title: Data-driven network modelling of disease transmission using complete population movement data: spread of VTEC O157 in Swedish cattle.
abstract: European Union legislation requires member states to keep national databases of all bovine animals. This allows for disease spread models that includes the time-varying contact network and population demographic. However, performing data-driven simulations with a high degree of detail are computationally challenging. We have developed an efficient and flexible discrete-event simulator SimInf for stochastic disease spread modelling that divides work among multiple processors to accelerate the computations. The model integrates disease dynamics as continuous-time Markov chains and livestock data as events. In this study, all Swedish livestock data (births, movements and slaughter) from July 1st 2005 to December 31st 2013 were included in the simulations. Verotoxigenic Escherichia coli O157:H7 (VTEC O157) are capable of causing serious illness in humans. Cattle are considered to be the main reservoir of the bacteria. A better understanding of the epidemiology in the cattle population is necessary to be able to design and deploy targeted measures to reduce the VTEC O157 prevalence and, subsequently, human exposure. To explore the spread of VTEC O157 in the entire Swedish cattle population during the period under study, a within- and between-herd disease spread model was used. Real livestock data was incorporated to model demographics of the population. Cattle were moved between herds according to real movement data. The results showed that the spatial pattern in prevalence may be due to regional differences in livestock movements. However, the movements, births and slaughter of cattle could not explain the temporal pattern of VTEC O157 prevalence in cattle, despite their inherently distinct seasonality.
authors: Department of Clinical Sciences, Swedish University of Agricultural Sciences, 750 07, Uppsala, Sweden. stefan.widgren@sva.se.|Department of Disease Control and Epidemiology, National Veterinary Institute, 751 89, Uppsala, Sweden. stefan.widgren@sva.se.
authors: Stefan
authors: 0000-0001-5745-2284
authors: S
authors: Widgren
authors: Division of Scientific Computing, Department of Information Technology, Uppsala University, 751 05, Uppsala, Sweden.
authors: Stefan
authors: S
authors: Engblom
authors: Division of Scientific Computing, Department of Information Technology, Uppsala University, 751 05, Uppsala, Sweden.
authors: Pavol
authors: P
authors: Bauer
authors: Department of Disease Control and Epidemiology, National Veterinary Institute, 751 89, Uppsala, Sweden.|Department of Animal Environment and Health, Swedish University of Agricultural Sciences, Box 234, 532 23, Skara, Sweden.
authors: Jenny
authors: J
authors: Frössling
authors: Department of Clinical Sciences, Swedish University of Agricultural Sciences, 750 07, Uppsala, Sweden.
authors: Ulf
authors: U
authors: Emanuelson
authors: Department of Disease Control and Epidemiology, National Veterinary Institute, 751 89, Uppsala, Sweden.
authors: Ann
authors: A
authors: Lindberg
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000635:transmission*; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000635:transmission / Q000662:veterinary*; D019453:Escherichia coli O157; D015233:Models, Statistical; D013269:Stochastic Processes; D013548:Sweden / Q000453:epidemiology