Acta Veterinaria Brno, 2006, 74 (4): 632-633

Book Review

Biological disaster of animal origin. The role and preparedness of veterinary and public health service. Scientific and Technical Review. Volume 25 (1), April 2006. OIE, Paris, 462 pages. ISBN O253-1933 and ISBN 92-9044-661-7

The publication was edited by Prof. Dr M. Hugh-Jones (USA) who wrote also the Introduction, Conclusion and a paper on accidental and international animal disease outbreaks - assessing the risk and preparing an effective response. The book is subdivided in 4 blocks containing 31 papers.

The first block is entitled “Prediction, perceived risk, and vulnerabilities” and contains papers dealing with biological and toxin weapons convention, misperceptions in preparing for biological attack and public perception and risk communication in regard to bioterrorism against animals and plants.

The second block is entitled “Current and historical realities” and contains papers dealing with the history of biological disasters of animal origin in North America, the eradication of African swine fever in Brazil, quantitative risk assessment case study, illegal introduction of rabbit haemorrhagic disease virus in New Zealand and risk of Rift Valley fever epidemic in Mecca, Saudi Arabia. The most informative is a review of recent unexpected animal disease events in Japan and Korea and the follow-up action taken.

The third block is entitled “Proactive responses: a description of existing tools for managing the threats of biological disaster” and contains a series of useful contributions such as: distinguishing between natural and unnatural outbreaks of animal diseases, the design and establishment of epidemiological surveillance system for high-risk diseases in developed countries, animal disease outbreak control and the use of crisis management tools, the National Incident Management System - a multi-agency approach to emergency response in the USA, disease prevention and preparedness for animal emergencies in the Middle East, use and abuse of mathematical models etc.

The fourth block is entitled “Planning for the future: where do we need to be in 20 years ?” and contains several papers such as that it is hard to predict the future - the evolving nature of threats and vulnerabilities, problems of investment in preventing and preparing for biological emergencies and disasters, social and economic costs of disaster versus cost of surveillance and response preparedness and finally the challenges and options for animal and public health services in the next two decades.

The most useful paper, bringing new very important data on the FMD panzootic and objective analysis of negative experience with mathematical modelling during UK FMD disaster in 2001, the most devastating one in the modern history, was written by Kitching, Thrusfield and Taylor. The paper is entitled “Use and abuse of mathematical models: an illustration from the 2001 foot and mouth disease epidemic in the United Kingdom”. Some self-explanatory quotations, serving as a very important lesson for the future, merit to be mentioned: “The official figure for the number of animals slaughtered was approximately 6.5 million, but when the total number of still-sucking lambs, calves and pigs that were slaughtered is included, the total could be as high as ten million. Approximately three million healthy animals were slaughtered to control the epidemic.! The financial cost of the FMD epidemic in the UK was over 12 billion US$, including US$ 4.5 billion in losses sustained by the leisure and tourist industry. However, the social cost could not be quantified. During the 2001 epidemic of FMD in the United Kingdom (UK), the traditional approach was supplemented by a culling policy driven by unvalidated predictive mathematical models. Their idea was to control the disease by culling in contiguous farms. That is fine if you are sitting in front of a computer screen in London. However, it is different on the ground. The results showed that automatic contiguous culling was unnecessary, and could be replaced by applying basic epidemiological principles to decide the risk of exposure to infection. The amount of slaughter that took place is not longer likely to be tolerated by the public. The public memory of the mounds of dead animals, funeral pyres and burial pits cannot be erased. The perceived merit of this action came from mathematical predictive models… used as guides to control the 2001 epidemic in the UK. It was carnage by computer ! This graphically exemplifies the isolation and abstraction of ‘armchair epidemiology’ ! The consequences following the recommendations of these models were severe: economically, in terms of cost to the country; socially, in terms of misery and even suicides among those involved in the slaughter programme; and scientifically, in the abuse of predictive models, and their possible ultimate adverse effect on disease control policy in the future. The utility of predictive models as tactical decision support tools is limited by the innate unpredictability of disease spread. A model constitutes a theory, and a predictive model is therefore only a theoretical projection. It is not necessary to be mathematically literate to appreciate that no model will produce the right output when fed by the wrong input. The UK experience provides a salutary warning of how models can be abused in the interests of scientific opportunism.”

This example demonstrated very dangerous harmfulness of the “armchair epidemiology” deviating the strategy and measures from the field reality and ignoring biological character of the epizootics and thus instead to help causing enormous losses. The mathematical modellers share great deal of the responsibility for the UK disaster. The same paper contains other very important data on the distances of FMD virus aerosol spreading and that infected pigs produce up to 3,000 times more aerosol virus than sheep or cattle.

The main purpose of this book is to raise the awareness of health policy makers of the importance of biological disaster of animal origin and to provide useful information on disease emergency experience and relevant actions of international organizations.

Prof. MVDr V. K o u b a , DrSc.

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Additional Note:

I.M. Mansley, A.I. Donaldson, M.V. Trusfield and N. Honhold: Destructive tension: mathematics versus experience – the progress and control of the 2001 foot and mouth disease epidemic in Great Britain. Rev. Sci. Tech. Off. Int. Epiz. 2011:. «.. A controversial novel policy requiring the slaughter of sheep within 3 km of premises on which disease had been confirmed (the 3km cull) commenced after the peak of infection spread, was untargeted and took several weeks to complete.»

Addendum from Book Review in Agricultura Tropica et Subtropica, 45/3, 80-81 (2), 2011

Models in the management of animal diseases, OIE Review scientific and technique, Vol. 30 (2), 2011

This publication of Office International of Epizootics (OIE) on 261 pages contains 22 papers edited by P. Willeberg from the Center for Animal Disease Modelling and Surveillance, School of Veterinary Medicine, University of California, Davis, USA. Names of the authors from USA appear 20 times, from Canada 13 times, from UK as well as from New Zealand and Netherlands 8 times, from Australia 6 times, from Denmark 5 times, etc. The most active author was C. Dubé from Canada involved in 5 contributions. The results of the 2007 OIE questionnaire on using models in contingency plans consisted in statistical processing of the answers on nine general questions without asking for the most important aspect - experience with practical application. All contributions, except for two, represent imaginative speculations isolated from practical reality. The basic fact is usually not taken into account, namely, that the infections are extremely complex non-quantifiable dynamic biological phenomena with almost infinite variability of their etiological agents as far as types, subtypes, strains, pathogenicity, virulence, tenacity, etc. Furthermore, the immense variability of influencing factors such as ecological, economic, social, human etc. is not taken into account either. Every case is different in time and place as well as in forms, course, ability and way of spreading etc. requiring different measures. Four papers are dedicated to foot and mouth disease: estimation of foot and mouth disease transmission parameters, foot and mouth disease model verification and sensitivity analysis of the New Zealand standard model of foot and mouth disease. The contribution entitled “Destructive tension: mathematics versus experience – the progress and control of the 2001 foot and mouth disease epidemic in Great Britain” is the most important one. Used mathematical model elaborated in New Zealand (without experience with this disease – never reported) contributed to the most catastrophic losses in the world veterinary history – about 10 million animals (including almost three million healthy animals slaughtered unnecessarily). It was carnage by computer! This paper represents for all the countries serious warning against the use of mathematical models for the management of animal health without previous testing to confirm their feasibility and effectiveness. Therefore, this contribution is extremely beneficial for avoiding similar situation in the future. Member country governments financing the OIE need information useful for the solution of their anti-epizootic problems. The published models of pure abstract nature are not ready for general practical application. The utility of mathematical models as tactical decision support tools is very limited by the innate unpredictability of disease spread.

Václav Kouba