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The national animal health monitoring system: Fulfilling a commitment
Preventive Veterinary Medicine, 8 (1990) 89-95
89
Elsevier Science Publishers B.V., Amsterdam - - Printed in The Netherlands
The N a t i o n a l A n i m a l Health M o n i t o r i n g System: Fulfilling a Commitment L.J. KING
U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services, 320-E Administration Building, P.O. Box 96464, Washington, DC 20090-6464
(U.S.A.) T HE NEED FOR MONITORING HAS LONG BEEN RECOGNIZED
The food-animal industries, those associated with them, and those attempting to serve their needs have long been aware of the need for valid information on the occurrences, distribution, trends, and economic losses of animal diseases. Although the literature is filled with examples of individual workers and groups who have extolled the virtues and benefits of such information, there has been general disagreement about the methodology and the appropriate roles of those generating data. This has led to inaction and has undermined the development of an activity acknowledged as essential by so many. A Historical Survey of Animal Disease Morbidity and Mortality Reporting was published by The National Academy of Sciences' National Research Council in 1966 (Poppensiek and Budd, 1966). This report reviewed previous activities relating to animal disease reporting in the U.S.A. The report recognized that "dependable statistics on morbidity and mortality of animals is a fundamental principle of successful disease prevention and control". Credit was given to past efforts (including experimental state programs and foreign programs), but the committee preparing the report recommended that a national system should be implemented to define animal disease problems accurately through effective morbidity and mortality reporting. In addition, the group recommended that a central agency should be established to coordinate and implement this effort. EARLY A T T E M P T S LACKED UTILITY
McCallon and Beal (1982) traced early efforts in disease reporting and the prevailing philosophy in support of these previous programs. They identified "traditional systems" that included the National Report of Animal Diseases (NRAD), which consisted of monthly reports generated through private veterinary practitioners (often augmented by records from veterinary school clinics and/or state diagnostic laboratories ). The National Animal Morbidity Re0167-5877/90/$03.50
© 1990 Elsevier Science Publishers B.V.
90
L.J. KING
port (NAMR) was developed to supplement the NRAD and, in general, covered disease control and eradication programs (such as the brucellosis program) and those diseases ancillary to eradication programs (e.g. Johne's disease, scabies, rabies, and anthrax). After several critical reviews, the NRAD was discontinued. It was viewed as expensive, biased, often misleading, and of little practical utility. This traditional system is still commonly found world-wide; yet, disease prevalence, incidence, trends, or economic significance cannot be estimated from such a system. Even with this realization, "traditionalists" believed that the system should be continued; one merely needed to include more reporting veterinarians. There have also been those who thought that only diagnostic laboratory data should be collected, because the validity of these data would be much greater (McCallon and Beal, 1982). Others supported the concept of "lumping" all reports from the traditional systems, laboratories, meat inspection, and any other data source. However, these approaches often resulted in invalid conclusions and limited information with very little practical use. A second report was issued through the National Academy of Sciences in 1974 (Hutton and Halvorson, 1974). A special panel of the Committee on Animal Health acknowledged that scientifically reliable information on animal diseases was essential to the improvement of the health of animal populations across the U.S.A., yet a nationwide system focusing on morbidity and mortality reporting had still not been developed. The panel proposed that a nationwide system should be established together with a center "to serve as a national focal point for collecting, compiling, analyzing, and disseminating information on the incidence, prevalence, and costs of animal diseases". The center would be organized to include divisions of epidemiology, economics, and field services. The panel discussed the feasibility of such a system and its many benefits. An appreciation resurfaced for the need to identify the animals or populations at risk relative to disease or affected cases (denominator data). Data that merely sum up cases without knowledge of their population base (numerator data) have little usefulness. After the second Academy report, a group at the University of Minnesota began work on a reporting and surveillance system for Minnesota (Diesch et al., 1974 ). A statistically determined number of herds from various parts of the state were selected randomly and surveyed by private practitioners and, for the first time, inferences could be drawn on disease prevalences and trends. The Minnesota study was a significant step, and was a progenitor of the National Animal Health Monitoring System (NAHMS). A validation study of the Minnesota system suggested that veterinary practitioners' data was inherently biased and that information on the costs of disease would be beneficial (Diesch et al., 1979). In 1981, the Committee on Morbidity and Mortality Reporting of the United States Animal Health Association (USAHA) unanimously endorsed an initi-
NAHMS: FULFILLING A COMMITMENT
91
