“Concerning” rise in cases of extensively antibiotic-resistant Shigella sonnei infections, mainly in gay, bisexual, and other men who have sex with men

The UK Health Security Agency (UKHSA) has announced there has been a “concerning” rise in cases of extensively antibiotic-resistant Shigella sonnei infections, mainly in gay, bisexual, and other men who have sex with men (GBMSM).

Since the beginning of 2023, the number of extensively-antibiotic resistant Shigella cases has increased by 53%. Much of this increase has been driven by a cluster of extensively-antibiotic resistant Shigella sonnei, of which there have been 97 cases in 2023 (up to and including November), compared to just four cases last year.

According to UKHSA, the strain is difficult to treat because it does not respond to the antibiotics typically used to treat Shigella. Cases have been diagnosed in all regions of England – but cases are concentrated in London (45), the North West (21) and South East (12).

In January 2022, there was similar rise in cases of extensively antibiotic-resistant Shigella sonnei infections caused by another outbreak strain.

Cases of Shigella have been rising since the easing of COVID-19 restrictions in July 2021, with annual cases now higher than the average before the pandemic. The month with the highest number of reported Shigella diagnoses prior to the COVID-19 pandemic was 392 in September 2019, which increased to 485 in September 2023 – representing a 24% increase.

Shigella is a gut infection that causes diarrhoea (sometimes mixed with blood), stomach cramps and fever. It is caused by bacteria found in faeces.

It can be passed on through the faecal-oral route during sex, either directly or via unwashed hands and only a tiny amount of bacteria can spread the infection. Symptoms are typically seen between one and four days after exposure and are commonly mistaken for food poisoning.

Dr Gauri Godbole, Consultant Medical Microbiologist at UKHSA, said: “This is a concerning rise in cases of this antibiotic resistant strain, meaning treatment can be very difficult. One of the best ways to protect yourself and your partners is to practice good hygiene after sex. Avoid oral sex immediately after anal sex, and change condoms between anal or oral sex and wash your hands with soap after sexual contact.

“It’s important that GBMSM do not dismiss their symptoms and speak to their GP or sexual health clinic, mentioning Shigella, if they are unwell. GBMSM with Shigella may have been exposed to other STIs including HIV, so a sexual health screen at a clinic or ordering tests online is recommended.”

Shigella is very infectious and while symptoms can be unpleasant, in most cases they will subside within a week, but some individuals need hospitalisation and require intravenous antibiotic treatment. Effective antibiotic treatments are limited for this extremely resistant strain.

Antibiotic treatment is recommended in cases with severe symptoms, those requiring hospital admission, those with prolonged diarrhoea (beyond seven days) or in those who have underlying immunodeficiency.

UKHSA advises that if you have been diagnosed with Shigella, give yourself time to recover. Keep hydrated and get lots of rest. Don’t have sex until seven days after your last symptom and avoid spas, swimming, jacuzzis, hot tubs and sharing towels as well as preparing food for other people until a week after symptoms stop.

You can find out more information about Shigella and get advice on other topics at Sexwise or by calling the free National Sexual Health Helpline at 0300 123 7123.