The estimated number of foodborne illnesses in the United Kingdom each year has more than doubled.
A scientific review by the Food Standards Agency (FSA) found around 2.4 million cases occur every year. This is up from the 2009 estimate of 1 million.
The FSA said the figures do not indicate an increase in total illness, or any new risk to public health, but provide a better estimation of the proportion of infectious intestinal disease due to food.
Professor Guy Poppy, chief scientific adviser to the FSA, said: “This work gives us a much better idea of the role of food in the spread of all infectious intestinal disease in the U.K. However, this does not mean more people are getting unwell, only that we estimate food is responsible for more existing cases than previously thought.
“We are not changing our advice to consumers and businesses. Instead this research reinforces the need for the highest standards of good personal and food hygiene practices in catering establishments and at home to avoid infection.”
Norovirus and Campylobacter top rankings
The FSA will use the new understanding of foodborne disease to inform efforts to control and reduce the risk of infection from food by all pathogens.
Estimates of foodborne disease in the U.K. in 2018 showed numbers could be as low as 1.8 million or as high as 3.1 million infections. Of the estimated 2.4 million cases, 0.9 million were from 13 known pathogens and 1.4 million for unattributed cases.
Each year, 31 known foodborne pathogens cause an estimated 9 million illnesses and unspecified agents account for 37 million, for a total of 48 million illnesses, according to the U.S. Centers for Disease Control and Prevention. The latest European estimates can be found here.
Only 40 percent of the infectious intestinal disease cases in the U.K. were attributable to the 13 pathogens. The other 60 percent are referred to as unattributed cases. These are infections where the causal pathogen is unknown. Reasons for this include it was not tested for, the test was not sensitive enough to detect it and the pathogen is unknown to science.
Norovirus had the largest estimate with 383,000 cases a year. Campylobacter estimates ranged from 127,000 to 571,000. The next highest was Clostridium perfringens with 85,000. E. coli O157 had 468 foodborne cases and Listeria monocytogenes had 162.
Campylobacter was thought to have the most visits to the general practitioner with 42,500, followed by norovirus with 17,000, Clostridium perfringens with 13,500 and Salmonella at 11,500.
For hospital admissions, Campylobacter was at 3,500, followed by norovirus with 2,200 and Salmonella at 2,100.
Oysters pose highest risk of norovirus
The FSA has also published two reports with new estimates of foodborne norovirus cases. The Norovirus Attribution Study (NoVAS) and an internal technical review.
Foodborne transmission of norovirus was estimated to account for around 380,000 of all 3 million annual U.K. norovirus cases. The 2009 estimate had been 73,000.
Of the five sources identified as posing the most risk for norovirus foodborne transmission, the study revealed that eating out was responsible for 37 percent of foodborne norovirus cases, takeaways 26 percent, oysters at retail 3 percent, raspberries at retail 4 percent, and lettuce at retail 30 percent.
Whilst open-headed lettuce accounted for almost a third of foodborne cases, the risk remains low and is equivalent to getting ill once every 15,000 meals containing it.
Raspberries equates to a norovirus infection once per 12,500 portions. Oysters pose the highest risk per serving with estimates suggesting an average of getting ill once in every 160 portions. Consumers of takeaways and catered food would on average get ill from one in 2,000 meals.
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