True number of salmonella infections could be ‘around 2,000’, top expert warns – amid ongoing UK outbreak linked to imported eggs

The number of people infected in the ongoing salmonella outbreak may be more than four times greater than official figures suggest, an expert has warned.

Officials from the UK Health Security Agency (UKHSA) yesterday said the total number of confirmed cases had reached 528 across three separate infection ‘clusters’.

Two people have also died as a result of the outbreak, which officials suspect has been caused by imported eggs.

But Paul Wigley, a professor in animal microbial ecosystems at University of Bristol, says the true number of infections could be significantly higher.

‘It could be 1,500 to 2,000 or so,’ he told the Daily Mail. ‘I wouldn’t be surprised if it’s up around the 2,000 mark.

‘In fact, I wouldn’t be shocked if it’s much higher than that. But around 1,500 to 2,000 cases is what I would be expecting.’

There are around 10,000 lab-confirmed cases of salmonella in the UK every year.

However, Food Standards Agency (FSA) chiefs believe the true number may be around 32,000.

Prof Wigley said this is because hundreds of patients may have milder forms of the disease without severe symptoms such as prolonged diarrhoea.

They are unlikely to seek medical help, so may not be analysed and later confirmed as an official case.

While salmonella – caused by bacteria entering the body – can be deadly, some people with stronger immune systems can shake it off within around a week.

‘Most people are just going to say, I’m not that ill, I’m not well, but I’ll ride it out,’ Prof Wigley explained.

He did warn, however, that even these people may experience ‘uncomfortable and nasty’ symptoms.

While milder signs include stomach cramps, prolonged bouts of diarrhoea can lead to severe dehydration.

Other more dangerous reactions include blood poisoning, organ failure and death.

Salmonella is typically caught by eating contaminated food such as poultry, meat, eggs, raw fruit and vegetables and unpasteurised dairy products. 

Those most at risk of fatal complications include infants, pregnant women, the elderly and those with weakened immune systems.

More than a third of patients in the three outbreaks have required hospital treatment.

Professor Wigley’s comments come weeks after Dr Damien Tully, from the Medical Research Council, said the number of confirmed cases is ‘likely to be just the tip of the iceberg’.  

He added: ‘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.’

Officials have so-far said the infections have been linked to eating out at ‘small cafes, restaurants and takeaway businesses’.

Food safety chiefs have urged Britons to avoid ‘raw or lightly cooked egg’ products such as mousses, mayonnaise or hollandaise sauce.

Vulnerable groups – including over-65s, pregnant women and under-fives – are also advised to avoid runny eggs when eating out.

Officials say there is no evidence that eggs produced in the UK pose any threat.

Hannah Charles, lead epidemiologist at UKHSA, said yesterday: ‘We continue to work closely with the Food Standards Agency and other public health partners to investigate these Salmonella clusters.

‘Our investigation to date indicates a link to imported eggs, however this investigation remains ongoing. We will continue to follow up cases and investigate any further common sources if they come to light.’

She also stressed that the overall risk to the public ‘remains low’.