A person has died and hundreds of people have been affected by a food poisoning outbreak, health officials have said.

The UK Health Security Agency (UKHSA) said the salmonella outbreak ‘may be linked to eggs imported from outside of the UK’.

There has been one death associated with the outbreak, UKHSA said.

The Food Standards Agency (FSA) said that there is ‘no evidence that UK-produced eggs are affected’.

It said that investigations had identified links to imported eggs ‘mainly used by food service and catering establishments such as restaurants or cafes, as a potential source’.

Salmonella generally causes a self-limiting gastroenteritis, with symptoms including stomach cramps, diarrhoea, vomiting or fever.

More than a third of people affected (38%) in the outbreak were admitted to hospital, with two people developing potentially life-threatening blood stream infections.

UKHSA said between August 11 last year and August 1 this year, 207 cases have been confirmed – 199 in England, six in Scotland, one in Wales and one in Northern Ireland.

One expert said that the figure reported ‘is likely to be just the tip of the iceberg’ as many cases will be unreported.

The regions in England with the highest number of cases are London, where 47 cases were confirmed, and Yorkshire and Humber (38).

People affected include babies and people as old as 90, according to the UKHSA.

Hannah Charles, lead epidemiologist for gastrointestinal infections at UKHSA, said: ‘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.

‘Salmonellosis is often caused by eating or handling contaminated food and can be spread rarely from person-to-person.

‘Salmonella generally causes a mild illness, although vulnerable groups with weakened immune systems may experience more severe illness.

‘Symptoms of a salmonella infection include diarrhoea, stomach cramps and sometimes vomiting and fever. Anyone who is concerned about symptoms should contact their GP or out of hours service in the first instance.

‘There are simple steps to prevent the spread of salmonella: wash your hands thoroughly after using the bathroom and before preparing and handling food, cook food thoroughly, and if you have any symptoms, avoid handling food for others where possible.’

Jacquelyn McCormick, head of incidents at the Food Standards Agency, said: ‘We are working closely with the UK Health Security Agency and other partners to investigate an outbreak of Salmonella Enteritidis.

‘The exact cause has not yet been identified, however investigations so far have identified links to eggs imported from outside the UK, mainly used by food service and catering establishments such as restaurants or cafes, as a potential source.

‘There is no evidence that UK-produced eggs are affected.

‘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.

‘We continue to advise people who are handling eggs, eggshells or egg packaging to always wash their hands thoroughly with warm water and soap and dry them properly afterwards.’

Dr Damien Tully, associate professor at the Medical Research Council/Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine Uganda Research Unit, 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.’

Dr Tully added: ‘For most healthy people, salmonella causes an unpleasant but self-limiting illness, although it can occasionally cause serious disease, particularly in young children, older adults and people with weakened immune systems.

‘Good food hygiene remains important: wash your hands before preparing or eating food, avoid cross-contamination in the kitchen, and make sure foods such as eggs, poultry and meat are cooked thoroughly.’

Nick Allen, chief executive of the British Egg Industry Council, said: ‘It is deeply concerning that imported eggs are once again under scrutiny in connection with a serious salmonella outbreak.

‘We have repeatedly raised concerns about the risks associated with imported eggs and egg products with Government.

‘British Lion egg producers have invested heavily in world-leading food safety controls, including mandatory salmonella vaccination, traceability and independent auditing – yet increasing volumes of imports produced under less stringent regulations continue to arrive.

‘There must be a level playing field. Imported eggs and egg products entering the UK should meet standards equivalent to those expected of British producers if we are serious about protecting British consumers.

‘Food businesses and caterers should not have to compromise on food safety when sourcing eggs.’

What is salmonella?

Salmonella is a bacterium that thrives in the intestine of animals, including chickens, birds and cows.

Livestock don’t seem sick when carrying the bacteria, so it easily winds up in meat, produce or is spread to crop fields and around food processing plants, where the bacteria can contaminate packaged produce.

This is why salmonella is often found in food such as raw or under-cooked poultry or red meat.

The bacteria can also wriggle into eggs as they are forming inside a sickened hen and later ggeton egg shells when hens lay eggs or if the eggs touch infected droppings.

Symptoms of salmonella

The infection caused by the bacteria is called salmonellosis.

Symptoms include nausea, tummy pain, diarrhoea and vomiting. People usually start to feel sick six hours to six days after being exposed.

In severe cases, salmonella can contaminate the human bloodstream and cause infection and inflammation of the arteries and arthritis.

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