Investigators say imported eggs could be associated with the outbreaks
Salmonella cases linked to an investigation into imported eggs have risen to 650 in England, up by more than 100 since mid-September.
UK health officials are investigating three outbreaks of Salmonella Enteritidis, with epidemiological, genetic and food-exposure evidence suggesting they could be associated with imported eggs.
However, investigators have not confirmed imported eggs as the definitive source, and there remains no identified link to UK-produced eggs or poultry.
The latest UK Health Security Agency (UKHSA) figures show 413 cases in the largest cluster, 194 in a second and 43 in a third, bringing the combined total to 650.
That is 101 more cases than the 549 infections reported by FarmingUK in mid-September.
The largest cluster has risen by 22 cases in the latest weekly update, while the other two increased by five and one respectively.
Cases have been recorded across most regions of England and involve people ranging from infants to those in their 90s.
Two deaths have been associated with the three outbreaks, while hospital admissions have also been recorded across all three clusters.
UKHSA said hospitalisation information is only available for a proportion of confirmed cases.
In the largest cluster, 65 of 247 people for whom hospitalisation information was available had been admitted to hospital.
In the second cluster, 25 of 54 cases with available information had been hospitalised, while nine admissions were recorded among 22 cases in the third outbreak.
The Food Standards Agency (FSA) has identified a potential connection with eggs supplied to a number of UK hospitality and catering businesses as part of its tracing investigation.
The regulator has stressed that no link has been identified with UK-produced eggs or poultry.
Investigations involving UKHSA, the FSA, public health bodies and the Animal and Plant Health Agency are continuing.
The largest cluster also forms part of a wider European outbreak, with related cases reported in Austria, Belgium, Denmark, France, Germany and the Netherlands.
UKHSA has warned that the true number of salmonella infections is likely to be higher than confirmed surveillance figures, as people with milder symptoms may not seek medical treatment.
UK laying flocks are subject to salmonella control measures including vaccination, biosecurity and monitoring, with assurance schemes such as British Lion and Laid in Britain incorporating additional requirements.
Existing food safety advice remains in place.
Older adults, pregnant women, young children and people with weakened immune systems can eat raw or lightly cooked hen eggs where they carry the British Lion mark or are produced under the Laid in Britain assurance scheme.
When eating out, where customers may not know whether eggs are covered by one of those schemes, vulnerable people are advised to ensure eggs are thoroughly cooked and to avoid foods containing raw or lightly cooked egg.
Salmonella infection can cause diarrhoea, stomach cramps, vomiting and fever, with most infections resolving without treatment.
More serious illness can occur in vulnerable groups, including young children, older people, pregnant women and those with weakened immune systems.
UKHSA, the FSA and animal-health authorities are continuing to investigate the source of the outbreaks, with updated case numbers expected as surveillance continues.