Health experts are warning about a sharp rise in drug-resistant Shigella infections among gay and bisexual men in England, with London, Brighton and Manchester identified as key hotspots. While Shigella is not classified as a sexually transmitted infection (STI), it can spread during sexual activity involving contact with tiny amounts of faecal matter, and some strains are becoming increasingly resistant to antibiotics.
According to the UK Health Security Agency (UKHSA), laboratory diagnoses of sexually acquired Shigella rose sharply in 2025, with 2,560 cases recorded.
Cambridge Study Raises Alarm
A new University of Cambridge study, published in The Lancet Infectious Diseases, found that sexually transmitted variants of Shigella spread around 15% faster each year than strains linked to travel, contaminated food or childcare settings between 2015 and 2020.
Using genomic sequencing, researchers found these strains spread more than twice as quickly across the UK and developed antibiotic resistance at a much faster rate. By the end of the study period, more than 70% of sexually transmitted strains were resistant to at least one clinically important antibiotic, compared with around 40% of non-sexually transmitted strains.
Professor Kate Baker, senior author of the study, said sexually transmitted Shigella should be treated as a distinct public health threat.
'Many men who have sex with men are unaware of the serious and increasing risk posed by sexually transmitted Shigella,' she said, adding that the infection requires different prevention and treatment strategies because resistance is increasing rapidly.
It Is Not a 'Gay Disease'
Despite the current outbreak being concentrated within networks of gay, bisexual and other men who have sex with men (GBMSM), health experts stress that Shigella is not exclusive to one community.
The bacteria can also spread through contaminated food, water and poor hand hygiene. The increased transmission among GBMSM is linked to certain sexual practices involving oral-anal contact, not sexual orientation itself.
The Cambridge researchers found no evidence that the infection is unique to gay men, but identified sustained transmission within those sexual networks, particularly in major cities.
Reddit Users Push Back Against Stigma
The outbreak has prompted strong reactions on Reddit, where many users warned against turning the infection into another harmful stereotype.
'Great... one more thing to weaponise against us as a disgusting gay stereotype,' one Reddit user wrote.
Others reminded readers that Shigella is a bacterial infection rather than an STI and can be contracted through contaminated food or poor hygiene, not solely through sex.
Health experts agree that awareness should focus on reducing transmission, not stigmatising those most affected.
Symptoms and Prevention
Shigella causes diarrhoea, stomach cramps, fever and, in severe cases, bloody diarrhoea or dysentery. Symptoms usually appear within one to four days and many people recover within a week, although serious cases can require hospital treatment.
The UKHSA advises washing hands, genitals and sex toys thoroughly before and after sex, using condoms or dental dams during oral-anal contact, and avoiding sexual activity until after symptoms have completely resolved. Professor Baker also recommends waiting two weeks after recovery before resuming sex to reduce the risk of transmission.
While not every case is antibiotic-resistant, experts warn that sexually transmitted strains are becoming increasingly difficult to treat, making early testing, honest discussions with healthcare professionals about sexual history, and good hygiene more important than ever.
