The UK Health Security Agency (UKHSA) reports a sustained and pronounced rise in sexually transmitted Shigellosis infections across England, the largest country within the United Kingdom. Epidemiological data show that this outbreak predominantly affects men who have sex with men (MSM).
In 2025, England recorded 2,560 cases of sexually transmitted Shigellosis in adult men who had not recently traveled abroad, representing about a 25 percent increase from 2023. More than half of the diagnoses (54 percent) occurred in the Greater London area.
Critical development in antibiotic resistance
The real challenge for the health system lies in the bacteria’s genetic changes. The share of bacterial samples showing resistance to common antibiotics has reached a critical level: 86 percent of tested Shigella sonnei samples were resistant, while 94 percent of Shigella flexneri samples were resistant.
This severely limits treatment options for severe cases. For people with weakened immune systems, such as those with HIV infection that is not optimally controlled, the risk of serious clinical complications rises.
How Shigella spreads
Shigellosis requires only a very small number of bacteria (about 10 to 100 organisms) to cause infection. Transmission is fecal-oral, which can occur during sexual activity — particularly through rimming or direct hand-to-mouth contact after sex. Typical symptoms include watery or bloody diarrhea, fever, nausea, and painful abdominal cramps.
Because of international mobility and the interconnectedness of queer communities, these resistant bacterial strains circulate globally. Since the 1970s, Shigella epidemics among gay and bisexual men in developed nations have recurred. In recent years, similar clusters and rising case numbers have also been observed in major German cities like Berlin. The Pre-exposure Prophylaxis (PrEP) that has grown popular in recent years among MSM protects against HIV, but not against other sexually transmitted infections.
Communities and organizations focused on sexual health recommend enhanced hygiene measures during and after sex. These include thorough handwashing and the use of condoms. In addition, particularly sexually active gay men who experience persistent gastrointestinal symptoms should seek medical care and inform clinicians of the sexual risk so that appropriate lab testing can be ordered.