ative by the Animal and Plant Health Inspection Service (APHIS) of the U.S. Department of Agriculture to develop a National Animal Disease Surveillance system (NADS) (Poppensiek et al., 1981 ). The system emphasized valid data collection and its unbiased interpretation. Statistically sound requirements and the random selection of herds would eventually allow for estimates and inferences for entire populations at risk. This pilot project, which started in Ohio and Tennessee, involved the development of methods, and was the precursor of the NAHMS. This USAHA Committee also recognized that a central focus was necessary, and sanctioned the leadership role of APHIS, Veterinary Services. D E T E C T I O N vs. S U R V E I L L A N C E ( M O N I T O R I N G )
The use of the term NADS that initially described the USDA project met with opposition from some representatives of the food-animal industry. To them, the term "surveillance" connoted a covert activity and governmental intrusion. In deference to the industry, the activity changed names and was referred to as the National Animal Disease Detection System (NADDS). However, those working in this field and on the project understood that the term "detection" was not an accurate description of the system. The term "detection" implies the ascertainment of a single case (diseased animal), yet the project was designed to estimate the level of disease and health in populations. It was obvious that the epidemiological definition of surveillance was quite different from the common usage of the term. Thus, a final name change was introduced - the National Animal Health Monitoring System. Not only does the name more accurately describe the system, but it also emphasizes that - in our food-animal populations - the state of health is generally the norm. It is as important to define and assess the measurements and parameters of healthy herds and populations and the managerial and economic factors associated with these findings as it is to identify the disease state of individual animals. The terms surveillance and monitoring are synonymous in an epidemiological sense. P I L O T S T U D I E S LEAD T O R E F I N E M E N T AND E V A L U A T I O N OF M E T H O D O L O G Y
Pilot projects were used to test implementational strategies and methodological development (King, 1986). This phase of the NAHMS development used the support and expertise of state Departments of Agriculture and colleges of veterinary medicine. A great deal of enthusiasm and knowledge was generated through the pilot efforts. All segments of the livestock and poultry industries were included. Practical data-collection forms and techniques were derived from these experiences as was data analysis and presentation formats. A database management system with an analytical component was eventually
92
L.J. KING
adopted that emphasized the use of microcomputers rather than the more expensive minicomputers or mainframes. The NAHMS uses a stratified, random sampling technique with regard to probability in proportion to size (King, 1985). Randomly selected herds/flocks are also stratified according to relative herd/flock size (small, medium, large) and according to their respective species and production type, e.g. cattle: dairy cattle, feedlot cattle, cow-calf operations. When inferences are derived from the findings, comparisons can be made only within these defined population subsets. The NAHMS continues to work towards establishing national summaries for the various population subsets. As we progress towards a national system, we realize the importance of local, state and regional results. To accommodate these needs and to encourage the continuous support and contributions of the states and university systems, statewide sampling can be increased in interested states (to levels where it is appropriate to make inferences on animal populations within the state concerned). Cooperative ventures and sharing resources have proved to be attractive mechanisms. Although the additional sampling is not needed for a national summary, unique problems and special interests in certain states or regions can be more closely studied and better defined as the sample size increases and appropriate diagnostic support is incorporated in the sampling strategy. The established goal for the NAHMS is to develop national summaries for all food-animal species (King, 1986). The program will produce the first national disease summary next year, using the hog industry as a model, and focusing on a few specific outcomes. Although veterinarians visit participating farmsteads on a monthly basis, most health-related events and their estimated economic effects are monitored and tracked daily by the producer or owner. These data reflect the continuous monitoring of disease and production events for an entire year. Only through such a longitudinal study approach can we provide measurements of health as well as of disease, and establish accurate standards for production efficiencies to serve as reference points and targets for food-animal producers. After these years of pilot projects, there is confidence that producers can do a sufficient job of monitoring health-related events, tracking costs, and categorizing their findings in generic categories (e.g. reproductive, respiratory, gastrointestinal, injury). Such generic information and the estimated costs of these problems have never been acquired on a national basis, and, by themselves, are most worthwhile. The producer-generated data represent the "core" database of NAHMS. However, validation and further delineation of these disease problems is needed. Through the pilot projects, diagnostic "subsampling" routines were initiated toward this goal. Concurrent collections and analyses of diagnostic samples in support of the core NAHMS database is deemed essential to the improvement of the specificity and integrity of the information. Besides the diagnostic subsampling, the NAHMS data also include some
