An evaluation of scrapie surveillance in the United States

Animal health surveillance systems should reflect national disease control priorities and promote the best use of public resources by maximizing effectiveness and efficiency. A surveillance system should be routinely evaluated to assess the degree to which the system accomplishes these goals, fulfills its stated objectives, and meets accepted surveillance standards. In the United States, there are a number of disparate endemic disease surveillance and eradication programs. The National Animal Health Surveillance System is a federal initiative designed to combine animal health surveillance and monitoring activities into a comprehensive and coordinated system. A protocol has been developed to facilitate the evaluation of animal health surveillance systems and investigate opportunities for coordination between the different surveillance and eradication programs. The evaluation protocol was based largely on protocols developed for public health but adapted for the specific needs and goals of animal health surveillance. The evaluation process was designed to identify program strengths and areas for improvement and facilitate the system's adaptability to changing situations. The evaluation protocol was applied to the scrapie surveillance system in the United States; scrapie surveillance was found to be an important part of surveillance for transmissible spongiform encephalopathies. Results from the evaluation of sensitivity, sampling methods and representativeness are presented.     

National animal health surveillance: Return on investment

A weighted benefit-cost analysis (BCA) supports prioritization of animal health surveillance activities to safeguard animal agriculture industries and reduce the impact of disease on the national economy. We propose to determine the value of investment in surveillance by assessing benefits from: avoiding disease incursion and expansion modified by the probability of occurrence of the disease event, the sensitivity of systems to detect it, and the degree to which we can mitigate disease impact when detected. The weighted benefit-cost ratio is the modified value of surveillance as laid out above divided by the cost of surveillance. We propose flexible, stream-based surveillance that capitalizes on combining multiple streams of information from both specific pathogen based and non-pathogen based surveillance. This stream-based type of system provides high value with lower costs and will provide a high return for the funds invested in animal health surveillance.     

The DairyCHAMP program: a computerised recording system for dairy herds

The DairyCHAMP program is an animal health and management software program that helps daily animal management, herd performance monitoring and problem analysis. Data entry to the program uses a data dictionary and includes an error-checking system that ensures the consistency and appropriateness of data entered. DairyCHAMP performs health management functions, provides a convenient user interface, ensures uniform data across farms by using a standard data dictionary, can be fully integrated with decision-making software programs like DairyORACLE, and is flexible enough to be useful for many types of dairy facilities. Data are entered via a menu-based system. Animal events are organised around reproduction and lactation cycles and health records. Farm records include inventories for drug, feed and semen. Farm parameters can be established which customize the program for an individual farm. The database system is an integration of three schemas: the individual user's view, the community view and the storage system. The individual user's view must be easy to use, while the storage system must be compact enough to fit within the disc storage space on a microcomputer. This conflict requires a translation from one schema to another. The DairyCHAMP program accomplishes this through a coding system which assigns a code number to each event. The program can add synonyms to this event dictionary by assigning the same code number to the synonym the user chooses. The DairyCHAMP program provides access to the large amounts of data required to aid in daily animal management, allow performance monitoring and analyse problems. Its highly integrated system is efficient and easy to use and maintain.     

Animal-based national surveillance for zoonotic disease: quality, limitations, and implications of a model system for monitoring rabies

Surveillance for zoonotic diseases among wildlife is a research and public health challenge. The inherent limitations posed by the requisite human–animal interactions are often undefined and underappreciated. The national surveillance system for animal rabies in the United States was examined as a model system; reporting of animal rabies is legally mandated, each case of rabies is laboratory confirmed, and data have been consistently collected for more than 50 years. Factors influencing the monthly counts of animal rabies tests reported during 1992–2001 were assessed by univariate and multivariable regression methods. The suitability of passively collected surveillance data for determining the presence or absence of the raccoon-associated variant of rabies within states and within individual counties was assessed by determining critical threshold values from the regression analyses. The size of the human population and total expenditures within a county accounted for 72% and 67%, respectively, of the variance in testing. The annual median number of rabies tests performed was seven for counties without rabies, 22 for counties with non-raccoon rabies, and 34 for counties with raccoon rabies. Active surveillance may be required in locales with sparse human populations when a high degree of confidence in the status of rabies is required.     

