Risk analysis is something that people do intuitively in their everyday lives and in their professional work. Only recently has it developed into a more formal discipline that is being used increasingly in many fields. In animal health it has perhaps been most widely applied in import control and quarantine. Quarantine risk analyses are used for helping to decide the most appropriate health conditions for imported animals and animal products and for strategies for quarantine operations.
Risk analysis is a tool that can also be used to very good advantage for animal disease emergency preparedness planning. In this context, it is most readily applied to preparedness planning for the occurrence of transboundary animal diseases (or exotic strains of endemic disease agents) and it will be described for this purpose here. However, there is no reason why risk analysis annot be applied to other animal health emergency planning.
Risk analysis comprises four components: risk identification, risk assessment, risk mitigation or management and risk communication.
Risk identification
In this first component, the risks of untoward events or things that may happen in the future are first identified and then described. In the context of animal health emergencies, this would include identification of all high threat diseases (exotic or otherwise); the factors that may change the level of risk (e.g. new serotypes or biotypes, or changing epidemiological or livestock husbandry patterns); and factors that may impinge on the capacity of the national animal health services to respond effectively to the disease threats.
Risk assessment
The likelihood of these risks occurring is then estimated. The potential consequences of the risks if they occur are also evaluated and used to modify the assessment of the risk. For example, an exotic disease that had a high risk of entry to a country, but only a low risk of establishment or trivial potential socio-economic consequences for the country, would only get a low overall score in a risk assessment. Conversely, a disease assessed as having a low risk of introduction but significant consequences if introduced would be rated more highly.
Risks can be assessed in a quantified, semi-quantified or qualitative way. It is inherently very difficult to quantify (or actually ascribe probability percentages to) risks in many biological systems because of the lack of historical precedents and serious gaps in available biological data. Risks should be quantified as far as is practicable. If this cannot be done, qualitative risk assessments are recommended for exotic diseases. Risks can be described as extreme, high, medium and low, or preferably by a simple scoring system, for example, 1-5 for both the level of risk and for the degree of potential consequences. This will help to establish a priority ranking for identified risks, and provide a solid platform for contingency planning.
Risk mitigation or management
This is the process of identifying, documenting and implementing measures to reduce identified risks and their consequences. The risks posed by FMD can never be completely eliminated. The aim is to adopt procedures that will reduce the level of risk to what is deemed to be an acceptable level.
This manual could be regarded as providing the risk management framework for FMD contingency planning.
Risk communication
This is the process of exchange of information and opinions on risk between risk analysts and stakeholders. Stakeholders in this context include all those who could be affected by the consequences of the risks (i.e. everyone from farmers to politicians). It is important that risk assessment and risk management strategies be fully discussed with stakeholders so that they feel comfortable that no unnecessary risks are being taken and the risk management costs are a worthwhile "insurance policy".
To ensure ownership of decisions, risk analysts and decision-makers should consult with stakeholders throughout the whole process of risk analysis so that the risk management strategies address stakeholder concerns, and decisions are well understood and broadly supported.
The risk assessment component is best carried out by the Epidemiological Unit in the National Veterinary Service as part of the national early warning system for transboundary animal diseases (TADs) and other emergency diseases. Risk management and risk communication are tasks for everyone, but should be coordinated by the chief veterinary officer (CVO).
It should be remembered that risks do not remain static. They will change with factors such as evolution and spread of epidemic livestock diseases internationally; emergence of new diseases; changing international trading patterns in the country; and new scientific knowledge and technology. Risk analysis should therefore not be regarded as a one-off activity but be repeated and updated regularly.
As described above, risk assessment consists of identifying the risks, assessing the likelihood of their occurrence and modifying/ reducing them where possible by an evaluation of their potential consequences.
The international status and evolution of outbreaks of FMD (and other important TADs) as well as the latest scientific findings should be constantly monitored. This should be a routine function of the Epidemiological Unit of the National Veterinary Service. Apart from the scientific literature, the most valuable source of information is the International Office of Epizootics (OIE), for example through its weekly disease reports, the annual OIE World Animal Health and through the OIE Handistatus database. Disease intelligence is also available from FAO, particularly in the EMPRES Transboundary Animal Diseases Bulletin, which is published quarterly (and is also available on the Internet at www.fao.org/empres). The Program for Monitoring Emerging Diseases (ProMED), an Internet server and mailing service, currently provides a useful forum for rapid dissemination of official and unofficial information on animal, plant and human disease occurrences around the world. Information may also be obtained from designated OIE and FAO experts and reference laboratories and from regional groups established to coordinate FMD control such as the European Commission for the Control of Foot-and-Mouth Disease (EUFMD), the Pan American Foot-and-Mouth Disease Center (Panaftosa) and the Southeast Asian Foot-and Mouth Disease Campaign (SEAFMD).