NAHMS: FULFILLING A COMMITMENT
93
detail on the costs of disease problems. The estimation of the economic burden of diseases helps clarify and define the food-animal disease issues. This economic information has proved to be the most desired and useful data for participating producers. It has often become the standard of comparison between producers and has greatly increased producers' awareness of animal health problems. In many instances, converting traditional biological and production measurements into economic parameters has been the justification and impetus for producers to adjust management decisions and to improve their efficiency of production. Such objective measurements can and will be used as a basis for planned improvement, production projections, and performance optimization. The NAHMS links the disciplines of epidemiology and economics in evaluating causal relationships, predicting and measuring losses, and prescribing effective prevention or control strategies. The future strategy of NAHMS is to phase out pilot projects, build the national database with a narrow focus, and incrementally implement studies that include other species and have a broader focus. Concurrently, scientific credibility will continue to be built, as will an emphasis on quality and service. The NAHMS is now a descriptive epidemiologic database; yet the prospect of advancing towards the analysis of interventional strategies and risk factors and eventually the modeling and prediction of events is extremely compelling, and may have an extraordinary payoff. PROPITIOUS TIMES FOR THE NAHMS CONCEPT Unlike the past, when surveillance systems were first being discussed, information technology is now available to support such an effort. Great advances in computer systems now enable us to explore, manipulate, and analyze huge data sets, which have opened up a new vista in population medicine, disease management, and the definition of health parameters both economically and biologically. The past focus of veterinary medicine was to reduce the occurrence of diseases causing mortality. Now producers, who are becoming more sophisticated and competitive, and who have new needs, are increasingly concerned with improved production efficiency and the attainment of target performances. Monitoring systems and record-keeping at the farm level have taken on a new significance. The early push for a surveillance system only to monitor mortality and morbidity events is too restrictive in terms of producers' needs today. Multidisciplinary teams are needed to work collectively on the complexities of food-animal health problems. The NAHMS is a strategic effort by public veterinary medicine to build the capacity and foundation needed for improved decision-making, and provide a means to study interventional strategies. Future cooperative efforts between public and private sectors mutually concerned about animal health will often center on the NAHMS data. Competitive po-
94
L.J. KING
sitions in the market-place (both domestically and internationally) will depend on our ability to prove the health of our food-animal populations. Producers are reassessing the need for identification systems for individual animals and certification programs to acknowledge safe and wholesome products. Food safety is demanded by the public, with assurances that animal products are free of biological and chemical residues. It is only logical that the NAHMS and similar activities will be needed in this important endeavor to maintain the public's confidence and build market share. In addition, new technology is revolutionizing diagnostic capabilities. New diagnostic test kits for use at the farm level will aid in the diagnostic subsampling for the NAHMS. Certainly, animal health monitoring is an idea whose time has come. NAHMS REAFFIRMSTHE USDAMISSION Sharing information between the USDA and the state and industry groups is the very heart of agriculture. The legislative act that created the USDA in 1862 mandated its mission "to acquire and diffuse among the people of the U.S. useful information on subjects connected with agriculture in the most general and comprehensive sense of the word" ( Statutory Law 387, 1862 ). The NAHMS not only reaffirms this mission, but also is responsive to the recommendations that have been made so thoughtfully and diligently over the last few decades. This past wisdom suggests that NAHMS must be implemented for the continuous redefinition of animal health priorities as past problems are resolved and new needs arise. The perfection of a comprehensive animal health monitoring system may prove to be one of the most important contributions of public veterinary medicine. Through the NAHMS program, food-animal disease rates, trends, and economic burdens can be estimated accurately with a local, state, or national focus. Ultimately, this methodology will be an essential tool to prevent, eliminate, or control health hazards in food-animal production. This should reduce economic losses and wasted energy resources which result from existing and emerging diseases. The NAHMS represents an important effort of public veterinary medicine to adapt to and meet new needs of the rapidly changing food-animal industries and demands of the public. The availability of scientifically and statistically reliable information is essential to the improvement of the health and productivity of animal populations. Although not a traditional USDA program, the NAHMS places a premium on a traditional USDA objective - the exchange of information - which is very much the business of animal health and a fulfillment of the commitment that the USDA made over a century ago.
