UK Salmonella Outbreak Nears 500 Cases, Two New Clusters Identified

Nearly 500 people in the United Kingdom have become ill with salmonella linked to imported eggs, UK authorities say, after identifying two new clusters of the infection. The UK Health Security Agency (UKHSA) reported 207 cases last week, a figure that has since risen to 259. Adding the two newly recognised clusters brings the total number of confirmed cases to 474, with two deaths recorded. Some of the illnesses date back a year, but genetic testing shows the bacteria are almost identical, pointing to a common food source.

The outbreak involves three near‑identical genetic clusters, designated t5.9411, t0.24068 and t5.9765. Cluster t5.9411 accounts for 259 confirmed cases and one death; t5.9765 has 38 cases and one death; and t0.24068 is linked to 177 cases. Most of the cases have occurred in recent weeks and months, with investigations tracing back to August 2025. England has reported the majority of cases, especially in London and Yorkshire and Humber, while smaller numbers have appeared in Scotland, Wales and Northern Ireland.

Investigations are still ongoing, but early evidence suggests that the infections are most likely contracted after eating out rather than cooking eggs at home. Similar salmonella cases have been reported in other European countries, including Austria (2 cases), Belgium (15), Denmark (1), France (4), Germany (6) and the Netherlands (106). In the Netherlands, investigations point to a link with chicken meat rather than eggs. Salmonella can be found in a range of foods, including raw or under‑cooked poultry, meat and eggs.

More than one‑third of those infected in the UK, including babies and people as old as 92, have required hospital care. While most people recover without treatment, older adults, infants and those with weakened immune systems are at higher risk of severe disease. Symptoms such as stomach cramps, diarrhoea, vomiting and fever usually develop 12 to 72 hours after exposure. Anyone who is concerned is advised to contact a general practitioner or out‑of‑hours service first, according to the UKHSA.

The UKHSA has confirmed that the outbreak is linked to imported eggs and that there is no evidence of an issue with UK‑produced eggs. “We will continue to follow up cases and investigate any further common sources if they come to light,” the agency said.

Prof Ian Young, a senior epidemiologist at the Food Standards Agency, said the agency was working closely with the UKHSA and other partners. “The exact causes of these outbreaks have not yet been identified, but investigations so far have identified links to imported eggs,” he said. “There is no evidence that UK‑produced eggs are affected.”

The Food Standards Agency has reminded the public that it is safe to buy and eat eggs that carry the British Lion mark or are produced under the Laid in Britain egg assurance scheme. Suppliers of British Lion‑mark eggs must adhere to a strict code that includes regular testing and vaccination of hens against salmonella.

To reduce the risk of infection, experts advise cooking food thoroughly, washing hands after using the bathroom and before handling food, and avoiding raw or under‑cooked eggs and poultry. The outbreak remains under active investigation, with authorities continuing to monitor new cases and trace potential sources.