The transmissible spongiform encephalopathies: disease risks for North America.

Transmissible spongiform encephalopathies exotic to North America (BSE and associated diseases) are unlikely to be introduced or to persist should they be introduced into the United States [2]. Domestic TSEs (scrapie, CWD, and TME) seem to be relatively restricted in their host range, and none of these diseases is known to naturally cause disease in cattle. It is important that surveillance for TSEs continues, however, particularly in cattle because of the extreme consequences to the livestock industries, and potentially, public health, if BSE becomes established. Because the TSEs have implications beyond effects on their natural host species, adequate surveillance, control, and even eradication of these diseases should be goals for the livestock industries, wildlife managers, and animal health agencies in the United States.     

Abattoir surveillance: the U.S. experience

Abattoir, or slaughter, surveillance has been an important component of bovine tuberculosis control and eradication programs in the U.S., and has adapted to changes in the livestock market from farm to table, and the threat of bovine tuberculosis from a wildlife reservoir. The purpose of this overview was to describe the current goals of U.S. bovine tuberculosis slaughter surveillance, describe the elements of slaughter surveillance in the U.S., describe enhancements to the slaughter surveillance system, and discuss future challenges for the U.S. bovine tuberculosis surveillance program. Government regulations and the scientific literature were examined to provide information for this paper. The control and eradication of bovine tuberculosis in livestock falls to the United States Department of Agriculture and two agencies within the Department: the Food Safety and Inspection Service (FSIS) and the Animal and Plant Health Inspection Service (APHIS). FSIS conducts routine slaughter surveillance for disease or conditions that render carcasses unsuitable for human consumption, while APHIS is involved in antemortem bovine tuberculosis testing, and necropsy and investigation of bovine tuberculosis cases identified through slaughter surveillance or antemortem testing. Results from the previous 5 years of surveillance are presented. Enhancements have been added to the current surveillance system to improve its performance. An incentive program has been used to increase the numbers of tissues submitted for laboratory examination, the state of Michigan is implementing electronic animal identification under a pilot program, and expansions to the current system are being developed to accommodate new livestock industries. The success of these programs and challenges for the future are discussed.     

Ovine scrapie. New tools for control of an old disease.

Ovine scrapie was described nearly 300 years ago and is endemic in many parts of the world. The recent emergence of a related bovine disease in the United Kingdom and Europe, with probable transmission to humans, has lent urgency to scrapie surveillance and control programs. The biology, genetics, diagnosis, and proposed routes of transmission can be understood in the context of the presumed causative agent, the prion protein. An integrated program of management and husbandry to reduce introduction and spread of the disease within a flock, diagnosis of preclinically infected sheep in both live animal and postmortem settings, and identification of breeding stock of low risk of scrapie are reviewed as the basis for scrapie eradication 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.     

Overview of issues pertaining to the manufacture, distribution, and use of antimicrobials in animals and other information relevant to animal antimicrobial use data collection in the United States

This paper provides condensed literature review and contextual information concerning antimicrobial use in animals and antimicrobial use data collection techniques. Information is summarized into the following topics: (I) antimicrobial use for animal growth promotion; (II) regulatory framework for approval of veterinary antimicrobials and feed additives in the United States; (III) animal health product manufacturing and distribution networks; (IV) existing estimates of animal antimicrobial use in the United States; (V) additional sources for animal use data in the United States; (VI) recommendations from international expert groups; (VII) animal antimicrobial use surveillance systems in other nations and (VIII) human use data collection systems in the United States.     

Veterinary public health: past success, new opportunities

Animal diseases are known to be the origin of many human diseases, and there are many examples from ancient civilizations of plagues that arose from animals, domesticated and wild. Records of attempts to control zoonoses are almost as old. The early focus on food-borne illness evolved into veterinary medicine's support of public health efforts. Key historical events, disease outbreaks, and individuals responsible for their control are reviewed and serve as a foundation for understanding the current and future efforts in veterinary public health. Animal medicine and veterinary public health have been intertwined since humans first began ministrations to their families and animals. In the United States, the veterinary medical profession has effectively eliminated those major problems of animal health that had serious public health ramifications. These lessons and experiences can serve as a model for other countries. Our past must also be a reminder that the battle for human and animal health is ongoing. New agents emerge to threaten human and animal populations. With knowledge of the past, coupled with new technologies and techniques, we must be vigilant and carry on.     

