Recent study tracks the rapid spread of drug-resistant Shigella across England

A nationwide genomic epidemiology study involving a Kingston University researcher has found that sexually transmitted Shigella sonnei is spreading faster, over greater geographical distances and with higher transmission intensity in England than non-sexually transmitted strains.

The study, published in The Lancet Infectious Diseases and led by the University of Cambridge and the UK Health Security Agency (UKHSA), provides probably the most detailed account yet of how this happens
Shigella – traditionally referred to as a food- and water-borne enteric infection – has evolved right into a rapidly circulating, drug-resistant sexually transmitted infection (STI) that primarily affects the sexual networks of gays, bisexuals and other men who’ve sex with men.

Shigella is mostly present in stool and is transmitted through contaminated food. They may cause severe diarrhea, fever, and stomach cramps.

UKHSA figures show there have been greater than 2,500 cases of sexually transmitted Shigella in England in 2025, up from just over 2,000 in 2023.

The study analyzed 3,514 Shigella samples from people over the age of 16 within the UK between 2004 and 2020. Over a period of two and a half years, the sexually transmitted Shigella strains were found to spread a mean distance of 117 km, in comparison with 46 km for non-sexually transmitted strains.

The study also found that 70 percent of sexually transmitted Shigella strains were immune to at the least one clinically relevant antibiotic, in comparison with 40 percent of non-sexually transmitted cases and 49 percent of cases by which they were infected while traveling.

Previously, public health authorities relied on basic hygiene measures corresponding to handwashing and avoiding contaminated food or water to contain outbreaks.

Researchers, including Dr. Nonetheless, Lewis Mason, senior lecturer in biological sciences on the University of Kingston, emphasize that these standard infection prevention measures are largely ineffective against sexual transmission of Shigellavia through direct or indirect oral-anal contact during sex.

To curb the spread of drug-resistant shigellosis, researchers suggest there may be an urgent have to develop alternative interventions, corresponding to effective vaccines, microbiological clearance pathways and tailored treatment guidelines, in collaboration with patient communities.

While discussing the outcomes of the study, Dr. Mason, she underscored the necessity to higher manage antimicrobial responses to pathogens at the general public health level. “”