The Canadian Cooperative Wildlife Health Centre and surveillance of wild animal diseases in Canada.

The Canadian Cooperative Wildlife Health Centre (CCWHC) was established in 1992 as an organization among Canada's 4 veterinary colleges, with a mandate to apply veterinary medicine to wildlife management and conservation in Canada. A major function of the CCWHC is nation-wide surveillance of wild animal diseases. Disease surveillance is conceived as consisting of 4 different activities: detection, diagnosis, information management, and use of information. In the CCWHC surveillance program, detection of disease is carried out by a wide range of professional and avocational field personnel, and much effort is expended to stimulate and support this activity. Diagnosis is done by personnel of provincial and federal veterinary laboratories and the CCWHC. Information management is achieved through a national database of wildlife disease incidents developed and maintained by the CCWHC. Use of information is enabled through established channels for distribution of information derived from the surveillance program to persons responsible for wildlife programs and policies, and to the public. There has been a high demand for the services of the CCWHC since its establishment. The CCWHC responds to approximately 2000 requests for information annually, distributes its newsletter to over 1700 recipients, examines approximately 1200 wild animal submissions each year, and has accumulated records of over 5000 disease incidents in its database. Technical information from the CCWHC has benefited federal, provincial/territorial, and nongovernment wildlife agencies; endangered species recovery programs; federal and provincial veterinary services; and federal and provincial public health programs.     

The Animal and Plant Health Inspection Service (APHIS) brucellosis eradication program in the United States

Efforts to eradicate brucellosis caused by Brucella abortus in the United States began in 1934 as part of an economic recovery program to reduce the cattle population because of the Great Depression and concurrent severe drought conditions. A number of states saw this as an opportunity to reduce the level of brucellosis, which was the most significant livestock disease problem in the US at the time. In 1934 and 1935, the reactor rate in adult cattle tested was 11.5%. In 1954, the magnitude of the brucellosis problem in the United States in terms of economics to the cattle industry and human health prompted Congress to appropriate funds for a comprehensive national effort to eradicate brucellosis. The brucellosis eradication program was designed as a cooperative effort between the federal government, the states, and livestock producers. As the science and technology of brucellosis has developed over the years through research and experience, the eradication program has been modified many times.

As of 31 December 2000, there were no affected cattle herds in the United States. This was the first time in the history of the brucellosis program that the United States had no known brucellosis affected herds. However, brucellosis has a variable, sometimes quite lengthy incubation period, so it is expected that additional affected herds will be disclosed. It is likely that additional affected herds will be disclosed before brucellosis is finally eradicated from cattle. Animal health officials remain prepared to aggressively pursue any newly disclosed affected herds to eliminate the disease as quickly as possible.

The State-Federal Brucellosis Eradication Program has made tremendous progress since its inception. In an eradication program, it is critically important to recognize that, despite all the tools that are available to eliminate the disease, an effective surveillance system is the critical first step that must be in place in order to be successful. It is imperative, not only to be able to find the disease and eliminate it, but to find it before it spreads to susceptible herds. When brucellosis can be identified, contained, and eliminated before spread occurs, eradication can be achieved.     