动物健康体系建设与公共卫生一体化构建研究

动物健康体系最初在澳大利亚和加拿大等国建立,在动物疾病防控方面起到了十分重要的作用.本文对澳大利亚已建立的动物健康体系和我国兽医医疗体制进行对比,分析在我国建立更合理的官方兽医制度和动物健康体系以加快兽医与人医公共卫生一体化进程的对策.     

动物健康体系构建研究

动物健康体系最初在澳大利亚和加拿大等国建立,在动物疾病防控方面起到了十分重要的作用。本文对澳大利亚已建立的动物健康体系和我国兽医医疗体制进行对比,分析在我国建立更合理的官方兽医制度和动物健康体系以加快兽医与人医公共卫生一体化进程的对策。     

Successful and currently ongoing parasite eradication programs

The eradication of parasitic diseases is not a new concept. The most successful programs of parasite eradication have occurred with species of veterinary importance. The first such program, the eradication of Texas Cattle Fever from the United States, is one of the great success stories of disease eradication. The American screwworm eradication program is ongoing and is serving as a guiding impetus for many of the ongoing or proposed vector eradication schemes around the world. The success of these programs prompted similar successful operations in human health. Although they once led the way, veterinary parasitologists have taken second place in eradication planning. The only three parasitic diseases of veterinary importance that have been targets of recent eradication programs are Hypoderma species in Great Britain and Europe, Cochliomyia hominivorax after its introduction into Libya from the Americas, and Echinococcus granulosus in Tasmania, Australia. There is also work on the eradication of the tick, Amblyomma variegatum, from the Caribbean Islands. Some animal diseases are targeted under the auspices of the human eradication programs, most notably the eradication of the tsetse fly from parts or all of Africa. This paper reviews some of the past or ongoing successful eradication programs and presents a brief summary of the history of the programs, the methods used or planned, and potential controversies surrounding their success and implementation.     

International programs and veterinary public health in the Americas—Success, challenges, and possibilities

The veterinary public health (VPH) program at the Pan American Health Organization (PAHO) began in 1949 when an arrangement with the newly founded World Health Organization made PAHO its Regional Office for the Americas to serve as the specialized health agency both for the Organization of American States and the United Nations. It started as a Section of Veterinary Medicine to help eradicate rabies on both sides of the US-Mexico border, and PAHO grew to be the biggest VPH program in the world. By providing a political and technical base, PAHO assisted its member states to organize and develop their national VPH programs and activities, and it provides technical cooperation and works with their national counterparts to solve national and local problems.In the 1980s and 1990s, PAHO concentrated that cooperation on several, specific needs: the elimination of dog-transmitted human rabies, hemispheric eradication of foot-and-mouth disease (FMD), regional action planning for food safety, control/eradication of bovine tuberculosis and brucellosis, and surveillance and prevention of emerging zoonoses and food-borne diseases. The Pan American centers developed a number of diagnostic antigens and a continental system for the surveillance of FMD and vesicular diseases, using geographic quadrant technology to augment sensitivity, analyze data, and make decisions. Another visible accomplishment is the elimination of hydatidosis in the endemic countries and regions of the southern cone.In addition, the VPH program of PAHO pioneered the mobilization of the private sector to participate in official programs. Nevertheless, privatization of animal and human health services has had a negative effect on human resources and infrastructure by weakening essential epidemiological functions in some countries.Today, there is a need for closer coordination between veterinary medicine and medical services. Practically all potential bioterrorism agents are zoonoses, and it is cost-effective to control them at the veterinary level, providing the first line of defense. The opportunities for VPH are boundless, but the challenge is to be able to apply the plethora of available research results and knowledge. What we will need is a new breed of veterinarians who will lead and provide us with a vision, like those we honored in 2005 at the Schwabe Symposium Honoring the Lifetime Achievements of Dr. James H. Steele: veterinarians in public health who will be in the forefront of policy setting, decision-making, and allocation of resources, and veterinarians who will articulate and provide a strategic direction to our unique professional skills.     

