Swedish officials have traced the source of a Salmonella outbreak to a brand of chocolate wafers from Poland.

Between late December 2020 and early April 2021, 32 people living in 15 counties fell ill after infection with the same type of Salmonella Enteritidis. Nineteen patients were children under the age of 10 while nine people were above 70 years old. Seventeen females and 15 males were affected.

The outbreak was investigated by local infection control units, National Food Agency (Livsmedelsverket) and the Public Health Agency of Sweden (Folkhälsomyndigheten) with the first updat in February when 12 people were sick.

Through the national microbial surveillance program, the Public Health Agency of Sweden identified several cases infected with the same type of Salmonella Enteritidis.

Local infection control units interviewed sick people about what they ate and wher they bought food from before they became sick. This identified the suspected source of infection as a kind of chocolate wafer sold in Axfood stores.

In analyzes by the National Food Agency, Salmonella was identified in chocolate wafers of the Eldorado brand. Axfood issued a recall of the batch in question, which came from Poland.

Further testing showed the isolate from chocolate wafers was the same type as that found in patients which determined the source of infection.

The recall applies to Eldorado chocolate wafers 415-gram with a best before date of Sept. 15, 2021 and batch number 350.3 E400:56. Axfood urged consumers who bought the product in question to return it to the store wher it was purchased.

“We take this extremely seriously, and are now investigating with the supplier how it could have happened and how we can ensure that something similar does not happen again,” said Axfood’s Quality Manager Susanna Wadegård.

Impact of COVID-19 measures on foodborne infections
Meanwhile, a decline in many diseases in Sweden this past year, including foodborne infections, has been linked to measures put in place during the COVID-19 pandemic.

Factors contributing to the fall included people following advice and recommendations, having fewer close contacts and gatherings, keeping their distance, avoiding travel abroad and increased attention on hand hygiene. The reduction in healthcare visits in 2020 may also have affected the incidence of certain infections.

The number of Campylobacter infections decreased for the fourth year in a row despite a large outbreak during the summer and autumn caused by contaminated chicken. The figure was almost 6,700 in 2019 and it was 3,429 in 2020.

Salmonella infections went down from nearly 2,000 in 2019 to 826 in 2020, EHEC fell from 755 in 2019 to 491 in 2020; Yersinia declined from 393 in 2019 to 221 in 2020; Listeriosis went from 113 in 2019 to 88 in 2020 and Cryptosporidium dropped from 1,088 to 638.

Detailed reports on each infectious agent will be published later this year. A further aim is to do a more thorough evaluation of the effects from the pandemic on other diseases.