Thousands of fresh supermarket chickens have been infected with a potentially fatal food poisoning bug, data shows.
Up to one in 25 raw broiler chickens sold in Britain are classified as highly contaminated with campylobacter – the biggest cause of food poisoning.
The Food Standards Agency (FSA) instructs supermarkets to measure levels of the bacteria and sets strict targets for the proportion of poultry meat that can be affected.
No one violated the agency’s limit. But in the worst performing supermarkets – Asda, Lidl and Waitrose – up to four percent of raw chickens on shelves were contaminated.
Campylobacter usually causes diarrhea, nausea and vomiting, which gets better on its own within a week. But in severe cases it can kill vulnerable groups, including young children, the elderly and people with suppressed immune systems.
The Food Standards Agency (FSA) instructs supermarkets to measure levels of the bacteria and sets strict targets for the proportion of poultry meat that can be affected. No one violated the agency’s limit. But in the worst performing supermarkets – Asda, Lidl and Waitrose – up to four percent of raw chickens on shelves were contaminated.
Supermarkets must report data on the prevalence of campylobacter in their poultry products every three months so that the FSA can monitor food quality.
They share the proportion of their raw broiler chickens that contain more than 1,000 colony-forming units per gram (CFU/g) of campylobacter. At this level, chickens are considered highly contaminated and at risk of food poisoning.
Retailers must ensure that no more than seven percent of their chickens exceed this level.
Data for 2023 shows that no supermarket has exceeded seven percent.
However, Asda Carry reported the highest average level compared to other retailers.
Data shows that 3.6 percent of samples contained more than 1,000 colony-forming units per gram (CFU/g) of campylobacter. January to March.
The supermarket recorded a level of 3.52 percent between April and June, which amounts to an average of 3.4 percent in the first half of the year.
For comparison: in 2017 and 2018 the percentage was 6.1 and 6.9 percent, just below the safety threshold.
In 2022, only 1.1 percent of all Asda chickens tested throughout the year contained more than 1,000 cfu/g.
Meanwhile, Lidl said it recorded levels of ‘almost four percent’, suggesting these were among the highest rates in the first quarter of the year.
However, this fell to ‘almost two percent’ in the second and third quarters, the report said.
“Our poultry suppliers are working hard to improve biosecurity on farm to reduce campylobacter in poultry flocks,” Lidl said.
‘Our poultry suppliers have implemented innovative factory interventions to reduce campylobacter through the slaughter and production process.’
Waitrose also recorded a rate of 4.04 percent in the first quarter, falling to two percent in the second quarter.
This figure is higher than last year, when just 1.28 per cent of all Waitrose raw chickens tested contained more than 1,000 CFU/g.
A spokesperson for the supermarket told MailOnline: ‘These results reflect the hard work of our farmers and suppliers, combined with our own rigorous data collection and analysis, examining chicken both in the factory and on supermarket shelves.’
In the first quarter of the year, supermarkets Sainsbury’s and Marks and Spencer achieved results of three and less than one percent respectively.
This fell to one percent and zero respectively for each retailer in the second quarter.
A spokesperson for Sainsbury’s said: ‘Safety is our top priority. We are committed to tackling campylobacter in chicken and our regular testing shows levels are well within Food Standards Agency recommendations.”
Morrisons, meanwhile, recorded a level of 2.4 percent based on a sample of 84 chickens tested in the first quarter of 2022, and 2.3 percent based on 86 chickens in the second quarter.
Morrisons has not exceeded the safe limit of seven percent since 2014.
Until July, the Cooperative had not seen any sample contaminated with levels higher than 1,000 CFU/g since the third quarter of 2021.
But between July and September, 3.5 percent of respondents reached the threshold.
A spokesperson for the Co-op told MailOnline: ‘Food safety is a priority and as a responsible retailer we have also carried out our own campylobacter testing in addition to that of the FSA.
‘In line with our commitment to transparency, we have published our results and are pleased that the Q3 2023 results are well below the FSA’s maximum target level.’
Supermarkets must report data on the prevalence of campylobacter in their poultry products every three months so that the FSA can monitor food quality. They share the proportion of their raw broiler chickens that contain more than 1,000 colony-forming units per gram (CFU/g) of campylobacter. At this level, chickens are considered highly contaminated and at risk of food poisoning. Retailers must ensure that no more than seven percent of their chickens exceed this level
Tesco has stopped publishing data as it changes the way it monitors the pathogen in chicken. The findings are therefore not comparable with those of other retailers.
Aldi has not yet updated its web page or provided the figures to MailOnline.
Campylobacter is responsible for an estimated 50,000 cases of illness in England each year and is one of the top four causes of diarrhea in the world.
More worrying is the fact that some strains of bacteria have mutated and developed resistance to antibiotics used by doctors to treat serious diseases.
The latest statistics show that the average Briton consumes 35kg of poultry meat every year.
Apart from the misery and pain of the disease itself, the FSA estimates that the bacteria costs the economy around £900 million a year in terms of NHS treatment and days lost at work.
To avoid food poisoning, people should make sure they cook chicken thoroughly, separate meat from other foods, keep it in the refrigerator and wash their hands and utensils after handling raw meat, the FSA said.
Chicken should also not be washed as this could cause bacteria to splash elsewhere in the kitchen, it added.