title: Cross-border outbreak of Salmonella enterica ssp. enterica serovar Bovismorbificans: multiple approaches for an outbreak investigation in Germany and Switzerland.
abstract: OBJECTIVE
  In July 2014, an outbreak of Salmonella enterica ssp. enterica serovar Bovismorbificans was detected in Switzerland. The goal of the outbreak investigation was to rapidly identify and eliminate the contamination source in order to prevent new cases.
  
  
  METHODS
  A case-case study design was applied comprising reported cases of S. Bovismorbificans and cases of other serovars. A trawling questionnaire was administered by telephone interview. Data were collected for 34 cases (20 S. Bovismorbificans and 14 Salmonella spp.) pertaining to food consumption during the 72 hours prior to symptom onset.
  
  
  RESULTS
  A statistically significant association between an S. Bovismorbificans infection and the consumption of 'salads' (odds ratio [OR] 14.3, 95% confidence interval [CI] 1.47-138.27) as well as the consumption of 'sprouts' (OR 10.6, 95% CI 1.16-97.59) was found. Principal places of consumption of 'salads' and 'sprouts' in outbreak cases were restaurants in southern Germany (80.0%, 95% CI 56.3%-94.3%). Microbiological analysis in Germany identified S. Bovismorbificans on sprouts, and genotype analysis confirmed that Swiss and German cases shared the same outbreak strain. The contaminated products were removed from the market in Germany, preventing an on-going outbreak.
  
  
  CONCLUSIONS
  The combination of the applied methods and the collaboration between the two countries proved to be crucial elements of this investigation. A series of sprouts-associated salmonellosis outbreaks underpin the importance of this vegetable as a potential food-borne pathogen carrier.
authors.affiliation: Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Switzerland.
authors.forename: Astrid M
authors.initials: AM
authors.lastname: Knoblauch
authors.affiliation: Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Switzerland.
authors.forename: Martin W
authors.initials: MW
authors.lastname: Bratschi
authors.affiliation: Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Switzerland.
authors.forename: Meike K
authors.initials: MK
authors.lastname: Zuske
authors.affiliation: Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Switzerland.
authors.forename: Denise
authors.initials: D
authors.lastname: Althaus
authors.affiliation: Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Switzerland.
authors.forename: Roger
authors.initials: R
authors.lastname: Stephan
authors.affiliation: Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Switzerland.
authors.forename: Herbert
authors.initials: H
authors.lastname: Hächler
authors.affiliation: Federal Food Safety and Veterinary Office, Bern, Switzerland.
authors.forename: Andreas
authors.initials: A
authors.lastname: Baumgartner
authors.affiliation: Robert Koch Institute, Division of Enteropathogenic Bacteria and Legionella, National Reference Centre for Salmonella and other Bacterial Enterics, Wernigerode, Germany.
authors.forename: Rita
authors.initials: R
authors.lastname: Prager
authors.affiliation: Robert Koch Institute, Division of Enteropathogenic Bacteria and Legionella, National Reference Centre for Salmonella and other Bacterial Enterics, Wernigerode, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Rabsch
authors.affiliation: Federal Office of Public Health, Berne, Switzerland.
authors.forename: Ekkehardt
authors.initials: E
authors.lastname: Altpeter
authors.affiliation: Federal Office of Public Health, Berne, Switzerland.
authors.forename: Marianne
authors.initials: M
authors.lastname: Jost
authors.affiliation: Federal Office of Public Health, Berne, Switzerland.
authors.forename: Mirjam
authors.initials: M
authors.lastname: Mäusezahl
authors.affiliation: Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Switzerland; Institute for Social and Preventive Medicine, University of Zurich, Switzerland.
authors.forename: Christoph
authors.initials: C
authors.lastname: Hatz
authors.affiliation: Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Switzerland.
authors.forename: Sabine
authors.initials: S
authors.lastname: Kiefer
mesh_terms: D016022:Case-Control Studies; D016358:Contact Tracing / Q000379:methods*; D004196:Disease Outbreaks; D005858:Germany / Q000453:epidemiology; D006801:Humans; D007391:International Cooperation; D012147:Restaurants; D012478:Salmonella Food Poisoning / Q000453:epidemiology* / Q000382:microbiology; D019779:Salmonella enterica; D013557:Switzerland / Q000453:epidemiology; D014675:Vegetables / Q000382:microbiology*