An intestinal pathogen that causes diarrhea and vomiting is turning into a dangerous and difficult-to-treat sexually transmitted infection (STI).
In the United States, approximately 450,000 people acquire shigellosis each year, which can cause dysentery.
Historically, this highly contagious bug has spread mostly through contaminated food or water during travel and among young children in day care.
But since almost the turn of the century, Shigella The bacteria have also emerged as a sexually transmitted infection.
Shigella Infections can make anyone sick, but now they are ‘considered’local’In some communities of gay, bisexual and other men who have sex with men (GBMSM).
Many strains circulating in these communities have become resistant to multiple antibiotics.
Some are now superbugs, which are on the verge of becoming untreatable.
a fresh Analysis The US CDC found that out of about 17,000 Shigella Isolates, including variants that were extensively drug-resistant (XDR), increased from 2011 to 2023.
In 2011, isolates that were resistant to five commonly used antibiotics comprised 0 percent of samples. By 2023, they will make up 8.5 percent.
The vast majority of these drug-resistant variants had infected adult men, many of whom had not traveled internationally in recent months.
Molecular biologist Shangxin Yang says hospital staff at the University of California, Los Angeles (UCLA) are now seeing a case of widespread drug resistance. Shigella One month.
By comparison, in 2022, they saw only one case the entire year.
“It’s almost like this pathogen exploded in the community,” Yang told CIDRAP News at the University of Minnesota.
had sexually transmitted shigellosis first reported in 1974, but at that time it represented minority cases.
Now, emerging evidence suggests that sexual contact is a major route of transmission.
However, this information is difficult to verify, as patients and physicians may not realize it. Shigella Can be transmitted sexually, and sexual history may not be recorded.
More than a third of patients with extensively drug-resistant shigellosis were hospitalized, and nearly half of those with known HIV status had HIV, according to US CDC data.
“Overall, this is a very worrisome pattern of XDR Shigella strains that are being seen among vulnerable populations,” said CDC epidemiologist Naimah Logan. told CIDRAP News.
“This is by no means unique to the US, but is actually part of a broader global pattern.”
Kate Baker, a geneticist at the University of Cambridge, senior author of a recent study Lancet Infectious Diseaseshas identified a similar surge in the United Kingdom.
“Many men who have sex with men are unaware of the serious and increased risk of sexually transmitted infections Shigella,” Said Baker said in a July press release.
“Over the past decade or so, the disease has gone from being curable to being curable with the drugs available on the market.”
In March, the UK Health Protection Agency (UKHSA) caution While most cases Shigella resolution without treatment, more severe cases require treatment, and “available options are becoming limited.”
86 percent in 2025 Shigella soni samples and 94 percent shigella flexneri Samples tested by UKHSA researchers have shown resistance to antibiotics.
These are the two types most commonly spread through sexual contact among GBMSM in England.
in the east Research by Baker and OtherUp to one third of sexually transmitted patients Shigella Stayed hospitalized for an average of four to five days.
“It is not the only form of sexually transmitted diarrhea,” They say Baker.
“There are multiple overlapping variants emerging that are becoming increasingly resistant to the drugs we use to treat them. It’s highly likely that if you Shigella “Through sex, you need different treatment to someone who has contracted this infection while travelling.”
Why this is so, no one knows except Baker 2026 study indicates ‘Spectator resistance’ as a driver.
This means that an antibiotic designed for one pathogen may not be the correct drug or dosage for another existing pathogen, leading to resistance as a side effect.
In feedback In a recent study, Alicia Calvo-Villamanon, a researcher at the Gulbenkian Institute for Molecular Medicine in Lisbon, Portugal, pointed to an interesting connection.
“When UK national treatment guidelines stopped recommending the use of [azithromycin] For the treatment of gonorrhea infection,” he wrote, “the emergence of azithromycin resistance Shigella slowed down.”
This does not mean one is causing the other, but it does suggest that treating other STIs may be a risk factor for drug resistance. Shigella Infections that are not often investigated as STIs.
California Department of Public Health They say This is the best way to prevent Shigella Infection through sex means not having sex with someone who has had diarrhea in the last two weeks.
Using barriers during oral and anal sex is also recommended, as well as washing before and after sex.
To reduce transmission, anyone who suspects they may have an infection Shigella One should get tested and seek treatment if necessary.
“Physicians should ask patients with dysentery about sexual transmission and counsel accordingly,” Said Daniel Richardson, sexual health consultant at University Hospital Sussex, in July.
“They need to know that sexually transmitted Shigella Antimicrobial resistance is higher than other forms of the disease, and patients may need to be screened for other sexually transmitted diseases.”
This article was fact-checked by Rebecca Dyer and edited by Rebecca Dyer. Although we are proud of our process, we are only human. If you find any mistakes please let us know.