IMPORTED eggs are being investigated as a possible source of a national Salmonella Enteritidis outbreak involving 207 confirmed cases and one death, although officials have stressed that the origin of the contamination has not been confirmed.
The UK Health Security Agency said egg consumption remained the strongest signal identified during its investigation.
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Testing showed that the cases were caused by closely related strains of Salmonella, suggesting a common source, and that the strain was similar to one involved in a 2025 outbreak linked to imported eggs. However, eggs have not been formally confirmed as the source of the current outbreak, and no link has been identified to UK-produced eggs or poultry.
Of the confirmed cases, 199 were in England, six in Scotland, one in Wales and one in Northern Ireland. London had recorded 47 cases and Yorkshire and the Humber 38.
Most of those affected experienced self-limiting gastrointestinal illness, but 38% of people for whom information was available were admitted to hospital because of their symptoms. Two people developed bloodstream infections and one death has been associated with the outbreak.
Egg supply chains examined
UKHSA has completed detailed questionnaires with 114 cases. Of these, 95 – equivalent to 83% – reported eating food prepared outside the home during the week before their symptoms began.
Investigators identified five food businesses that had been visited by two or more independent cases. These businesses were connected to 24 cases in total, with 11 reporting that they had eaten dishes containing eggs.
Food-chain investigations found that the businesses received eggs from several different sources, including egg importers. Possible cross-contamination risks were also identified at two of the premises, meaning the evidence does not yet establish that eggs were the source of the infections.
Hannah Charles, lead epidemiologist for gastrointestinal infections at UKHSA, told the BBC: “We’re working with Food Standards Agency and other public health agencies to investigate a salmonella outbreak that may be linked to eggs imported from outside of the UK.”
UKHSA’s formal report is more cautious, stating that extensive epidemiological and food-chain investigations remain under way to determine the source and origin of the contamination.
It added: “At this time there is no identified link to UK-produced eggs or poultry.”
Link to previous imported-egg outbreak
Whole-genome sequencing has shown that the infections form a closely related cluster, indicating a common source of contamination.
The outbreak strain is also genetically related to a separate Salmonella Enteritidis outbreak recorded in 2025, which was linked to imported eggs. UKHSA said it was working with the Animal and Plant Health Agency, the Food Standards Agency and public health bodies in the devolved administrations to assess any potential risks associated with imported eggs.
Dr Kathleen O’Reilly, associate professor at the London School of Hygiene & Tropical Medicine, said eating eggs outside the home, potentially including internationally produced eggs, appeared to be a possible common factor. She cautioned that the information was not definitive and that other sources could emerge as the investigation continued.
Dr Damien Tully, also an associate professor at LSHTM, said the genetic relationship with the previous imported-egg outbreak provided investigators with an important lead. Establishing the source would nevertheless require the genomic findings to be combined with information about where cases had eaten and product tracing through the food supply chain.
