Experts have warned that sexually transmitted shigellosis, a bacterial infection that causes severe diarrhoea, is becoming a "growing and urgent public health threat" as it grows increasingly resistant to treatment. Researchers say the disease is becoming "virtually untreatable", with cases in England having risen by a quarter since 2023, raising concern among health officials in the UK.

Shigellosis is a gut infection caused by shigella bacteria and is traditionally spread through contaminated food or surfaces, but scientists say it is increasingly being transmitted sexually, particularly between gay and bisexual men, as the bacteria can be passed on through contact with faeces during anal sex. Symptoms include intense diarrhoea, often with blood in the stool, stomach cramps, fever and vomiting. The infection kills more than 200,000 people worldwide each year through complications such as dehydration, intestinal perforation and malnutrition, and experts warn the antibiotics normally used against it are becoming less effective.