Health chiefs have warned of “high levels” of the sexually transmitted infection Shigella after 2,560 diagnoses were recorded last year in England, up from 2,052 in 2023 and 2,318 in 2024. Shigella is a gut infection spread through bacteria found in faeces. It can be passed on during sex, directly or through unwashed hands, with only a tiny amount of bacteria needed to cause infection.
The infection primarily affects gay, bisexual and other men who have sex with men, according to the UK Health Security Agency. Dr Katy Sinka, head of the STI section at UKHSA, said: “The rise in sexually transmitted Shigella cases is concerning, but the risk can be reduced through good hygiene during and after sex, and by using condoms — helping to protect both yourself and your partners.
“It is important that gay and bisexual men do not dismiss their symptoms and advice on self-care and preventing dehydration can be found on the NHS website by searching Dysentery.
“Those diagnosed with Shigella may also have been exposed to other sexually transmitted infections, including HIV, so a sexual health screen — at a clinic or by ordering tests online — is recommended.”
Symptoms of Shigella usually appear within one to four days and include diarrhoea (sometimes with blood), stomach cramps and fever.
The condition is often mistaken for food poisoning, according to the UKHSA.
The two most commonly sexually transmitted strains of Shigella are Shigella sonnei and Shigella flexneri.
While most cases will resolve without treatment, more severe cases do require treatment and the options available are becoming limited.
In 2025, 86% of Shigella sonnei samples and 94% of Shigella flexneri samples tested showed resistance to antibiotics.
More than half of Shigella sonnei cases were extensively drug-resistant, the UKHSA said.
People diagnosed with Shigella should avoid having sex for a week after their last symptoms.
They should also avoid swimming pools, jacuzzis, hot tubs, sharing towels and preparing food for other people.