Close to 500 people have become ill with salmonella in the United Kingdom, with authorities identifying two new clusters of the infection and recording two deaths. The UK Health Security Agency (UKHSA) reported that the total number of confirmed cases has risen to 474, an increase from 207 cases reported the previous week. These cases, some dating back a year, are linked by bacteria that are almost genetically identical, suggesting a common source.

Investigations are ongoing to pinpoint the exact cause of the outbreak. However, preliminary findings indicate a link to imported eggs. Experts suggest that many of those affected have fallen sick after eating out, rather than from consuming eggs cooked at home. Salmonella can be present in various food sources, including raw or undercooked poultry, meat, and eggs.

The current UK outbreak involves three specific genetic clusters: t5.9411, t0.24068, and t5.9765. Cluster t5.9411 is associated with 259 confirmed cases and one death, while cluster t5.9765 has 38 cases and one death. The remaining 177 cases are linked to cluster t0.24068. While most cases have occurred in recent weeks and months, the earliest recorded instance dates back to August 2025.

The majority of cases have been reported in England, with a significant number concentrated in London and the Yorkshire and Humber regions. Smaller numbers of cases have also been recorded in Scotland, Wales, and Northern Ireland. More than a third of those who have fallen ill in the UK, ranging in age from infants to 92-year-olds, have required hospital treatment.

Salmonella infections are also being observed in other European countries, including Austria, Belgium, Denmark, France, Germany, and the Netherlands. Notably, investigations in the Netherlands suggest a link with chicken meat rather than eggs in their outbreak.

To mitigate the risk of infection, health authorities advise thorough food preparation and cooking, as well as diligent hand washing before handling food and after using the bathroom. For consumers, eggs bearing the British Lion mark or produced under the Laid in Britain scheme are considered safe, as suppliers adhering to these standards undergo strict testing and vaccination protocols for their hens.

Professor Ian Young from the Food Standards Agency stated that efforts are continuing in collaboration with the UKHSA and other partners. He emphasized that while the precise origins are not yet identified, investigations so far point towards imported eggs, and there is currently no evidence suggesting that UK-produced eggs are affected.

The UKHSA has committed to continuing its follow-up of cases and investigating any further common sources that may emerge. Symptoms of salmonella typically include stomach cramps, diarrhoea, vomiting, and fever, usually appearing 12 to 72 hours after infection. While most individuals recover without medical intervention, older adults, babies, and those with weakened immune systems are at higher risk of severe illness.