title: Epidemiological and Ecological Characterization of the EHEC O104:H4 Outbreak in Hamburg, Germany, 2011.
abstract: In 2011, a large outbreak of entero-hemorrhagic E. coli (EHEC) and hemolytic uremic syndrome (HUS) occurred in Germany. The City of Hamburg was the first focus of the epidemic and had the highest incidences among all 16 Federal States of Germany. In this article, we present epidemiological characteristics of the Hamburg notification data. Evaluating the epicurves retrospectively, we found that the first epidemiological signal of the outbreak, which was in form of a HUS case cluster, was received by local health authorities when already 99 EHEC and 48 HUS patients had experienced their first symptoms. However, only two EHEC and seven HUS patients had been notified. Middle-aged women had the highest risk for contracting the infection in Hamburg. Furthermore, we studied timeliness of case notification in the course of the outbreak. To analyze the spatial distribution of EHEC/HUS incidences in 100 districts of Hamburg, we mapped cases' residential addresses using geographic information software. We then conducted an ecological study in order to find a statistical model identifying associations between local socio-economic factors and EHEC/HUS incidences in the epidemic. We employed a Bayesian Poisson model with covariates characterizing the Hamburg districts as well as incorporating structured and unstructured spatial effects. The Deviance Information Criterion was used for stepwise variable selection. We applied different modeling approaches by using primary data, transformed data, and preselected subsets of transformed data in order to identify socio-economic factors characterizing districts where EHEC/HUS outbreak cases had their residence.
authors.affiliation: Biometry and Data Management, Leibniz Institute for Prevention Research and Epidemiology-BIPS, Bremen, Germany.|Department of Psychology and Cluster of Excellence "Hearing4all", Carl von Ossietzky University Oldenburg, Oldenburg, Germany.
authors.forename: Maike
authors.initials: M
authors.lastname: Tahden
authors.affiliation: Department for Statistics and Econometrics, University of Goettingen, Goettingen, Germany.
authors.forename: Juliane
authors.initials: J
authors.lastname: Manitz
authors.affiliation: Division for Environmental Monitoring, Institut fuer Hygiene und Umwelt, Hamburg, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Baumgardt
authors.affiliation: Centre for Infectious Diseases Epidemiology, Institut fuer Hygiene und Umwelt, Hamburg, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Fell
authors.affiliation: Department for Statistics and Econometrics, University of Goettingen, Goettingen, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kneib
authors.affiliation: Centre for Infectious Diseases Epidemiology, Institut fuer Hygiene und Umwelt, Hamburg, Germany.
authors.forename: Guido
authors.initials: G
authors.lastname: Hegasy
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D004927:Escherichia coli Infections / Q000453:epidemiology*; D000069981:Escherichia coli O104; D005260:Female; D005858:Germany / Q000453:epidemiology; D006463:Hemolytic-Uremic Syndrome / Q000453:epidemiology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D012737:Sex Factors; D012959:Socioeconomic Factors; D012984:Software