Animal health surveillance: navigation amidst the flotsam of human frailty and fiscal inertia

National veterinary services monitor endemic, emerging and exotic disease situations. They intervene when epidemic tendencies demand. They unravel complex disease situations. They do so as monopolies, in environments of political influence and budgetary restraint. When human, animal health and trade protection dictate, they design import or domestic disease control programs. As much as 80% of program expenditures are on surveillance. Their initiatives are scrutinized by treasuries from which they seek funding, industries from which they seek collaboration and trading partners from whom they seek recognition. In democracies, surveillance and control programs are often the products of a complicated consultative process. It involves individuals who have both a commitment to improving an existing animal health situation and access to the required resources. The generations that designed traditionally risk-averse national surveillance and control programs have given way to a new one which is more epidemiologically informed. Their successors design programs bearing epidemiologically based improvements. The transition, however, has not been overwhelmingly welcomed. Expenditures on surveillance are tolerated out of fear during outbreaks of foreign or re-emergence of indigenous disease. Between epidemics, they decline at the hands of producers' unwillingness and budgetary restraint. Human nature responds to the high cost of surveillance in forms ranging from na?veté through to conspiracy. While legislation cannot subdue such human frailty, several other opportunities exist. Education can remove the majority of problems caused by ignorance, leaving the minority that arise intentionally. Technology decreases the high cost of testing which tempts individuals to cut corners. International standards assist National Veterinary Services to overcome domestic resistance.     

Economic Assessment of Zoonoses Surveillance in a ‘One Health’ Context: A Conceptual Framework

Collaboration between animal and public health sectors has been highlighted as a means to improve the management of zoonotic threats. This includes surveillance systems for zoonoses, where enhanced cross‐sectoral integration and sharing of information are seen as key to improved public health outcomes. Yet, there is a lack of evidence on the economic returns of such collaboration, particularly in the development and implementation of surveillance programmes. The economic assessment of surveillance in this context needs to be underpinned by the understanding of the links between zoonotic disease surveillance in animal populations and the wider public health disease mitigation process and how these relations impact on the costs and benefits of the surveillance activities. This study presents a conceptual framework of these links as a basis for the economic assessment of cross‐sectoral zoonoses surveillance with the aim of supporting the prioritization of resource allocation to surveillance. In the proposed framework, monetary, non‐monetary and intermediate or intangible cost components and benefit streams of three conceptually distinct stages of zoonotic disease mitigation are identified. In each stage, as the final disease mitigation objective varies so does the use of surveillance information generated in the animal populations for public health decision‐making. Consequently, the associated cost components and benefit streams also change. Building on the proposed framework and taking into account these links, practical steps for its application are presented and future challenges are discussed.     

Veterinary syndromic surveillance: Current initiatives and potential for development

This paper reviews recent progress in the development of syndromic surveillance systems for veterinary medicine. Peer-reviewed and grey literature were searched in order to identify surveillance systems that explicitly address outbreak detection based on systematic monitoring of animal population data, in any phase of implementation. The review found that developments in veterinary syndromic surveillance are focused not only on animal health, but also on the use of animals as sentinels for public health, representing a further step towards One Medicine. The main sources of information are clinical data from practitioners and laboratory data, but a number of other sources are being explored. Due to limitations inherent in the way data on animal health is collected, the development of veterinary syndromic surveillance initially focused on animal health data collection strategies, analyzing historical data for their potential to support systematic monitoring, or solving problems of data classification and integration. Systems based on passive notification or data transfers are now dealing with sustainability issues. Given the ongoing barriers in availability of data, diagnostic laboratories appear to provide the most readily available data sources for syndromic surveillance in animal health. As the bottlenecks around data source availability are overcome, the next challenge is consolidating data standards for data classification, promoting the integration of different animal health surveillance systems, and also the integration to public health surveillance. Moreover, the outputs of systems for systematic monitoring of animal health data must be directly connected to real-time decision support systems which are increasingly being used for disease management and control.     

Yersinia pestis: examining wildlife plague surveillance in China and the USA

Plague is a zoonotic disease caused by the bacterium Yersinia pestis Lehmann and Neumann, 1896. Although it is essentially a disease of rodents, plague can also be transmitted to people. Historically, plague has caused massive morbidity and mortality events in human populations, and has recently been classified as a reemerging disease in many parts of the world. This public health threat has led many countries to set up wild and domestic animal surveillance programs in an attempt to monitor plague activity that could potentially spill over into human populations. Both China and the USA have plague surveillance programs in place, but the disease dynamics differ in each country. We present data on plague seroprevalence in wildlife and review different approaches for plague surveillance in the 2 countries. The need to better comprehend plague dynamics, combined with the fact that there are still several thousand human plague cases per year, make well-designed wildlife surveillance programs a critical part of both understanding plague risks to humans and preventing disease outbreaks in the future.     