NAHMS: FULFILLING A COMMITMENT
95
REFERENCES Diesch, S.L., Johnson, D.W., Martin, F.B., Christensen, L.T. and Revsbech, R., 1979. Validation of the Minnesota food animal disease reporting system. Report of Cooperative Agreement, USDA, APHIS, VS, Hyattsville, MD. Diesch, S.L, Martin, F.B., Johnson, D.W. and Christensen, L.T., 1974. The Minnesota animal disease reporting system for food producing animals. Proc. U.S. Anim. Health Assoc., pp. 327. Hutton, N.E. and Halvorson, L.C., 1974. A Nationwide System for Animal Health Surveillance. National Academy of Sciences, Washington, DC, 56 pp. King, L.J., 1985. Unique characteristics of the National Animal Disease Surveillance System. J. Am. Vet. Med. Assoc., 186: 35-39. King, L.J., 1986. The National Animal Health Monitoring System: an early assessment. Proc. U.S. Anim. Health Assoc., pp. 86-91. McCallon, W.R. and Beal, V.C., 1982. Historical aspects of animal disease reporting and the development of a national animal disease surveillance system. Proc. U.S. Anim. Health Assoc., pp. 341-349. Poppensiek, G.C. and Budd, D.E., 1966. In: C.R. Schroeder and M.R. Clarkson {Editors), A Historical Survey of Animal Disease Morbidity and Mortality Reporting. National Academy of Sciences, National Research Council, Washington, DC, Publ. 1346, pp. 1-24. Poppensiek, G.C. and Combs, G.C., 1981. Report of the Committee of Morbidity and Mortality. Proc. U.S. Anita. Health Assoc., pp. 1-6. Statutory Law 387, 15 May 1862.
89
Elsevier Science Publishers B.V., Amsterdam - - Printed in The Netherlands
The N a t i o n a l A n i m a l Health M o n i t o r i n g System: Fulfilling a Commitment L.J. KING
U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services, 320-E Administration Building, P.O. Box 96464, Washington, DC 20090-6464
(U.S.A.) T HE NEED FOR MONITORING HAS LONG BEEN RECOGNIZED
The food-animal industries, those associated with them, and those attempting to serve their needs have long been aware of the need for valid information on the occurrences, distribution, trends, and economic losses of animal diseases. Although the literature is filled with examples of individual workers and groups who have extolled the virtues and benefits of such information, there has been general disagreement about the methodology and the appropriate roles of those generating data. This has led to inaction and has undermined the development of an activity acknowledged as essential by so many. A Historical Survey of Animal Disease Morbidity and Mortality Reporting was published by The National Academy of Sciences' National Research Council in 1966 (Poppensiek and Budd, 1966). This report reviewed previous activities relating to animal disease reporting in the U.S.A. The report recognized that "dependable statistics on morbidity and mortality of animals is a fundamental principle of successful disease prevention and control". Credit was given to past efforts (including experimental state programs and foreign programs), but the committee preparing the report recommended that a national system should be implemented to define animal disease problems accurately through effective morbidity and mortality reporting. In addition, the group recommended that a central agency should be established to coordinate and implement this effort. EARLY A T T E M P T S LACKED UTILITY
McCallon and Beal (1982) traced early efforts in disease reporting and the prevailing philosophy in support of these previous programs. They identified "traditional systems" that included the National Report of Animal Diseases (NRAD), which consisted of monthly reports generated through private veterinary practitioners (often augmented by records from veterinary school clinics and/or state diagnostic laboratories ). The National Animal Morbidity Re0167-5877/90/$03.50
© 1990 Elsevier Science Publishers B.V.
