2001년 영국의 구제역 발생 및 전파, 그리고 방역대책을 다룬 로얄 소사이어티의
2002년 보고서 전문

Infectious diseases in livestock

Scientific questions relating to the transmission,
prevention and control of epidemic outbreaks of
infectious disease in livestock in Great Britain

Contents

Summary and main recommendations vii
1 Overview 1
(a) Introduction 1
(b) Origins of this inquiry 2
(c) The public background and the possibilities 4
(d) The issues of ‘disease-free’ status 5
References 7
2 The modern livestock industry 9
(a) General situation 9
(b) Cattle 11
(c) Sheep 12
(d) Pigs 12
(e) Poultry (excluding eggs) 13
(f) Horses 14
(g) Fish farming 14
(h) Exports 15
References 16
3 Infectious diseases of livestock 17
(a) List A and List B diseases and definitions 17
(i) Foot-and-mouth disease 18
(ii) Classical swine fever (CSF) 26
(iii) African swine fever (ASF) 27
(iv) Avian influenza (AI) 27
(v) Newcastle disease 28
(vi) Blue tongue (BT) and African horse sickness (AHS) 29
(b) Diseases affecting the main livestock sectors 30
(i) Cattle 30
(ii) Sheep 31
(iii) Pigs 32
(iv) Poultry 33
(v) Horses 33
(vi) Fish farming 35
(c) Conclusion and recommendations 35
References 36
4 The trading dimension 39
(a) The world trading framework and the role of the OIE and its reference laboratories 39
(b) Trading and ‘disease-free status’ 40
(c) Trading within the EU 40
5 Surveillance, biosecurity and livestock management 43
(a) Introduction 43
(b) The global threat 43
(i) FMD 44
(ii) Bluetongue virus 45
(c) International surveillance 45
(d) Imports: the rules for trade 46
(e) Imports: policing the frontiers 48
(f) National surveillance 49
(i) Responding to early warnings 49
(ii) Reducing animal movements 49
(iii) Surveillance on the farm: the farmer–veterinarian linkage 51
(iv) Reducing risk on the farm: biosecurity and livestock management practices 52
(g) Recommendations 54
References 55
6 Epidemiology, data and modelling 57
(a) Introduction 57
(b) Why are some outbreaks difficult to control? 58
(i) How do outbreaks grow and then decline? 58
(ii) The problem of early infectivity 59
(iii) The benefits of decisive interventions 61
(c) Management and analysis of the data 62
(i) What can analyses offer? 62
(ii) Data quality and data management 63
(d) Data requirements 64
(i) Case finding and contact tracing 64
(ii) Livestock demography and farm geography 64
(iii) Epidemiology of transmission 65
(iv) Control options, and their likely impact and logistical requirements 65
(e) Mathematical modelling 66
(i) Types of model 66
(ii) Developing and testing models 70
(iii) Use of models before the next outbreak 70
(iv) Use of models during an outbreak 70
(f) Future requirements 71
References 73
7 Diagnosis 75
(a) Introduction 75
(b) The general principles 75
(c) The specific diagnosis of foot-and-mouth disease (FMD) 77
(i) Clinical diagnosis in the field 78
(ii) Laboratory diagnosis of the index case 78
(iii) Diagnosis during an outbreak 79
(iv) Surveillance after an outbreak 79
(d) Improved diagnostics and their potential application to the decentralisation of diagnosis 79
(i) The need for speed 79
(ii) PCR methods for the detection of nucleic acid 80
(iii) Detection of viral antigen and antibody by ELISA 81
(e) The prospect of novel approaches applied to diagnosis and disease control 81
(i) Biosensors—general 82
(ii) Biosensors and FMD 82
(f) Maintaining a state of preparedness 82
(g) Integrating diagnosis to rapid response 83
(h) General conclusions on diagnosis of other List A diseases 83
(i) Recommendations 84
References 84
8 Vaccination 87
(a) Introduction 87
(b) Elimination of infectious diseases by vaccines 87
(i) Experience of routine vaccination for FMD 88
(ii) The immune responses to viral infections 90
(iii) The immune response to viral vaccines 91
(iv) The economics of routine vaccination 93
(v) Key design features of vaccines 94
(c) Improving routine vaccines for FMD 96
(d) Emergency vaccination against FMD 97
(i) The carrier state 97
(ii) Are carrier animals infectious? 98
(iii) Discriminating between vaccinated and infected animals 99
(iv) Efficacy of emergency vaccines in an outbreak 100
(v) The role of vaccine banks 101
(vi) Exit strategies 102
(e) Vaccines against other exotic viral diseases of livestock 102