International programs and veterinary public health in the Americas--success, challenges, and possibilities

The veterinary public health (VPH) program at the Pan American Health Organization (PAHO) began in 1949 when an arrangement with the newly founded World Health Organization made PAHO its Regional Office for the Americas to serve as the specialized health agency both for the Organization of American States and the United Nations. It started as a Section of Veterinary Medicine to help eradicate rabies on both sides of the US-Mexico border, and PAHO grew to be the biggest VPH program in the world. By providing a political and technical base, PAHO assisted its member states to organize and develop their national VPH programs and activities, and it provides technical cooperation and works with their national counterparts to solve national and local problems. In the 1980s and 1990s, PAHO concentrated that cooperation on several, specific needs: the elimination of dog-transmitted human rabies, hemispheric eradication of foot-and-mouth disease (FMD), regional action planning for food safety, control/eradication of bovine tuberculosis and brucellosis, and surveillance and prevention of emerging zoonoses and food-borne diseases. The Pan American centers developed a number of diagnostic antigens and a continental system for the surveillance of FMD and vesicular diseases, using geographic quadrant technology to augment sensitivity, analyze data, and make decisions. Another visible accomplishment is the elimination of hydatidosis in the endemic countries and regions of the southern cone. In addition, the VPH program of PAHO pioneered the mobilization of the private sector to participate in official programs. Nevertheless, privatization of animal and human health services has had a negative effect on human resources and infrastructure by weakening essential epidemiological functions in some countries. Today, there is a need for closer coordination between veterinary medicine and medical services. Practically all potential bioterrorism agents are zoonoses, and it is cost-effective to control them at the veterinary level, providing the first line of defense. The opportunities for VPH are boundless, but the challenge is to be able to apply the plethora of available research results and knowledge. What we will need is a new breed of veterinarians who will lead and provide us with a vision, like those we honored in 2005 at the Schwabe Symposium Honoring the Lifetime Achievements of Dr. James H. Steele: veterinarians in public health who will be in the forefront of policy setting, decision-making, and allocation of resources, and veterinarians who will articulate and provide a strategic direction to our unique professional skills.     

Rabies postexposure prophylaxis. Human and domestic animal considerations.

The emphasis on rabies control and prevention in the United States seems to be a function of our perception of proximity of the threat. Wildlife rabies epizootics within a state may be of little concern to the uninformed urban dweller. Additionally, many parts of the western United States are free of terrestrial rabies; were it not for the presence of bat rabies, people in those areas would likely interpret rabies control as a minor public health concern. It is essential that federal, state, and local public health programs emphasize the importance of rabies control through activities that include rabies education, sponsorship of legislated requirements for domestic animal vaccination, support for local animal control programs, and the promotion of recommendations that encourage the appropriate use of PEP. We are almost guaranteed that rabies is going to remain a major public health issue well into the next century because of expanding wildlife rabies epizootics, identification of new rabies viral variants with increased public health concern, emotional and legal concerns associated with rabies exposure, and increasing national cost associated with rabies control and prevention. Nevertheless, the development of new laboratory technology that allows an understanding of the epidemiologic nature of the rabies virus based on an evolving genetic history and the interrelationship with wildlife reservoirs should allow access to valuable tools for rabies control. When combined with programs using new developments in oral rabies vaccine that can immunize whole populations of wildlife reservoirs, that technology offers encouragement in our effort to control one of the diseases of antiquity.     

International trade in livestock and livestock products: the need for a commodity-based approach

International animal health standards designed to facilitate safe trade in livestock and livestock products are set by the Office International des Epizooties (OIE) under the Sanitary and Phytosanitary Agreement of the World Trade Organization (WTO) and documented in the OIE's Terrestrial Animal Health Code. A core principle of the Code is the need for countries to eradicate important transboundary animal diseases (TADs) to reduce the risk of exporting disease to trading partners. International food safety standards are set by the Codex Alimentarius Commission, administered jointly by the World Health Organization and the Food and Agriculture Organization of the United Nations. The goal of global eradication of most TADs is unachievable for the foreseeable future, other than in the case of rinderpest, and this prevents many countries, especially developing nations, from engaging in international trade under WTO rules. This paper proposes an alternative, commodity-based approach to the formulation of international animal health and food safety standards, based on the fact that different commodities pose very different risks when it comes to the spread of human and animal pathogens. Therefore, the risk mitigation strategies required are equally commodity-dependent. The authors conclude that more focused commodity standards would improve access to international markets for all countries, especially those in the developing world. For this objective to be realised, credible and independent certification is required.     

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.     

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.     

Introduced ticks and tick-borne diseases: the threat and approaches to eradication.