Having identified and listed the exotic disease threats, the next step is to assess the seriousness of the threat of entry of each disease to the country[1] and the routes and mechanisms by which the disease may enter. Relevant questions to be answered for FMD include the following:
What is the current geographic distribution and incidence of FMD, including that of its serotypes, around the world?
Is the distribution fairly static or has there been a recent history of spread to new countries, regions or continents (for example the international spread of the Pan-Asia strain of type O during the period 1990-2001)?
Have any new antigenic subtypes emerged that may threaten even countries that routinely vaccinate against the disease?
How close is the disease? What is the status of neighbouring countries, not only in respect to the known presence of FMD, but also the level of confidence in their veterinary services to be able to detect and control outbreaks of the disease?
If FMD is present in neighbouring countries, where are the nearest outbreaks to shared borders?
Are there any feral or wildlife animal populations in the country that are susceptible to FMD and that may introduce the disease (e.g. through natural migrations) and/or act as a reservoir for the disease?
Is there a past history of introduction of FMD to the country? Is it possible that it is still present in undetected endemic pockets of infection in domestic, feral or wild ruminant animals and pigs?
How is the disease likely to be spread in the country? What would be the relative roles of live animals and their movements; fomites; meat or other animal products; animal genetic material; windborne spread, etc. in transmitting the aetiological agent?
Are there significant imports of potential risk animal species, meat products or other materials for FMD? Do they come from endemic regions? Do quarantine import protocols conform to OIE standards? How secure are import quarantine procedures?
How secure are barrier and border import controls/quarantine procedures to prevent unlawful entry of risk materials for FMD?
Is swill feeding of pigs a common practice in the country? Are there adequate safeguards to make this practice safe?
Are there smuggling, unofficial livestock movements, transhumance or nomadism practices that would constitute a risk for the entry of FMD? In particular, is there political instability/civil unrest in neighbouring countries that might result in major movements of people and movement or abandonment of livestock?
Where are infected animals likely to cross the border and where are the main livestock trading routes from these areas?
The next step is to evaluate how serious the socio-economic consequences might be if the disease occurs. There are a number of questions to be answered:
Is the disease likely to become established in the country? Are there susceptible livestock host populations?
Is the disease likely to become established in feral animal or wildlife populations?
Will it be difficult to recognize the disease quickly in different parts of the country?
How big are the populations of cattle, pigs, sheep and goats in the country? What are the livestock management and trading systems? How important are those livestock industries to the national economy? What is their importance in satisfying nutritional (food security) and other community needs?
How are these livestock industries structured within the country? Are there large commercial and/or intensive production industries or do they consist of smallholder/village production or extensive pastoral systems? Is production concentrated in just a few areas of the country?
How serious will the production losses be from the disease? Will food security be threatened? What will be the socioeconomic consequences?
Is there an actual or potential export trade in livestock or livestock products? If so, how important is this export trade for the national economy? What would be the likely reaction of importing countries if FMD were found in the country? What would be the socio-economic consequences, both at a local and national level, of the loss of export trade for an extended period?
What are the likely consequences on internal trade in livestock and livestock products?
Are there populations of cattle, water buffaloes, pigs, sheep or goats that are poorly controlled and allowed to roam freely or are feral, and that may constitute reservoirs of FMD infection that are difficult to control?
How difficult and costly will the disease be to control and eradicate? Can it be eradicated? All resources including both direct and indirect costs should be considered.
Are there likely to be adequate trained human resources and physical and financial resources available to mount an effective response against an incursion of the disease?
By addressing these questions and issues it will be possible to build up a risk profile for FMD, uncover weaknesses and make judgements on the magnitude of the risk presented by the disease in qualitative, if not quantitative, terms. Most important, it will be possible to get an idea of how FMD ranks in relation to other high-priority risk diseases, and what resources need to be devoted to preparedness for FMD in comparison with other diseases. Possible pressure points for entry of the disease can be ascertained, showing where preventive and disease surveillance activities need to be strengthened. Finally, it should indicate whether the veterinary services and contingency planning need to be strengthened to cope with FMD.
It should be recognized that many risk factors will vary over time, which is one of the many critical reasons why this manual needs to be periodically reviewed.
The type of risk assessment described will help to:
determine where FMD ranks in the priority list of serious disease threats for the country and what level of resources should be devoted to preparing for it in comparison with other diseases;
determine how and where quarantine protocols and procedures need to be strengthened;
determine how laboratory diagnostic capabilities need to be strengthened;
plan training courses for veterinary staff and farmer awareness and publicity campaigns;
determine how and where active disease surveillance needs to be strengthened;
plan disease response strategies.
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[1] Risk assessment can also be
conducted with zones or regions of a country that have different animal health
status. The principles are generally the same and require very fine knowledge of
one's animal health status, marketing infrastructure, transportation and
regulatory capabilities. |
