First European detection and genomic analysis of Francisella tularensis subsp. tularensis in a traveler returning from Canada

Tularemia is a zoonotic disease caused by the gram negative coccobacillus Francisella tularensis, a Biosafety Level 3 pathogen and potential bioterrorism agent. We report here the first European human case of tularemia caused by F. tularensis subsp. tularensis in a patient returning from Canada to Switzerland. Successful culture and genomic characterisation revealed that the isolate belongs to the A.I lineage of F. tularensis subsp. tularensis , and clusters with strains from Canada and Alaska. This work underscores the importance of rapid diagnostics combined with genomic analysis and molecular characterization for detecting non-endemic pathogens and evaluating potential bioterrorism threats. • First European human tularemia case due to Francisella tularensis subsp. tularensis • Infection is linked to travel in Canada and confirmed after return to Switzerland. • Sequencing assigned the isolate to the A.I clade, clustering with Canadian strains. • cgMLST and core-SNP analysis led to precise genomic characterization of the isolate.