Exotic tick species and tick-borne diseases are serious threats to live-stock, companion animals, and wildlife in the United States. Recurring introductions of exotic tick species into the United States are a significant indicator of the degree of risk. Successful tick-eradication campaigns, such as the national program that eradicated Boophilus annulatus and B. microplus from the United States, the Cattle Fever Tick Eradication Program of the US Department of Agriculture's Veterinary Services that protects against the re-entry and dissemination of Boophilus ticks from Mexico back into their former haunts in the southern states, and the eradication action that eliminated Rhipicephalus evertsi from a game park in Florida, are sources of useful information that aid in elucidating essential elements of successful eradication programs. Examples of failed eradication programs in places such as Puerto Rico and St. Croix also have heuristic value. Among the varieties of tick species and related infectious agents that threaten the United States, Boophilus ticks and bovine babesiosis, Amblyomma species (especially the tropical bont tick) and heartwater, and equine babesiosis, for which endemic vectors exist, are of special concern. Risk assessments to accumulate, evaluate, and synthesize information needed to appraise risks, consequences, and preparedness are necessary not just to inform federal, state, and local officials, as well as producers and stakeholders, but also to facilitate the creation of emergency response plans.     

Epidemiology and quality assurance: applications at farm level

Animal production is relevant with respect to farm income and the position of the sector in the market, but also with respect to the quality and safety of products of animal origin, related to public health. Animal production is part of a chain of food production. Therefore, producers have to take consumer expectations and demands in the domains of animal health, welfare and environment into account. A different attitude for production has to be adopted; this attitude can be visualized in good farming practice, GFP, codes. Farmers who focused on quality in its broadest sense need a system supporting them in their management and control of quality risks. Generally speaking, there are three systems for that purpose: GFP, ISO and HACCP. When the hypothesis followed relates to animal health being a feature of quality, or else welfare and environmental issues, then animal health care can be executed following quality control principles. The HACCP concept is well suited for quality control at farm level, involving risk identification and risk management. The on-farm monitoring and surveillance system of critical control points in the animal production process is the most important tool in this procedure. Principles for HACCP application as well as certification fitness of HACCP are elaborated upon. They are illustrated by using salmonellosis in meat-pig farms as objective for an HACCP approach. It is further discussed that, in addition to animal health and quality, animal welfare and environmental issues could also be covered by an HACCP-like system in an integrated manner. Ultimately, the HACCP modules could end up in an overall ISO certification.     

CRITTER: A database for managing research animals

We describe CRITTER, a computer database program for managing research animals. We designed it especially for institutions which operate health surveillance plans, such as specific pathogen-free schemes. Because CRITTER can be used to record any type of test result in any species of animal, it can be customized to suit each institution and its management protocol. In addition to maintaining a current inventory of each individual animal and its location, the program retains historical information on those that have been removed from the colony. Output summaries are generated by selecting from a menu of standard reports or by designing a custom query. Although CRITTER has been designed for individual research establishments, it could be modified for use in area health surveillance programs. CRITTER operates on IBM compatible computers using a menu-driven, runtime version of Paradox.     

What veterinary practitioners should know about scrapie

Scrapie is the longest known and most widely spread of the transmissible spongiform encephalopathies and remains the model for much of the research regarding these diseases. Because scrapie is a reportable disease and the subject of an active eradication program in the United States, veterinary practitioners should have a basic understanding of the disease.     

Training the veterinary public health workforce: a review of educational opportunities in US veterinary schools

This article presents the results of an Internet-based review conducted in January and February 2003 to assess the educational opportunities available in veterinary public health, epidemiology, and preventive medicine at the 27 veterinary schools in the United States. Most professional veterinary curricula are designed to train students for careers as highly qualified private practitioners, although there is an increased need for veterinary perspectives and contributions in the public health sector. The future of veterinary public health relies on the opportunities available in education to teach and encourage students to pursue a career of public service. The results of this review indicate the availability of a wide variety of required courses, electives, and post-graduate training programs to veterinary students in the United States. Veterinary students are exposed to a median of 60 hours of public health, epidemiology, and preventive medicine in required stand-alone courses in these areas. Four veterinary schools also have required rotations for senior students in public health, preventive medicine, or population medicine. Contact time for required public health, epidemiology, and preventive medicine courses ranges from 30 to 150 contact hours. Advanced training was available in these subjects at 79% of the 27 schools. Greater collaboration between veterinary schools, schools of public health, and the professional public health community will increase exposure to and opportunities in public health to all future veterinarians.