigella have affected adult men. Shigella strains transmitted through sex are serious. Research shows that those who contracted shigella through sex were hospitalized for four to five days on average.
“It’s not just a form of sexually transmitted diarrhea,” Baker told Science Alert.
“These are multiple, overlapping variants, all of which are rapidly becoming resistant to the drugs we use to treat them. It’s highly likely that if you contracted your Shigella sexually, you will need different treatment than someone who contracted it through travel.”
Treating and preventing shigella
Many cases of shigella go away on their own within a week, with the help of rest and fluids. But for serious infections, antibiotics can be used not only to shorten the illness, but also to reduce contagiousness.
This is becoming increasingly difficult as strains become more resistant to antibiotics. This is why the CDC calls for more attention and the development of prevention strategies.
They recommend:
- Wash your hands, genitals and anus with soap and water before and after sexual activity. This applies to everyone who has anal, oral, and vaginal sex, not just men who have sex with men.
- Wash sex toys with soap and water
- Use barriers like condoms and dental dams
The California Department of Public Health also adds simply: “do not have sex with anyone who has had diarrhea within the past two weeks.”
Gn Health