The Ontario Animal Health Network: enhancing disease surveillance and information sharing through integrative data sharing and management

The Ontario Animal Health Network (OAHN) is an innovative disease surveillance program created to enhance preparedness, early detection, and response to animal disease in Ontario. Laboratory data and, where available, abattoir condemnation data and clinical observations submitted by practicing veterinarians form the core of regular discussions of the species-sector networks. Each network is comprised of government veterinarians or specialists, epidemiologists, pathologists, university species specialists, industry stakeholders, and practicing veterinarians, as appropriate. Laboratorians provide data for diseases of interest as determined by the individual network, and network members provide analysis and context for the large volume of information. Networks assess data for disease trends and the emergence of new clinical syndromes, as well as generate information on the health and disease status for each sector in the province. Members assess data validity and quality, which may be limited by multiple factors. Interpretation of laboratory tests and antimicrobial resistance trends without available clinical histories can be challenging. Extrapolation of disease incidence or risk from laboratory submissions to broader species populations must be done with caution. Disease information is communicated in a variety of media to inform veterinary and agricultural sectors of regional disease risks. Through network engagement, information gaps have been addressed, such as educational initiatives to improve sample submissions and enhance diagnostic outcomes, and the development of applied network-driven research. These diverse network initiatives, developed after careful assessment of laboratory and other data, demonstrate that novel approaches to analysis and interpretation can result in a variety of disease risk mitigation actions.     

Institutional training programs for research personnel conducted by laboratory-animal veterinarians

Research institutions are required by federal law and national standards to ensure that individuals involved in animal research are appropriately trained in techniques and procedures used on animals. Meeting these requirements necessitates the support of institutional authorities; policies for the documentation and enforcement of training; resources to support and provide training programs; and high-quality, effective educational material. Because of their expertise, laboratory-animal veterinarians play an essential role in the design, implementation, and provision of educational programs for faculty, staff, and students in biomedical research. At large research institutions, provision of a training program for animal care and use personnel can be challenging because of the animal-research enterprise's size and scope. At the University of Michigan (UM), approximately 3,500 individuals have direct contact with animals used in research. We describe a comprehensive educational program for animal care and use personnel designed and provided by laboratory-animal veterinarians at UM and discuss the challenges associated with its implementation.     

A model (BSurvE) for evaluating national surveillance programs for bovine spongiform encephalopathy

Our BSurvE spreadsheet model estimates the BSE prevalence in a national cattle population, and can be used to evaluate and compare alternative strategies for a national surveillance program. Each individual surveillance test has a point value (based on demographic and epidemiological information) that reflects the likelihood of detecting BSE in an animal of a given age leaving the population via the stated surveillance stream. A target sum point value for the country is calculated according to a user-defined design prevalence and confidence level, the number of cases detected in animals born after the selected starting date and the national adult-herd size. Surveillance tests carried out on different sub-populations of animals are ranked according to the number of points gained per unit cost, and the results can be used in designing alternative surveillance programs.     

