One person has died and hundreds more have been taken ill following a significant salmonella outbreak linked to imported eggs.
The UK Health Security Agency has issued a national alert, saying evidence suggests many of those infected became unwell after eating at cafes and restaurants.
Health officials have confirmed 207 salmonella cases over the past year, involving patients aged from one to 90. However, experts cautioned that the true number is likely to be far higher, describing the confirmed cases as “just the tip of the iceberg” because many infections are never reported.
The Food Standards Agency said its investigation had found links to imported eggs, which are “mainly used by food service and catering establishments such as restaurants”.
The FSA stressed that there is currently no evidence UK-produced eggs are affected. It has nevertheless urged anyone handling eggs, eggshells or egg packaging to wash their hands thoroughly to help prevent the bacteria spreading.
Of the confirmed cases, 199 have been recorded in England, six in Scotland, one in Wales and one in Northern Ireland. More than a third of patients required hospital treatment, while two developed potentially life-threatening bloodstream infections, according to the UKHSA.
Salmonella infection is usually contracted by eating contaminated food, including poultry, meat, eggs, raw fruit and vegetables, and unpasteurised dairy products.
Common symptoms include fever and vomiting, and most people recover within a few days. In rare cases, however, salmonella can be fatal, with babies, pregnant women, older people and those with weakened immune systems at greatest risk.
The UKHSA has identified five unnamed food businesses which two or more of those affected reported attending in the week before getting symptoms.
More than a third of people affected in the outbreak were admitted to hospital
Jacquelyn McCormick, head of incidents at the FSA, said: ‘While investigations continue, our advice around eating eggs remains the same.
‘Eggs which are thoroughly cooked and handled hygienically should not present a food safety risk. Infants, young children, pregnant people and older adults should only eat runny or raw eggs if they have a British Lion mark or are produced under the Laid in Britain egg assurance scheme.
‘This advice does not apply to those who are severely immunocompromised and require medically supervised diets.’
London has seen the highest number of cases, with 47, followed by Yorkshire and Humber (38). The UKHSA said the outbreak appeared to be connected to a previous spate of cases last year, which was also linked to imported eggs. Dr Damien Tully, from the Medical Research Council, said: ‘This is a sizeable outbreak, but the number of confirmed cases is likely to be just the tip of the iceberg.
‘Many salmonella infections cause relatively short-lived gastrointestinal illness and people may recover without ever being tested, meaning the true number of infections associated with an outbreak can be considerably higher than the number identified through laboratory surveillance.’
Commercial hens which produce eggs sold in UK supermarkets are vaccinated against the most common strains of salmonella, making any outbreak unlikely to start in Britain.
Despite this, salmonella cases have been on the rise in the UK. Last year, there were 10,406 recorded cases – a decade high.
Experts say the majority of these are thought to be linked to imported produce. In particular, the UK has faced multiple salmonella outbreaks originating from poultry products from Poland.
Salmonella is a bacterial infection often described simply as ‘food poisoning’.
The bacteria lives in the gut of farm animals and is shed through their stool. Most people become infected by consuming food or water that has been contaminated by the faeces. It is most common in raw meat, poultry, seafood and eggs, because the cooking process kills off the bugs.
Faeces may get on to raw meat and poultry during the butchering process, while seafood may be contaminated if harvested from contaminated water.