(i) High-risk diseases 102
(ii) Medium-risk diseases 104
(iii) Low-risk diseases 104
(f) Recommendations 105
References 105
9 Dealing with an outbreak: control measures and relevant wider issues 111
(a) Introduction and background 111
(i) Ethics and welfare issues 111
(ii) Environmental issues 112
(iii) Human health considerations 113
(iv) Resources 113
(v) Permanent standstill periods for all livestock 113
(vi) Increased levels of surveillance on farm 113
(vii) Technical input to the control of disease 114
(b) Key control measures that can be applied during an outbreak 115
(i) Enhanced biosecurity 115
(ii) Culling 116
(iii) Emergency vaccination 118
(iv) Special arrangements—zoos and rare breeds 121
(v) Requirements at end of outbreak 122
(c) Control of other diseases 122
Contol measures 123
(d) Contingency planning 123
Development of the control policy component within the contingency plan 124
(e) Recommendations 124
References 125
10 Research and development, education and training 131
(a) Research and development 131
(i) Introduction 131
(ii) Animal disease research in Britain 131
(iii) Current provision and issues 132
(iv) Resources 135
(b) Education and training 136
(i) Farmers and livestock keepers 136
(ii) Undergraduate veterinary education 136
(iii) Continuing professional development 137
References 139
Annex A: Terms of reference 141
Annex B: Conduct of the Inquiry 143
Annex C: List of those who gave evidence 147
Annex D: Glossary 157
Figures
2.1 Maps of livestock distributions in England 9
2.2 Land use in the UK 10
2.3 Value of UK livestock production (£ millions) in 1996 and 2000 10
2.4 Analysis of UK livestock holdings by size and total area 11
2.5 Numbers of livestock holdings, animals and average herd of flock size in the UK 11
2.6 UK livestock numbers in 1967 and 2000 11
2.7 Exports of livestock and livestock products from the UK (£ millions) 15
3.1 The 15 List A diseases and their incidences in the UK 17
3.2 Other notifiable diseases in the UK (excluding those of fish) 18
3.3 Maximum virus excretion/secretion routes in cattle 20
3.4 Most likely method of spread of FMD in each geographic area 21
3.5 Airborne spread of the FMD virus during the 1967–68 epidemic 22
3.6 Movement of FMD-infected animals before 23 February 2001, and locations of implicated
markets, abattoirs and dealers 23
4.1 Levels of ‘disease-free status’ for foot and mouth diseases (FMD) 41
4.2 General conditions for regaining disease-free status after an outbreak of foot-and-mouth disease 41
4.3 Conditions for regaining disease-free status after an outbreak of foot-and-mouth disease. 41
5.1 The spread of Type O pan-Asia strain of FMD virus since 1990 44
5.2 Probability of purchasing one or more Mycobacterium paratuberculosis infected cattle, by number
and source of introduced cattle 54
5.3 Probability of purchasing one or more cows persistently infected with bovine viral diarrhoea,
by number and source of introduced cows 54
6.1 Local conditions determine the impact of a control policy 59
6.2 Development of virus in blood and breath relative to the appearance of clinical signs for a
typical FMD infection in a single cow 59
6.3 The development through time of the number of secondary infections generated from
one infected farm 60
6.4 Early and apparently harsh interventions can save animal lives in the long run 61
6.5 R0 map from the 2001 FMD epidemic. 63
6.6 Case histories of the use of models of infectious disease for understanding, planning and predicting 67
6.7 Some uses of models in understanding disease 69
7.1 Methods for virus detection used in human and veterinary medicine 76
8.1 Examples of successful human and veterinary vaccines 89
8.2 Estimated annual costs (£ millions) of routine FMD vaccination in the UK 94
8.3 Exotic viral diseases that pose a threat to UK livestock 103
9.1 The technical input to the decision-making process 115
9.2 Criteria to be taken into account when considering emergency vaccination 120
9.3 Biological properties of other List A viruses threatening the UK 126
10.1 Average number of research publications per year on livestock diseases during 1991–2001 134
10.2 Postgraduate qualifications in selected veterinary subjects, as at 31 December 2001 137