UK public health authorities are investigating three Salmonella Enteritidis clusters involving 474 confirmed cases and two deaths, with evidence pointing towards imported eggs used by foodservice businesses.
The UK Health Security Agency has widened its investigation after identifying increases in two additional clusters alongside the Salmonella Enteritidis t5.9411 outbreak reported earlier this month.
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Although the three clusters are genetically distinct, UKHSA said their genetic relatedness, together with epidemiological evidence and food-chain information, suggests they could all be associated with imported eggs.
The outbreaks are therefore being investigated in parallel by UKHSA, the Food Standards Agency and other public health partners.a
However, officials stressed that the exact sources have not yet been identified and that there is no evidence UK-produced eggs are affected.
Main cluster grows to 259 cases
As of 25 August, 259 confirmed cases and one death had been linked to the t5.9411 cluster.
This represents an increase of 52 cases from the 207 confirmed by UKHSA as of 13 August.
Samples connected to the cluster were collected between 11 August 2025 and 8 August 2026, although the majority of cases have been reported during 2026.
UKHSA said the latest investigation indicated a link with imported eggs, with cases associated with eating at small cafés, restaurants and takeaway businesses.
Two further clusters are also under investigation.
The t0.24068 cluster has been linked to 177 confirmed cases in England, with sample dates running from 27 May 2025 to 5 August 2026. No deaths have been reported in this cluster.
It was initially investigated during 2025 before the number of cases began increasing again from June 2026.
A third cluster, t5.9765, has been linked to 38 confirmed cases and one death in England. Sample dates range from 27 January to 29 July 2026.
Foodservice supply chains investigated
The FSA said epidemiological evidence and food-chain analysis had identified potential links to eggs imported from outside the UK and used mainly by foodservice and catering businesses.
No definitive source of contamination has yet been found and no product recalls or withdrawals have been announced.
Professor Ian Young, chief scientific adviser at the FSA, said investigations had identified links to imported eggs, but added: “There is no evidence that UK-produced eggs are affected.”
