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), UKHSA has announced.
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 4 cases last year.
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 a 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 1 and 4 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 gay, bisexual, and other men who have sex with men (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 sexually transmitted infections (STIs) including HIV, so a sexual health screen at a clinic or ordering tests online is recommended.
Shigella is very infectious. Although 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 7 days) or in those who have underlying immunodeficiency.
