Developing Methods to Evaluate and Mitigate Impacts Of Wildlife-Associated Pathogens Affecting Agricultural Health, Food Security and Food Safety
Objective 1: Identifying transmission risks and farm-side vectors from pathogenic viruses in wildlife.
Viruses associated with negative effects to agriculture and human health continue to persist as major pathogens in the U.S. and abroad. This area of research will lead to a better understanding of the potential roles of wildlife in human and animal health and safety, identify key control points for risk reduction, inform risk assessments, and contribute to best management practices.
Objective 2: Developing models for risk assessment and optimal control strategies for viral pathogen biosecurity from wildlife.
Avian influenza outbreaks, even low pathogenic outbreaks, result in significant economic losses to producers due to morbidity, mortality, and reduced output. Identifying and quantifying factors that have a significant impact on avian influenza dynamics allows for the development of quantitative models that can be used to assess risks and identify control points in order to optimize biosecurity, surveillance, and outbreak control. This area of research has important implications for agricultural health and food security in the U.S.
Objective 3: Assess impacts of wildlife in spread and transmission of pathogenic and anti-microbial resistant bacteria to and among agricultural systems.
Pathogenic and antimicrobial-resistant (AMR) bacteria have become an increasing problem over the last three decades in human health. For example, the CDC estimates that at least 2 million people in the U. S. acquire serious infections with AMR bacteria each year and at least 23,000 of these cases are fatal. Often, agricultural operations, such as concentrated livestock facilities, are implicated as the source of AMR and pathogenic bacteria infections. However, the contributions of AMR bacteria to the food chain and human health are poorly understood. Other sources, such as naturally occurring wildlife and urban areas, have not been adequately investigated. In addition, wildlife may serve as transmission mechanisms to and from agricultural facilities. These same mechanisms also apply to ultimate sources and transmission of pathogenic bacteria by wildlife.
Objective 4: Assess risks of pathogen introduction and spread in the U.S. by movement of wildlife and wildlife products.
There is a current lack of understanding on the potential role of wildlife in movement of pathogens that affect agricultural health and food safety. Although wildlife are surmised to play a role in movement of pathogens, there are few probabilistic statements that can be made concerning the likelihood of such introductions and spread of these pathogens. Recent development of unified databases, such as banding and recovery data from multiple continents, will allow for probabilistic inferences on waterfowl movement across continents. In addition, recent advances in statistical estimators, such as multi-state band recovery models and occupancy modeling, have direct applications to estimating transition probabilities that allow for imperfect detectability in both free-ranging wildlife and wildlife products smuggled into the U.S. A hotly debated topic associated with the ability of wildlife to introduce and spread pathogens is whether individuals are compromised by the pathogens they carry which would limit their ability as pathogen traffickers. For example, a sick bird is unlikely to transport a pathogen long distances, while a mildly-ill or bird with no signs of disease might transport a pathogen longer distances if it shed a requisite amount or had a viremia of sufficient magnitude. Studies examining this effect will thus complement those examining empirical estimates of wildlife movement.
Objective 5: Understanding the role of wildlife as reservoirs for novel pathogens that threaten food safety and security.
Understanding how wildlife contribute to pathogen persistence and transmission requires both baseline knowledge on what pathogens wildlife can reservoir and knowledge on the changing face of the conditions which impact disease dynamics. This area of research will increase our understanding on the pathogens wildlife carry, while also focusing on how species/disease introduction and climate change will affect disease dynamics. Findings will help elucidate control points and will inform on how to efficiently implement mitigation strategies.
Objective 6: Provide services and methods development to domestic and international entities on wildlife-associated pathogen issues relevant to One Health.
Project staff have expertise in ecology, sampling, statistical design and analysis, and laboratory analytical capabilities that can assist in the development of research, surveillance and monitoring strategies for pathogens of concern in wildlife at different scales. For example, there are a number of statistical estimators, based on mark-recapture theory, that have potential uses in disease ecology after adaptation or re-formulation. Through overseas collaborations, this project will also support the USDA strategy to safeguard animal and plant resources against the introduction of foreign diseases. USDA-APHIS is increasing its involvement in the One Health approach with the convergence of people, animals, and the environment, which this area of research and collaboration will support.