90
L.J. KING
port (NAMR) was developed to supplement the NRAD and, in general, covered disease control and eradication programs (such as the brucellosis program) and those diseases ancillary to eradication programs (e.g. Johne's disease, scabies, rabies, and anthrax). After several critical reviews, the NRAD was discontinued. It was viewed as expensive, biased, often misleading, and of little practical utility. This traditional system is still commonly found world-wide; yet, disease prevalence, incidence, trends, or economic significance cannot be estimated from such a system. Even with this realization, "traditionalists" believed that the system should be continued; one merely needed to include more reporting veterinarians. There have also been those who thought that only diagnostic laboratory data should be collected, because the validity of these data would be much greater (McCallon and Beal, 1982). Others supported the concept of "lumping" all reports from the traditional systems, laboratories, meat inspection, and any other data source. However, these approaches often resulted in invalid conclusions and limited information with very little practical use. A second report was issued through the National Academy of Sciences in 1974 (Hutton and Halvorson, 1974). A special panel of the Committee on Animal Health acknowledged that scientifically reliable information on animal diseases was essential to the improvement of the health of animal populations across the U.S.A., yet a nationwide system focusing on morbidity and mortality reporting had still not been developed. The panel proposed that a nationwide system should be established together with a center "to serve as a national focal point for collecting, compiling, analyzing, and disseminating information on the incidence, prevalence, and costs of animal diseases". The center would be organized to include divisions of epidemiology, economics, and field services. The panel discussed the feasibility of such a system and its many benefits. An appreciation resurfaced for the need to identify the animals or populations at risk relative to disease or affected cases (denominator data). Data that merely sum up cases without knowledge of their population base (numerator data) have little usefulness. After the second Academy report, a group at the University of Minnesota began work on a reporting and surveillance system for Minnesota (Diesch et al., 1974 ). A statistically determined number of herds from various parts of the state were selected randomly and surveyed by private practitioners and, for the first time, inferences could be drawn on disease prevalences and trends. The Minnesota study was a significant step, and was a progenitor of the National Animal Health Monitoring System (NAHMS). A validation study of the Minnesota system suggested that veterinary practitioners' data was inherently biased and that information on the costs of disease would be beneficial (Diesch et al., 1979). In 1981, the Committee on Morbidity and Mortality Reporting of the United States Animal Health Association (USAHA) unanimously endorsed an initi-
NAHMS: FULFILLING A COMMITMENT
91
ative by the Animal and Plant Health Inspection Service (APHIS) of the U.S. Department of Agriculture to develop a National Animal Disease Surveillance system (NADS) (Poppensiek et al., 1981 ). The system emphasized valid data collection and its unbiased interpretation. Statistically sound requirements and the random selection of herds would eventually allow for estimates and inferences for entire populations at risk. This pilot project, which started in Ohio and Tennessee, involved the development of methods, and was the precursor of the NAHMS. This USAHA Committee also recognized that a central focus was necessary, and sanctioned the leadership role of APHIS, Veterinary Services. D E T E C T I O N vs. S U R V E I L L A N C E ( M O N I T O R I N G )
The use of the term NADS that initially described the USDA project met with opposition from some representatives of the food-animal industry. To them, the term "surveillance" connoted a covert activity and governmental intrusion. In deference to the industry, the activity changed names and was referred to as the National Animal Disease Detection System (NADDS). However, those working in this field and on the project understood that the term "detection" was not an accurate description of the system. The term "detection" implies the ascertainment of a single case (diseased animal), yet the project was designed to estimate the level of disease and health in populations. It was obvious that the epidemiological definition of surveillance was quite different from the common usage of the term. Thus, a final name change was introduced - the National Animal Health Monitoring System. Not only does the name more accurately describe the system, but it also emphasizes that - in our food-animal populations - the state of health is generally the norm. It is as important to define and assess the measurements and parameters of healthy herds and populations and the managerial and economic factors associated with these findings as it is to identify the disease state of individual animals. The terms surveillance and monitoring are synonymous in an epidemiological sense. P I L O T S T U D I E S LEAD T O R E F I N E M E N T AND E V A L U A T I O N OF M E T H O D O L O G Y
