National Animal Health Monitoring System: Data-Driven Insights for a One Health Mission
One Health Newsletter: Volume 17, Issue 2
Introduction
ased out of Fort Collins, Colorado, is a small unit within the United States Department of Agriculture (USDA) called the National Animal Health Monitoring System (NAHMS). Perhaps because of this smaller size, many members of the public are not aware of the nature or importance of the work NAHMS produces. However, the studies conducted and the data amassed by this group have wide-ranging importance for our understanding of animal health, agricultural production, and human health in the United States (U.S.). Recent studies have focused on various aspects of the animal agriculture industry, including large and small swine enterprises, cattle feedlot management, and the sheep industry. While NAHMS exists outside of the traditional regulatory role of other programs that are also part of the USDA Animal and Plant Health Inspection Service (APHIS), the information provided is widely available in academic and industry publications, and can inform decisions made within different sectors of animal agriculture (Weigler et al., 1990). Through this, NAHMS findings address and impact the health of animals used in agriculture, the health of humans who depend on food and fiber products from those animals, and the health of the environment in which animals live, cementing it firmly within a One Health framework. Indeed, NAHMS offers a data-driven tool to support the mission of addressing human and veterinary public health threats.
A Strategic Data-Collection Approach
Today, NAHMS surveys follow a cyclical process of development, data collection, and analysis; they have historically also operated on a rotating, repeating schedule. In a strategic approach, NAHMS established calendars of future studies seven to ten years in advance, with the expectation of periodic repeats to allow for monitoring of trends. This life cycle is made of five primary phases, taking often three to four years for full survey cycle completion. Studies begin with a needs assessment phase that solicits input from stakeholders and other subject matter experts (Haley, 2009). Planning begins through a study design phase, and then a study implementation phase maps out study logistics and execution plans. The next step involves the preparation of various reports that summarize and contextualize findings; these are disseminated to stakeholders (e.g., the animal agriculture industry as well as public health scientists) and the public (Haley, 2009).
Over the past ten to 15 years, scheduled surveys have been shortened, with plans extending only about three years into the future; this change was in response to criticism that a lack of flexibility was hampering the ability to respond to evolving information needs (N. Marshall, personal communication, 6 December 2024). Study timelines remain flexible to accommodate challenges and changes over time, but with only anticipated end dates for data collection (and no set timeline for data reporting and analysis), data is increasingly collected but not analyzed and published by USDA scientists; to fill this gap, universities and other agencies now participate in analysis and publication (N. Marshall, personal communication, 6 December 2024). Budgetary considerations factor into planning and decisions, with cooperative agreements necessary throughout the entire study lifecycle; this includes contracts with private survey companies to administer phone and online questionnaires (N. Marshall, personal communication, 6 December 2024).
Each study operates on an independent "life cycle" beginning with a needs assessment that, if a similar study was previously performed, stems from those findings (Hueston, 1990). Data is collected and then analyzed, and data summaries and information sheets are prepared for stakeholders and policymakers. Studies operate simultaneously; when one study is underway, others have already begun in their initial stages, including a needs assessment and initial field tests of questionnaires and data collection procedures (Hueston, 1990). Both economic and epidemiologic trends influence the topics selected for a study; therefore, new studies sometimes join an already crowded field of competing priorities. For example, a 2019 goat study was initiated partially in response to an increasing number of agritourism businesses and the high profile of disease outbreaks, especially when illnesses in children were linked back to these operations (N. Marshall, personal communication, 6 December 2024).
The Value of NAHMS for Both Producers and Public Health Practitioners
Through data collected, NAHMS studies contribute to nationwide analyses and are the basis for further studies by government, academic, and industry groups. To incentivize survey and study participation by producers, biological sampling data (e.g., blood tests and fecal parasite analysis, with results) are provided back to those producers (Wineland & Dargatz, 1998). When study findings are released by NAHMS, a large number of industry publications share the information gathered, contextualizing it with recommendations (often from extension agents and veterinarians), helping producers benefit from the data. The reference points and targets provided by these repeated cross-sectional studies can aid in developing improved and more efficient, and cost-effective management techniques (Weigler et al., 1990; King, 1990). Information from studies, including quantitative data, provides reliable insights into the health and productivity of livestock and other food-producing animals; this is especially useful for policymakers and regulators (Bush et al., 1995).