Animal health surveillance applications: The interaction of science and management

Animal health surveillance is an ever-evolving activity, since health- and risk-related policy and management decisions need to be backed by the best available scientific evidence and methodology. International organizations, trade partners, politicians, media and the public expect fast, understandable, up-to-date presentation and valid interpretation of animal disease data to support and document proper animal health management - in crises as well as in routine control applications. The delivery and application of surveillance information need to be further developed and optimized, and epidemiologists, risk managers, administrators and policy makers need to work together in order to secure progress. Promising new developments in areas such as risk-based surveillance, spatial presentation and analysis, and genomic epidemiology will be mentioned. Limitations and areas in need of further progress will be underlined, such as the general lack of a wide and open exchange of international animal disease surveillance data. During my more than 30 year career as a professor of Veterinary Epidemiology I had the good fortune of working in challenging environments with different eminent colleagues in different countries on a variety of animal health surveillance issues. My career change from professor to Chief Veterinary Officer (CVO) - "from science to application" - was caused by my desire to see for myself if and how well epidemiology would actually work to solve real-life problems as I had been telling my students for years that it would. Fortunately it worked for me! The job of a CVO is not that different from that of a professor of Veterinary Epidemiology; the underlying professional principles are the same. Every day I had to work from science, and base decisions and discussions on documented evidence - although sometimes the evidence was incomplete or data were simply lacking. A basic understanding of surveillance methodology is very useful for a CVO, since it provides a sound working platform not only for dealing with immediate questions when new or emerging disease situations arise, but also for more long-term activities, such as policy development, contingency planning and trade negotiations. Animal health issues, which emerged during my eight years as a CVO in Denmark from 1999 to 2007, will be used as examples, including BSE, FMD, HPAI and Trichinella testing. Emphasis will be placed on how science-based surveillance methodology and tools were developed, applied and documented.     

Is dietary choice important to animal welfare?

Scientific interest in farm animal welfare has grown rapidly in recent years because consumers increasingly demand that farm animals are reared, transported, and slaughtered in a humane way. Additionally, nutrition emerges as an important aspect of welfare since in most codes of recommendations for the welfare of animals, adequate nutrition is one of the primary requirements to be satisfied. We submit that in many cases domestic animals are provided with diets that, even when abundant and nutritious, are not necessarily adequate to foster the welfare of animals. The monotonous diets fed in confinement (total mixed rations) and on pasture (monocultures) often contain excesses of nutrients, nutrient imbalances, and toxins that adversely influence animal welfare. How much of any food an animal can eat will depend on the other foods it consumes, because at the biochemical level, nutrients and toxins interact one with another—nutrients with nutrients, nutrients with toxins, and toxins with toxins. Food intake and preference also depend on differences in how individual animals are built morphologically and how they function physiologically, and marked variation is common even among closely related animals relative to the needs for nutrients and tolerance to toxins. An integral part of an animal's ability to meet its particular nutritional requirements and consume substances that improve health depends on having a variety of foods available so each animal can select a diet that best meets its homeostatic needs. Food choice may also offer animals a means to cope with toxins, as certain food combinations have the potential to ameliorate the negative effects of toxins. We suggest that the availability of alternatives may not only contribute to maintain homeostasis but also reduce levels of stress. Thus, food choice is necessary for individual animals to have freedom to express their normal behaviors. We contend this freedom enables the uniqueness of individuals to be manifest, thereby promoting animal welfare and performance and increasing profitability of the people who manage animals.     

Technical and economic evaluation method for use in improving infectious animal disease surveillance networks

With hope of improving the increasing number of epidemiological surveillance networks for animal diseases set up in recent years, a qualitative and quantitative technical and economic evaluation tool was developed and then applied to three epidemiological surveillance networks: RENESA (a French surveillance network for salmonella and mycoplasma contamination in poultry production units subject to official sanitary controls), the French Foot and Mouth Disease Epidemiovigilance Network and REPIMAT (the epidemiological surveillance network in Chad for major cattle diseases). We identified critical points in epidemiological surveillance networks using a modified version of the hazard analysis: critical control point (HACCP) method. An evaluation grid was then developed and validated by experts who were consulted in accordance with the Delphi method. A questionnaire to collect the information required for the evaluation and a scoring guide were then designed. Our evaluation procedure also included a calculation of the annual operating costs for two of the three networks studied. On the basis of the detailed results of the technical and economic evaluation, we formulated specific suggestions for improving the networks. The cost of implementing these proposals was calculated. We then simulated the effects of implementing each of the proposed improvements and a new global evaluation score was determined for each network. The 'cost per point' of each improvement was then calculated and discussed. This tool for the technical and economic evaluation of epidemiological surveillance networks for animal diseases is proposed so that it may be tested on a far wider scale and eventually be used in improving the functioning of such networks and for risk analysis in international trade.     

