Most foodborne infections increased in the Netherlands in 2022 compared to the year before, according to the latest figures.

The most notable outbreak was when 72 people contracted typhoid fever on a ship that housed asylum seekers. It was likely that they were infected by Salmonella Typhi through the ship’s drinking water supply, which was old and located near sewage pipes. There was also a shigellosis outbreak related to travel to Cape Verde that continued into 2023.

Shiga toxin-producing E. coli (STEC) infections saw a sharp rise, with levels in 2022 the highest since 2016. The cause for this increase is unclear, according to the report published by the National Institute for Public Health and the Environment (RIVM).

The number of people sick due to Salmonella or Campylobacter increased this past year, though it did not reach pre-pandemic levels. However, the number of people affected by norovirus did reach 2020 levels. Listeria infections also rose above pre-pandemic levels. 

Campylobacter and Salmonella
based on the surveillance system used, the number of campylobacteriosis cases was estimated at 4,857, up from 4,302 in 2021.

As part of a 3-year project that started in 2021, 451 Campylobacter isolates sent to the RIVM were typed using whole genome sequencing and 83 clusters were detected with a range of two to 28 isolates.

One outbreak affected 12 people between December 2022 and March 2023. Sick people included nine women and three men, aged from 17 to 79 years old. They all lived near the German border. However, the source was not found.

The number of estimated Salmonella cases was 1,290 in 2022, compared to 1,062 in 2021. Salmonella Enteritidis remained the most common cause of salmonellosis.

All related isolates sent to RIVM were typed using WGS and 71 clusters of Salmonella Enteritidis with a range of two to 102 isolates, 44 of Salmonella Typhimurium ranging from two to 21 isolates, and 116 of other serotypes with a range of two to 42 isolates were detected.

The Netherlands only had two patients in the monophasic Salmonella Typhimurium outbreak linked to Ferrero’s Kinder chocolate. A Salmonella Montevideo outbreak with 10 cases went unsolved. Patients ranged in age from 1 to 90 years old and lived across the country. Five were male and five were female. A Salmonella Agona outbreak was linked to cucumbers but there was no microbiological /confirm/iation. Norway had 72 patients, Sweden had 31 and Netherlands had 11.

E. coli and Listeria
In 2022, there were 585 E. coli infections. The most common serotype was O157. This is up from 483 in 2021.

The top frequently mentioned countries for travel-related infections were Egypt, Turkey, and Morocco. For domestic cases, 357 of 375 consumed meat and 149 of 341 had eaten raw or undercooked meat. Also, 33 of 351 had drunk raw milk and many had contact with animals in the week before falling ill.

Sixteen patients developed hemolytic uremic syndrome (HUS), including three with STEC O157, five with non-O157 and eight for whom no isolate was available. Patients included five children aged 0 to 13; two people aged 20 to 29 and the other nine were aged 50 to 90.

Four people died directly or indirectly from STEC infection including one child and two adults over the age of 55 who had HUS and an adult older than 60 without HUS.

In late 2022, a national E. coli O157 outbreak was detected based on WGS data. A total of 14 patients ranging in age from 7 to 77 were identified. Patient interviews found beef, specifically filet américain, ground meat or burgers, to be the likely source. However, trace back work by the NVWA did not identify a producer or production location.

More than 100 people with listeriosis were recorded, including eight pregnant women, and 12 people died. Overall, 97 of the 102 patients were admitted to hospital. In 2021, 94 cases were recorded. The median age of sick people in 2022 was 75 with a range from 28 to 94 years old and 63 percent were male.

There were seven clusters wher an investigation by the NVWA found persistent contamination at a production site. Six clusters, which added between one and six isolates in 2022, were linked to different fish processing plants. One cluster from previous years grew with another six human isolates. The source was a type of sausage made from liver by a meat processor.

Shigella stats
In 2022, 427 patients with shigellosis were reported, bringing the number back to almost the same as before the pandemic. Of these, 260 were infected abroad. There were 213 cases in 2021.

One Shigella sonnei cluster had 37 cases related to travel to Cape Verde that occurred in the last quarter of the year. Patients for whom information was available indicated they had stayed at resorts on the same island of one hotel chain. Foodborne and possibly person-to-person transmission was suspected, but the source remains unknown.

A total of 258 patients including 159 from the EU, 95 from the UK and four in the U.S. have been linked to the same cluster. This covers 221 WGS-confirmed patients reported after November 2021.

In one case of foodborne botulism, Clostridium botulinum was detected in a patient sample but the source was not found. A total of six Brucellosis patients, four women between 52 and 65 years old and two men between 61 and 69, were recorded. Two cases were linked to raw milk cheese from Bangladesh and raw sheep’s milk in Bosnia and Herzegovina.