The number of people diagnosed with a foodborne illness in Denmark fell sharply in 2020, according to an annual report on infections.

The report by the National Food Institute, Technical University of Denmark, Statens Serum Institut (SSI) and the Danish Veterinary and Food Administration (Fødevarestyrelsen) found Coronavirus pandemic restrictions played a role in the decline.

A significant reduction in travel was listed as the primary reason for the sharp decrease in patients. It was also attributed to the fact that Danish people were less likely to visit the doctor with minor illness symptoms during the lockdown.

“In addition to the changes in Danes’ travel patterns and the reduced number of doctor’s visits that were bought about by the COVID-19 epidemic, the overall corona restrictions such as the closure of restaurants and canteens contributed to the decrease in registered foodborne illness cases in 2020,” said Luise Müller, an epidemiologist from SSI.

A third of 5,000 Danes who are registered in the health system every year because they are infected with Salmonella or Campylobacter contract the infection abroad, according to Fødevarestyrelsen.

The proportion of travel-related Campylobacter went down from 28 percent to 9 percent of all cases in Denmark. For Salmonella, a similar reduction was seen from 42 percent to 20 percent.

Campylobacter and Salmonella results
Four bacteria were the main cause of registered illnesses: Campylobacter, Salmonella, Shiga toxin-producing E. coli (STEC) and Yersinia enterocolitica. For Campylobacter, Salmonella and STEC, a decrease ranging from 29 to 45 percent was seen from 2019 to 2020. For information on outbreaks see this previous article.

Campylobacter was the leading cause of foodborne illness with 3,742 confirmed cases in 2020. However, 31 percent fewer cases were recorded compared with the previous year.

A quarter of 1,224 conventional samples of non-heat treated chilled broiler meat leg skin samples were positive for Campylobacter at slaughter compared to half of 95 organic or free range samples. At retail, 15 percent of 436 conventional and 34 percent of 192 organic or free range samples were positive. Two thirds of 64 samples were positive from imported retail samples.

From 985 neck skin samples of Campylobacter in broiler flocks at slaughter, 7 percent were above 1,000 colony forming units per gram.

Salmonella infections – which are the second leading cause of foodborne illness in Denmark – decreased by 45 percent to 614 lab-confirmed infections.

More than 100 infections were due to Salmonella Enteritidis, followed by the monophasic variant of Salmonella Typhimurium, Salmonella Typhimurium, Dublin, Strathcona and Kottbus.

Three samples of Danish products made from pork, intended to be cooked, were positive from 395 tests for Salmonella.

E. coli, Listeria and Yersinia
STEC decreased from 630 in 2019 to 448 cases in 2020. E. coli O157 was mainly responsible followed by O146 and O103.

Listeria infections dropped from 62 in 2019 to 43 in 2020. From 13 samples of Danish produced ready-to-eat (RTE) foods, two made from pork were positive for Listeria.

For Yersinia, a 10 percent increase from 374 to 413 in 2019 to 2020 was registered. One explanation offered was that outbreaks of Yersinia enterocolitica are often caused by exposure to common food items consumed at home so restrictions implemented in 2020 due to COVID-19, had limited impact.

Histamine was found in one of 30 batches of Danish and non-Danish fishery products. Findings in the offending batch of mackerel during a border inspection didn’t exceed the limit set in regulation.