A Modeling Framework to Describe the Transmission of Bluetongue Virus within and between Farms in Great Britain

Abstract

BackgroundRecently much attention has been given to developing national-scale micro-simulation models for livestock diseases that can be used to predict spread and assess the impact of control measures. The focus of these models has been on directly transmitted infections with little attention given to vector-borne diseases such as bluetongue, a viral disease of ruminants transmitted by Culicoides biting midges. Yet BT has emerged over the past decade as one of the most important diseases of livestock.Methodology/Principal FindingsWe developed a stochastic, spatially-explicit, farm-level model to describe the spread of bluetongue virus (BTV) within and between farms. Transmission between farms was modeled by a generic kernel, which includes both animal and vector movements. Once a farm acquired infection, the within-farm dynamics were simulated based on the number of cattle and sheep kept on the farm and on local temperatures. Parameter estimates were derived from the published literature and using data from the outbreak of bluetongue in northern Europe in 2006. The model was validated using data on the spread of BTV in Great Britain during 2007. The sensitivity of model predictions to the shape of the transmission kernel was assessed.Conclusions/SignificanceThe model is able to replicate the dynamics of BTV in Great Britain. Although uncertainty remains over the precise shape of the transmission kernel and certain aspects of the vector, the modeling approach we develop constitutes an ideal framework in which to incorporate these aspects as more and better data become available. Moreover, the model provides a tool with which to examine scenarios for the spread and control of BTV in Great Britain.

Effect of biosecurity measures and early detection systems, mitigation measures and surveillance strategies on the spread of HPAI and LPAI between farms

“…The European Food Safety Authority reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors. (Süss et al, 1994) Time interval (Swayne, 2006) Study population (Swayne, 2012) Not relevant outcomes Not relevant outcomes Not relevant outcomes (Swayne et al, 2015) Not relevant outcomes (Szeleczky et al, 2010) Not relevant outcomes (Szmaragd et al, 2009) Not relevant outcomes (Tabynov et al, 2014) Not relevant outcomes The present document has been produced and adopted by the bodies identified above as authors. This task has been carried out exclusively by the authors in the context of a contract between the European Food Safety Authority and the authors, awarded following a tender procedure.…”

MAPRA: Modelling Animal Pathogens: Review and Adaptation

“…However, a number of these aspects were addressed by the following adaptation to this model published in 2009 by the same group of authors: Szmaragd, C., Wilson, A.J., Carpenter, S., Wood, J.L.N., Mellor, P.S., Gubbins, S., 2009. A modeling framework to describe the transmission of bluetongue virus within and between farms in Great Britain.…”

Schmallenberg virus: State of Art

“…al., 2008;Szmaragd et. al., 2009), was developed and fitted to data on the seroprevalence of SBV in cattle and sheep farms in Belgium (Méroc et.…”