Nature. 2007 Feb 8;445(7128):E12; discussion E12-3.
Veterinary epidemiology: vaccination strategies for foot-and-mouth disease.
Kitching RP, Taylor NM, Thrusfield MV.
National Centre for Foreign Animal Diseases, Winnipeg R3E 3M4, Canada.
Comment on:
Abstract
When foot-and-mouth disease struck the United Kingdom in 2001, the traditional ‘stamping out’ policy of 1967-68 was supplemented by the pre-emptive culling of animals in premises contiguous to infected premises. A model proposed by Tildesley et al. indicates that the introduction of vaccination should at least halve the number of premises that would need to be subjected to culling in the event of another outbreak. We contest, however, that the overlapping confidence intervals of the outputs of their model, and the inconsistency of their results compared with those from previous models, call into question the model’s value as a decision tool, while adding little to the recognized tenet of ring vaccination.
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Rev Sci Tech. 2006 Apr;25(1):293-311.
Use and abuse of mathematical models: an illustration from the 2001 foot and mouth disease epidemic in the United Kingdom.
Kitching RP, Thrusfield MV, Taylor NM.
National Centre for Foreign Animal Disease, 1015 Arlington St, Winnipeg, Manitoba R3E 3M4, Canada.
Abstract
Foot and mouth disease (FMD) is a major threat, not only to countries whose economies rely on agricultural exports, but also to industrialised countries that maintain a healthy domestic livestock industry by eliminating major infectious diseases from their livestock populations. Traditional methods of controlling diseases such as FMD require the rapid detection and slaughter of infected animals, and any susceptible animals with which they may have been in contact, either directly or indirectly. During the 2001 epidemic of FMD in the United Kingdom (UK), this approach was supplemented by a culling policy driven by unvalidated predictive models. The epidemic and its control resulted in the death of approximately ten million animals, public disgust with the magnitude of the slaughter, and political resolve to adopt alternative options, notably including vaccination, to control any future epidemics. The UK experience provides a salutary warning of how models can be abused in the interests of scientific opportunism.
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Vet J. 2005 Mar;169(2):197-209.
A review of foot-and-mouth disease with special consideration for the clinical and epidemiological factors relevant to predictive modelling of the disease.
Kitching RP, Hutber AM, Thrusfield MV.
National Centre for Foreign Diseases, Winnipeg, Manitoba, Canada R3E 3M4.
Comment in:
Abstract
Modelling the epidemiology of foot-and-mouth disease (FMD) has been undertaken since the early 1970s. We review here clinical factors and modelling procedures that have been used in the past, differentiating between those that have proved to be more relevant in controlling FMD epidemics, and those that have showed less significance. During the 2001 UK FMD epidemic, many previously developed FMD models were available for consideration and use. Accurate epidemiological models can become useful tools for determining relevant control policies for different scenarios and, conversely, inaccurate models may become an abuse for disease control. Inaccuracy presents two opposing difficulties. Firstly, too much control (in terms of animal slaughter for 2001) would negatively impact the farming community for many subsequent years, whilst too little control would permit an epidemic to persist. Accuracy however, presents the optimal permutation of control measures that could be implemented for a given set of conditions, and is a prerequisite to boosting public confidence in the use of epidemiological models for future epidemics.
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Prev Vet Med. 2008 Jun 15;85(1-2):107-24. Epub 2008 Mar 6.
Modelling foot-and-mouth disease: a comparison between the UK and Denmark.
Department of Biological Sciences, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK. M.J.Tildesley@warwick.ac.uk
Abstract
Whilst the UK 2001 FMD (foot-and-mouth disease) outbreak provides an extremely rich source of spatio-temporal epidemic data, it is not clear how the models and parameters from the UK can be translated to other scenarios. Here we consider how the model framework used to capture the UK epidemic can be applied to a hypothetical FMD outbreak in Denmark. Whilst pigs played a relatively minor role in the UK epidemic (being the infected animal on just 18 farms), they dominate the Danish livestock landscape. In addition, it is not clear whether transmission parameters from the UK will transfer to Denmark where farming practices may be significantly different. We therefore explore a large volume of high-dimensional parameter space, but seek to relate final epidemic size, risk of spread to Danish islands and potential success of control measures, to early indicators of epidemic dynamics. The results of this extensive modelling exercise therefore allow us to provide timely advice on control options based on the observed behaviours of the first few generations.
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Acta Virol. 2010;54(4):311-3.
Effect of the route of foot-and-mouth disease virus inftection of piglets on the course of disease.
Li D, Bai XW, Sun P, Fu YF, Xie BX, Lu ZJ, Chen YL, Cao WJ, Liu ZX.
Abstract
Three different routes of Foot-and-mouth disease virus (FMDV) infection of piglets, namely intranasal (i.n.) through drops, intradermal (i.d.) into the foot, and intramuscular (i.m.) were compared regarding the onset and severity of the disease. The results showed that the i.d. injection of the virus resulted in the fastest onset of the disease. The i.m. injection led to a delayed onset, but the final effect was identical with i.d. injection. Moreover, the i.m. injection was simpler to perform and easier to evaluate. Therefore, the i.m. injection of piglets is recommended as the optimal infection route for evaluation of the FMDV vaccine potency. Keywords: Foot-and-mouth disease virus; challenge routes; intranasal drops; intradermal injection; intramuscular injection; pig.
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Epidemiol Infect. 2005 Oct;133(5):767-83.
Re-assessing the likelihood of airborne spread of foot-and-mouth disease at the start of the 1967-1968 UK foot-and-mouth disease epidemic.
Gloster J, Freshwater A, Sellers RF, Alexandersen S.
Met Office, Institute for Animal Health, Ash Road, Pirbright, Woking, Surrey, UK. john.gloster@bbsrc.ac.uk
Abstract
The likelihood of airborne spread of foot-and-mouth disease at the start of the 1967-1968 epidemic is re-assessed in the light of current understanding of airborne disease spread. The findings strongly confirm those made at the time that airborne virus was the most likely cause of the rapid early development of the disease out to 60 km from the source. This conclusion is reached following a detailed epidemiological, meteorological and modelling study using original records and current modelling techniques. The role played by ‘lee waves’ as the mechanism for the spread is investigated. It is thought that they played little part in influencing the development of the epidemic. A number of lessons learned from the work are drawn, identifying the need for further research on the quantity and characteristics of airborne virus. The results are also used to illustrate what advice would have been available to disease controllers if the outbreak had occurred in 2004.
