title: Trace-back and trace-forward tools developed ad hoc and used during the STEC O104:H4 outbreak 2011 in Germany and generic concepts for future outbreak situations.
abstract: The Shiga toxin-producing Escherichia coli O104:H4 outbreak in Germany in 2011 required the development of appropriate tools in real-time for tracing suspicious foods along the supply chain, namely salad ingredients, sprouts, and seeds. Food commodities consumed at locations identified as most probable site of infection (outbreak clusters) were traced back in order to identify connections between different disease clusters via the supply chain of the foods. A newly developed relational database with integrated consistency and plausibility checks was used to collate these data for further analysis. Connections between suppliers, distributors, and producers were visualized in network graphs and geographic projections. Finally, this trace-back and trace-forward analysis led to the identification of sprouts produced by a horticultural farm in Lower Saxony as vehicle for the pathogen, and a specific lot of fenugreek seeds imported from Egypt as the most likely source of contamination. Network graphs have proven to be a powerful tool for summarizing and communicating complex trade relationships to various stake holders. The present article gives a detailed description of the newly developed tracing tools and recommendations for necessary requirements and improvements for future foodborne outbreak investigations.
authors.affiliation: Federal Institute for Risk Assessment, Berlin, Germany. armin.weiser@bfr.bund.de
authors.forename: Armin A
authors.initials: AA
authors.lastname: Weiser
authors.forename: Stefan
authors.initials: S
authors.lastname: Gross
authors.forename: Anika
authors.initials: A
authors.lastname: Schielke
authors.forename: Jan-Frederik
authors.initials: JF
authors.lastname: Wigger
authors.forename: Andrea
authors.initials: A
authors.lastname: Ernert
authors.forename: Julian
authors.initials: J
authors.lastname: Adolphs
authors.forename: Alexandra
authors.initials: A
authors.lastname: Fetsch
authors.forename: Christine
authors.initials: C
authors.lastname: Müller-Graf
authors.forename: Annemarie
authors.initials: A
authors.lastname: Käsbohrer
authors.forename: Olaf
authors.initials: O
authors.lastname: Mosbach-Schulz
authors.forename: Bernd
authors.initials: B
authors.lastname: Appel
authors.forename: Matthias
authors.initials: M
authors.lastname: Greiner
mesh_terms: D016000:Cluster Analysis; D004196:Disease Outbreaks; D004534:Egypt; D004756:Enterobacteriaceae Infections / Q000453:epidemiology* / Q000382:microbiology; D005506:Food Contamination / Q000032:analysis; D005516:Food Microbiology; D005517:Foodborne Diseases / Q000453:epidemiology* / Q000382:microbiology; D005858:Germany / Q000453:epidemiology; D006801:Humans; D010936:Plant Extracts; D054323:Shiga-Toxigenic Escherichia coli / Q000302:isolation & purification / Q000472:pathogenicity*; D029910:Trigonella / Q000382:microbiology
chemical_list: D010936:Plant Extracts; C056164:fenugreek seed meal