Advancing the One Health Mission
Because of the emphasis on food animals, NAHMS studies impact human health issues related to food safety and zoonotic disease. The collected data can serve an essential role in supporting the development of programs and policies to prevent or mitigate human health hazards, such as pathogens that cause food-borne diseases (King, 1990). These can be public programs, such as through local departments of public health, or private endeavors, run by industry or producers themselves. Previous studies have focused on collecting farm-level data regarding antimicrobial resistance and pathogens that include Escherichia coli O157:H7, Salmonella spp., Campylobacter jejuni, Coxiella burnetii, and Listeria monocytogenes (Wineland & Dargatz, 1998). Significantly, NAHMS is the sole provider of national on-farm data on antimicrobial resistance, including information provided for a national action plan to combat antimicrobial resistance (N. Marshall, personal communication, 6 December 2024).
Studies initiated by NAHMS have not only described the prevalence and distribution of pathogens but also evaluated the factors for shedding that could increase the risk to the general public (Wineland & Dargatz, 1998). Furthermore, NAHMS-led studies guide the supply of high-quality food products essential to the U.S.'s food security (Hueston, 1990). There is also value in monitoring and describing the incidence of and risk factors for zoonotic disease independent of the food supply, such as the transmission of highly pathogenic avian influenza (HPAI) from backyard poultry and dairy cattle to owners and workers.
Conclusion
Through its data-driven approach, NAHMS focuses on animal health, agricultural practices, and potential public health impacts. These studies' goals and findings demonstrate clear principles of the concept of One Health. Human health is tied to animal health, through the role healthy and productive animals have in contributing to a safe and secure domestic food supply. Zoonotic diseases and rising antimicrobial resistance link the health of humans and animals. The data provided by NAHMS studies helps guide changes that can continue to improve the health of all species.
References
Weigler B. J, Hird, D. W., Sischo, W. M., Holmes, J. C., Danaye-Elmi, C., Palmer, C.W., and Utterback, W.W. (1990). Veterinary and nonveterinary costs of disease in 29 California dairies participating in the National Animal Health Monitoring System from 1988 to 1989. Journal of the American Veterinary Medical Association 196 (12):1945-1949. doi:10.2460/javma.1990.196.12.1945
King, L. J. (1990). The National Animal Health Monitoring System: Fulfilling a commitment. Prev Vet Med. 8, 89-95. doi:10.1016/0167-5877(90)90002-Y
Marshall, N. (2024). Personal communication to Victoria Neff. December 6, 2024.
Wineland, N. E., & Dargatz, D. A. (1998). The National Animal Health Monitoring System: A source of on-farm information. Vet Clin North Am Food Anim Pract. 1998;14(1):127-139. doi:10.1016/s0749-0720(15)30284-x
Farrar, J. (1988). The National Animal Health Monitoring System (NAHMS): progression from a pilot project to a national program. Acta Vet Scand. 1988;Supplementum 84:191-193.
Haley, C. (2009). The USDA’s National Animal Health Monitoring System. In: Proceedings of the 2009 London Swine Conference, 2009:83-94. Accessed April 14, 2025. https://cdn.prod.website-files.com/5d93b00ac916fc5ea0c1750d/5dcf0cbce9864c458ed9a754_2009.pdf
Hueston, W. D. (1990). The National Animal Health Monitoring System: Addressing animal health information needs in the U.S.A. Prev Vet Med. 8:97-102. doi:10.1016/0167-5877(90)90003-Z
Bush, E. J., Cowen P., Morgan Morrow, W. E., Dickey, D. A., & Zering, K.D. (1995). Evaluation of non-sampling errors in the US National Swine Survey. Prev Vet Med. 22:155-168. doi:10.1016/0167-5877(94)00415-F
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