Pilot projects were used to test implementational strategies and methodological development (King, 1986). This phase of the NAHMS development used the support and expertise of state Departments of Agriculture and colleges of veterinary medicine. A great deal of enthusiasm and knowledge was generated through the pilot efforts. All segments of the livestock and poultry industries were included. Practical data-collection forms and techniques were derived from these experiences as was data analysis and presentation formats. A database management system with an analytical component was eventually
92
L.J. KING
adopted that emphasized the use of microcomputers rather than the more expensive minicomputers or mainframes. The NAHMS uses a stratified, random sampling technique with regard to probability in proportion to size (King, 1985). Randomly selected herds/flocks are also stratified according to relative herd/flock size (small, medium, large) and according to their respective species and production type, e.g. cattle: dairy cattle, feedlot cattle, cow-calf operations. When inferences are derived from the findings, comparisons can be made only within these defined population subsets. The NAHMS continues to work towards establishing national summaries for the various population subsets. As we progress towards a national system, we realize the importance of local, state and regional results. To accommodate these needs and to encourage the continuous support and contributions of the states and university systems, statewide sampling can be increased in interested states (to levels where it is appropriate to make inferences on animal populations within the state concerned). Cooperative ventures and sharing resources have proved to be attractive mechanisms. Although the additional sampling is not needed for a national summary, unique problems and special interests in certain states or regions can be more closely studied and better defined as the sample size increases and appropriate diagnostic support is incorporated in the sampling strategy. The established goal for the NAHMS is to develop national summaries for all food-animal species (King, 1986). The program will produce the first national disease summary next year, using the hog industry as a model, and focusing on a few specific outcomes. Although veterinarians visit participating farmsteads on a monthly basis, most health-related events and their estimated economic effects are monitored and tracked daily by the producer or owner. These data reflect the continuous monitoring of disease and production events for an entire year. Only through such a longitudinal study approach can we provide measurements of health as well as of disease, and establish accurate standards for production efficiencies to serve as reference points and targets for food-animal producers. After these years of pilot projects, there is confidence that producers can do a sufficient job of monitoring health-related events, tracking costs, and categorizing their findings in generic categories (e.g. reproductive, respiratory, gastrointestinal, injury). Such generic information and the estimated costs of these problems have never been acquired on a national basis, and, by themselves, are most worthwhile. The producer-generated data represent the "core" database of NAHMS. However, validation and further delineation of these disease problems is needed. Through the pilot projects, diagnostic "subsampling" routines were initiated toward this goal. Concurrent collections and analyses of diagnostic samples in support of the core NAHMS database is deemed essential to the improvement of the specificity and integrity of the information. Besides the diagnostic subsampling, the NAHMS data also include some
NAHMS: FULFILLING A COMMITMENT
93
detail on the costs of disease problems. The estimation of the economic burden of diseases helps clarify and define the food-animal disease issues. This economic information has proved to be the most desired and useful data for participating producers. It has often become the standard of comparison between producers and has greatly increased producers' awareness of animal health problems. In many instances, converting traditional biological and production measurements into economic parameters has been the justification and impetus for producers to adjust management decisions and to improve their efficiency of production. Such objective measurements can and will be used as a basis for planned improvement, production projections, and performance optimization. The NAHMS links the disciplines of epidemiology and economics in evaluating causal relationships, predicting and measuring losses, and prescribing effective prevention or control strategies. The future strategy of NAHMS is to phase out pilot projects, build the national database with a narrow focus, and incrementally implement studies that include other species and have a broader focus. Concurrently, scientific credibility will continue to be built, as will an emphasis on quality and service. The NAHMS is now a descriptive epidemiologic database; yet the prospect of advancing towards the analysis of interventional strategies and risk factors and eventually the modeling and prediction of events is extremely compelling, and may have an extraordinary payoff. PROPITIOUS TIMES FOR THE NAHMS CONCEPT Unlike the past, when surveillance systems were first being discussed, information technology is now available to