Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2024 Aug;71(5):560-567.
doi: 10.1111/zph.13157. Epub 2024 May 20.

Salmonella Typhimurium caused an unprecedentedly large foodborne outbreak in Finland in 2021

Satu-Mari Lehti  1 , Ole Andersen  2 , Jaana Leppäaho-Lakka  3 , Eija Suominen  4 , Anni Vainio  1 , Maire Matsinen  3 , Henry Kuronen  5 , Ruska Rimhanen-Finne  1
Affiliations

Salmonella Typhimurium caused an unprecedentedly large foodborne outbreak in Finland in 2021

Satu-Mari Lehti et al. Zoonoses Public Health. 2024 Aug.

Abstract

Aims: Salmonella infections are significant causes of foodborne outbreaks in the European Union. This study investigates a sudden increase in gastroenteritis patients in the hospital district of Central Finland in June 2021. The primary aim was to study the outbreak's magnitude and source of the outbreak.

Methods and results: Epidemiological, microbiological, environmental and traceback investigations were conducted. Over 700 persons fell ill during the outbreak caused by Salmonella Typhimurium associated with a daycare lunch. Similar S. Typhimurium was found in the patients and a vegetable mix containing iceberg lettuce, cucumber and peas served during lunch. The traceback investigation revealed that the batch information of vegetables from the wholesaler was not complete. The wholesaler had received quality complaints about the iceberg lettuce from the central kitchen. The manufacturer did not test the suspected batch for Salmonella since the production plant had given a certificate declaring it Salmonella negative.

Conclusions: The most suspect ingredient was one batch of iceberg lettuce due to quality complaints. The lettuce had not been served in two daycare centres without cases. We recommend that in order to enable thorough microbiological investigation, institutional kitchens store the food samples separately as part of the internal quality control and that food items should always be tested when Salmonella contamination in an outbreak is suspected.

Keywords: Salmonella Typhimurium; Finland; daycare centre; foodborne outbreak; salmonellosis.

PubMed Disclaimer

References

REFERENCES

    1. CLSI. (2018). Performance standards for antimicrobial disk and dilution susceptibility tests for bacteria isolated from animals. CLSI Standard VET01. Clinical and Laboratory Standards Institute. https://clsi.org/media/2325/vet01ed5_sample.pdf
    1. CLSI. (2020). Performance standards for antimicrobial disk and dilution susceptibility tests for bacteria isolated from animals. CLSI supplement VET01S. Clinical and Laboratory Standards Institute. https://clsi.org/media/m1gppkx2/vet01sed5_sample.pdf
    1. EFSA, & ECDC. (2022). The European Union one health 2021 zoonoses report. EFSA Journal, 20, 7666. https://doi.org/10.2903/j.efsa.2022.7666
    1. Goverment Decree. (2011). Valtioneuvoston asetus elintarvikkeiden ja veden välityksellä leviävien epidemioiden selvittämisestä. [Government Decree concerning the follow‐up and reporting of food‐ and waterborne outbreaks]. Pub. L. No. 1365‐2011. https://www.finlex.fi/fi/laki/alkup/2011/20111365
    1. Guibourdenche, M., Roggentin, P., Mikoleit, M., Fields, P. I., Bockemühl, J., Grimont, P. A., & Weill, F. X. (2010). Supplement 2003‐2007 (No. 47) to the White‐Kauffmann‐Le minor scheme. Research in Microbiology, 161, 26–29. https://doi.org/10.1016/j.resmic.2009.10.002

LinkOut - more resources