Insights into recurring multi-country outbreaks of Salmonella Strathcona associated with tomatoes, Europe, 2011 to 2024

Published on 16 October 2025 Updated on 10 August 2026

Notifications of Salmonella Strathcona infections increased in Europe in 2023 prompting a multi-country outbreak investigation. We aimed to describe the epidemiology of S. Strathcona infections in 17 European countries 2011-2024, investigate the genetic relatedness of S. Strathcona isolates and identify the vehicle. Cases were persons residing in the study area and with a laboratory-confirmed S. Strathcona infection 2011-2024. Confirmed cases had a S. Strathcona isolate clustering with the outbreak reference strain in core genome multilocus sequence typing (cgMLST) within 7 allelic differences (AD) and possible cases within 8-13 AD. Probable cases had an epidemiological link to a confirmed case and non-outbreak cases had an isolate > 13 AD from the outbreak reference strain. Since 2011, 662 S. Strathcona infections have been identified: 469 confirmed, 161 probable, 13 possible and 19 non-outbreak cases. Median age of the cases was 34 years (IQR: 19-58 years) and 306 (47.5%) were notified in 2023-2024. Most sequenced isolates (469/496; 94.5%) were highly genetically related (≤ 7 AD) over time and across countries, compatible with a common source. Epidemiological and traceback investigations identified small tomatoes from Sicily as the suspect food vehicle. Stringent control measures at the source are needed to stop the contamination and prevent future cases.

Author(s): Brait Vivien, Böff Lena, Zmarlak-Feher Natalia Marta, Jourdan-Da Silva Nathalie, Mazzilli Sara, Pardos de la Gandara Maria, Moura Alexandra, Mossong Joel, Ernst Corinna, Ragimbeau Catherine, Pijnacker Roan, Lanzl Maren, Brandal Lin T, Lange Heidi, Stephan Roger, Biggel Michael, Raess Michelle, Daniel Ondřej, Spačková Michaela, Clarke Christina, Cormican Martin, Colgan Aoife, Garvey Patricia, Mckeown Paul, Dryselius Rikard, Karamehmedovic Nadja, Grilc Eva, Trkov Marija, Pirš Mateja, Brown Derek, Browning Lynda, Hoban Ann, Godbole Gauri, Painset Anais, Chattaway Marie Anne, Vainio Anni, Rimhanen-Finne Ruska, Fischer Jennie, Lamparter Marina C, Mattheus Wesley, Commans Florian, Grginić Ana Gverić, Mlinarić Ivan, Pem-Novosel Iva, Kurečić Filipović Sanja, Ferencak Ivana, Jurić Dragan, Niskanen Taina, Jernberg Cecilia, Rizzi Valentina, Sarno Eleonora, Kornschober Christian, Wolfsbauer Andreas, Werber Dirk, Simon Sandra, Gymoese Pernille, Ethelberg Steen, Müller Luise, Maritschnik Sabine, Meinen Anika, Pietsch Michael

Publishing year: 2025

Pages: 30-45

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