support such an effort. Great advances in computer systems now enable us to explore, manipulate, and analyze huge data sets, which have opened up a new vista in population medicine, disease management, and the definition of health parameters both economically and biologically. The past focus of veterinary medicine was to reduce the occurrence of diseases causing mortality. Now producers, who are becoming more sophisticated and competitive, and who have new needs, are increasingly concerned with improved production efficiency and the attainment of target performances. Monitoring systems and record-keeping at the farm level have taken on a new significance. The early push for a surveillance system only to monitor mortality and morbidity events is too restrictive in terms of producers' needs today. Multidisciplinary teams are needed to work collectively on the complexities of food-animal health problems. The NAHMS is a strategic effort by public veterinary medicine to build the capacity and foundation needed for improved decision-making, and provide a means to study interventional strategies. Future cooperative efforts between public and private sectors mutually concerned about animal health will often center on the NAHMS data. Competitive po-
94
L.J. KING
sitions in the market-place (both domestically and internationally) will depend on our ability to prove the health of our food-animal populations. Producers are reassessing the need for identification systems for individual animals and certification programs to acknowledge safe and wholesome products. Food safety is demanded by the public, with assurances that animal products are free of biological and chemical residues. It is only logical that the NAHMS and similar activities will be needed in this important endeavor to maintain the public's confidence and build market share. In addition, new technology is revolutionizing diagnostic capabilities. New diagnostic test kits for use at the farm level will aid in the diagnostic subsampling for the NAHMS. Certainly, animal health monitoring is an idea whose time has come. NAHMS REAFFIRMSTHE USDAMISSION Sharing information between the USDA and the state and industry groups is the very heart of agriculture. The legislative act that created the USDA in 1862 mandated its mission "to acquire and diffuse among the people of the U.S. useful information on subjects connected with agriculture in the most general and comprehensive sense of the word" ( Statutory Law 387, 1862 ). The NAHMS not only reaffirms this mission, but also is responsive to the recommendations that have been made so thoughtfully and diligently over the last few decades. This past wisdom suggests that NAHMS must be implemented for the continuous redefinition of animal health priorities as past problems are resolved and new needs arise. The perfection of a comprehensive animal health monitoring system may prove to be one of the most important contributions of public veterinary medicine. Through the NAHMS program, food-animal disease rates, trends, and economic burdens can be estimated accurately with a local, state, or national focus. Ultimately, this methodology will be an essential tool to prevent, eliminate, or control health hazards in food-animal production. This should reduce economic losses and wasted energy resources which result from existing and emerging diseases. The NAHMS represents an important effort of public veterinary medicine to adapt to and meet new needs of the rapidly changing food-animal industries and demands of the public. The availability of scientifically and statistically reliable information is essential to the improvement of the health and productivity of animal populations. Although not a traditional USDA program, the NAHMS places a premium on a traditional USDA objective - the exchange of information - which is very much the business of animal health and a fulfillment of the commitment that the USDA made over a century ago.
NAHMS: FULFILLING A COMMITMENT
95
REFERENCES Diesch, S.L., Johnson, D.W., Martin, F.B., Christensen, L.T. and Revsbech, R., 1979. Validation of the Minnesota food animal disease reporting system. Report of Cooperative Agreement, USDA, APHIS, VS, Hyattsville, MD. Diesch, S.L, Martin, F.B., Johnson, D.W. and Christensen, L.T., 1974. The Minnesota animal disease reporting system for food producing animals. Proc. U.S. Anim. Health Assoc., pp. 327. Hutton, N.E. and Halvorson, L.C., 1974. A Nationwide System for Animal Health Surveillance. National Academy of Sciences, Washington, DC, 56 pp. King, L.J., 1985. Unique characteristics of the National Animal Disease Surveillance System. J. Am. Vet. Med. Assoc., 186: 35-39. King, L.J., 1986. The National Animal Health Monitoring System: an early assessment. Proc. U.S. Anim. Health Assoc., pp. 86-91. McCallon, W.R. and Beal, V.C., 1982. Historical aspects of animal disease reporting and the development of a national animal disease surveillance system. Proc. U.S. Anim. Health Assoc., pp. 341-349. Poppensiek, G.C. and Budd, D.E., 1966. In: C.R. Schroeder and M.R. Clarkson {Editors), A Historical Survey of Animal Disease Morbidity and Mortality Reporting. National Academy of Sciences, National Research Council, Washington, DC, Publ. 1346, pp. 1-24. Poppensiek, G.C. and Combs, G.C., 1981. Report of the Committee of Morbidity and Mortality. Proc. U.S. Anita. Health Assoc., pp. 1-6. Statutory Law 387, 15 May 1862.