The Curious Hotel

Sexually transmitted cases of bacterial gut infection shigella are spreading rapidly, a study has found - with experts warning of a "distinct public health threat".

Shigella cases transmitted through sexual contact spread more than twice as fast in terms of distance as other strains of the infection and are becoming increasingly resistant to treatment, according to a study led by the University of Cambridge and the UK Health Security Agency (UKHSA).

Shigella, the bacteria behind dysentery, is most commonly found in faeces and contracted through contaminated food and causes diarrhoea, stomach cramps and fever.

Certain strains - specifically shigella sonnei and shigella flexneri - can be spread through sexual contact, primarily among gay and bisexual men.

UKHSA figures show that there were 2,560 cases of sexually transmitted shigella in England in 2025, up from 2,052 in 2023.

The study, published in the Lancet Infectious Diseases journal, analysed 3,514 samples of shigella from people over the age of 16 in the UK between 2004 and 2020.

Over a two-and-a-half-year period, the sexually transmitted shigella strains were found to spread an average distance of 117km, compared with 46km for non-sexually transmitted strains.