Cross-border outbreak of listeriosis caused by cold-smoked salmon, revealed by integrated surveillance and whole genome sequencing (WGS), Denmark and France, 2015 to 2017

Susanne Schjørring; Sofie Gillesberg Lassen; Tenna Jensen; Alexandra Moura; Jette S Kjeldgaard; Luise Müller; Stine Thielke; Alexandre Leclercq; Mylene M Maury; Mathieu Tourdjman; Marie-Pierre Donguy; Marc Lecuit; Steen Ethelberg; Eva M Nielsen

doi:10.2807/1560-7917.ES.2017.22.50.17-00762

Cross-border outbreak of listeriosis caused by cold-smoked salmon, revealed by integrated surveillance and whole genome sequencing (WGS), Denmark and France, 2015 to 2017

Euro Surveill. 2017 Dec;22(50):17-00762. doi: 10.2807/1560-7917.ES.2017.22.50.17-00762.

Authors

Affiliations

¹ Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen, Denmark.
² Department of Infectious Disease Epidemiology and Prevention, Statens Serum Institut, Copenhagen, Denmark.
³ The Danish Veterinary and Food Administration, Copenhagen, Denmark.
⁴ Institut Pasteur, National Reference Centre and WHO collaborating Center for Listeria, Biology of Infection Unit, Paris, France.
⁵ National Food Institute, Technical University of Denmark, Kgs. Lyngby, Denmark.
⁶ Santé Publique France, the French Public Health Agency, Saint-Maurice, France.
⁷ Ministry of Agriculture, and Forestry, Paris, France.
⁸ Paris Descartes University, Sorbonne Paris Cité, Division of Infectious Diseases, Necker-Enfants Malades University Hospital, Institut Imagine, F-75743 Paris, France  .

PMID: 29258647
PMCID: PMC5743096
DOI: 10.2807/1560-7917.ES.2017.22.50.17-00762

Abstract

In August 2017, an outbreak of six listeriosis cases in Denmark was traced to cold-smoked salmon, using epidemiological investigations and whole-genome sequencing (WGS) analyses. Exchange of genome sequences allowed identification in France of a food isolate from a salmon-derived product and a human isolate from 2016 within the same cgMLST cluster as the Danish isolates (L2-SL8-ST8-CT771). The salmon product came from a third European Union country. WGS can rapidly link human cases and food isolates across Europe.

Keywords: Cross-border outbreak; WGS; cold-smoked salmon; food-borne infections; listeriosis; surveillance; whole genome sequencing.

MeSH terms

Adult
Aged
Aged, 80 and over
Animals
Denmark / epidemiology
Disease Outbreaks / statistics & numerical data*
Emigration and Immigration
Female
Foodborne Diseases* / epidemiology
Foodborne Diseases* / microbiology
France / epidemiology
Genome, Bacterial / genetics*
Humans
Listeria monocytogenes / genetics*
Listeria monocytogenes / isolation & purification
Listeriosis / diagnosis
Listeriosis / epidemiology*
Listeriosis / microbiology
Male
Middle Aged
Molecular Epidemiology
Multilocus Sequence Typing
Salmon / microbiology*
Sequence Analysis, DNA
Whole Genome Sequencing