Health authorities are investigating a series of salmonella outbreaks across the United Kingdom that have caused two deaths and sickened close to 500 people. Early evidence points to imported eggs used in restaurants, cafés and takeaways as the likely source, according to officials at the UK Health Security Agency.

The outbreaks span three separate but related clusters of Salmonella Enteritidis, a common cause of food poisoning. Data published by UKHSA shows the largest cluster, designated t5.9411, has recorded 259 confirmed cases and one death since it was first identified in August 2025. A second cluster, t5.9765, has caused 38 cases and one death since January 2026. A third, t0.24068, has been linked to 177 cases since May 2025, though no deaths have been reported in that strand of the investigation. Case numbers across all three clusters have risen noticeably since June 2026, prompting closer scrutiny from health officials.

Genetic sequencing has established that the three clusters belong to a wider family of Salmonella Enteritidis, sharing enough similarities to suggest a common upstream source even though the outbreaks have been tracked separately. Investigators believe the common thread lies in imported eggs supplied to hospitality and catering businesses rather than in eggs sold through retail outlets. There is currently no evidence that eggs produced in the UK are implicated, and officials have been careful to distinguish the domestic supply chain from the imported products under investigation.

The Food Standards Agency has said the overall risk to the public remains low. Most people who contract salmonella experience symptoms that are unpleasant but short-lived, including stomach cramps, vomiting and fever, usually resolving within a week without medical treatment. The picture is different for certain groups, however. Pregnant women, young children, the elderly and people with weakened immune systems face a higher risk of severe illness, including sepsis in extreme cases, and are being advised to take particular care.

For those groups, the FSA's guidance centres on how eggs are prepared when eating out. Dishes containing raw or lightly cooked egg, such as fresh mayonnaise, mousse or hollandaise sauce, should be avoided at restaurants and cafés unless the establishment can confirm the eggs used are British sourced. Eggs carrying the British Lion mark or the Laid in Britain certification remain considered safe to eat raw or lightly cooked by most people, reflecting the traceability and food safety standards applied to the domestic supply chain. The agency has stressed that this advice applies specifically to catering settings, where the origin of eggs used in a dish is not always visible to the customer, rather than to eggs bought and prepared at home.

UKHSA and the FSA are working in parallel to trace the exact origin of the imported eggs linked to the outbreaks. Officials from both agencies have said the investigation remains active and that further updates will be issued as more information becomes available. A spokesperson for UKHSA said the agencies were continuing to work closely with international partners and food businesses to identify the source and prevent further cases.

Whole genome sequencing of salmonella samples taken from hospitals across the UK plays a central role in this work. The technique allows scientists to compare the genetic fingerprint of bacteria found in different patients, linking cases that might otherwise appear unrelated and helping investigators trace outbreaks back to a common source with greater precision than older laboratory methods allowed. It was this sequencing work that first revealed the connection between the three clusters now under investigation.

Officials have not named specific restaurants, suppliers or countries of origin while the investigation continues, and have urged food businesses to review their egg sourcing and to follow standard food hygiene practices, including thorough cooking and proper storage. The public has been advised to wash hands and surfaces after handling raw eggs and to seek medical attention if symptoms of salmonella infection persist or worsen, particularly among those in higher risk groups.

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