Syndromic surveillance using laboratory test requests: A practical guide informed by experience with two systems

Syndromic surveillance systems can enhance early disease warning, endemic disease monitoring, or help to accumulate proof of disease freedom. In order to provide immediate feedback to achieve these goals, the health data sources scanned should be acquired continuously, in an automated fashion, and should be stored electronically. Recognizing that data from diagnostic test requests often meet these requirements, two systems designed to automatically extract surveillance information from animal laboratory databases have been developed and are described in this paper. These systems are designed to contribute to early disease detection, as well as the timely management of epidemiological information, in a province of Canada and in Sweden, the areas served by the diagnostic laboratories concerned. Classifying in-coming requests into syndromes, the first step, was the most time-consuming and the least portable step between the two systems. The remaining steps were more easily adjusted from one system to implementation in the other. These steps included: retrospective evaluation of data to create baseline profiles following the removal of excessive noise and aberrations; the identification of temporal effects; prospective evaluation of detection algorithms; and finally real-time monitoring and implementation. Building upon the institutions’ existing data management software, all steps to use those data for the purposes of syndromic surveillance were set up using open source software; as a result this approach could be readily adopted by other institutions. Relatively straight-forward development and maintenance is expected to lead to the incorporation of these systems into each institution's surveillance processes, becoming an indispensable tool for diagnosticians and epidemiologists, as well as stimulating further technical development of such systems.     

Policy-driven development of cost-effective, risk-based surveillance strategies

Animal health and residue surveillance verifies the good health status of the animal population, thereby supporting international free trade of animals and animal products. However, active surveillance is costly and time-consuming. The development of cost-effective tools for animal health and food hazard surveillance is therefore a priority for decision-makers in the field of veterinary public health. The assumption of this paper is that outcome-based formulation of standards, legislation leaving room for risk-based approaches and close collaboration and a mutual understanding and exchange between scientists and policy makers are essential for cost-effective surveillance. We illustrate this using the following examples: (i) a risk-based sample size calculation for surveys to substantiate freedom from diseases/infection, (ii) a cost-effective national surveillance system for Bluetongue using scenario tree modelling and (iii) a framework for risk-based residue monitoring. Surveys to substantiate freedom from infectious bovine rhinotracheitis and enzootic bovine leucosis between 2002 and 2009 saved over 6 million € by applying a risk-based sample size calculation approach, and by taking into account prior information from repeated surveys. An open, progressive policy making process stimulates research and science to develop risk-based and cost-efficient survey methodologies. Early involvement of policy makers in scientific developments facilitates implementation of new findings and full exploitation of benefits for producers and consumers.     

Parrot psychology and behavior problems.

Behavior modification training, like veterinary medicine, is an exacting science, requiring a knowledge of not only wild avian behavior, but of child and adult human behavior as well. It is important to note that absolutely any changes in a bird's or its owner's environment may trigger a vast assortment undesirable behaviors. Some behavior problems are simple, but most have multiple causes and each of those causes must be determined and corrected before a high rate of success is evident. As in veterinary medicine, some birds respond to general "shotgun" techniques; however, parrots are intelligent and complex creatures. They consider themselves an integral part of their human "flock" and respond as such. Most commonly seen negative behaviors can be altered, at least to some extent, and, in most cases, they can be alleviated completely. Yelling at the bird, striking it, or any other type of confrontational behavior modification technique is virtually useless and can actually worsen most situations. A high percentage of success involves extensive history taking, an understanding of human and wild animal flock behavior, and the time to create a complete program for each individual and its owner.