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DETECTING AND MITIGATING THE ENVIRONMENTAL IMPACT OF FECAL PATHOGENS ORIGINATING FROM CONFINED ANIMAL FEEDING OPERATIONS: REVIEW
Citation:
ROGERS, S. AND J. R. HAINES. DETECTING AND MITIGATING THE ENVIRONMENTAL IMPACT OF FECAL PATHOGENS ORIGINATING FROM CONFINED ANIMAL FEEDING OPERATIONS: REVIEW. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-06/021 (NTIS PB2006-109780), 2005.
Impact/Purpose:
To present a literature review on the potential impact of fecal pathogens originating from animal agriculture in the United States.
Description:
This report presents a review of literature regarding the potential impact of fecal pathogens originating from animal agriculture in the United States. Livestock production and dairy operations continue their trend toward larger and more concentrated facilities. These operations produce vast quantities of manure, much of which is used as a fertilizer for crops or spread onto land with little or no treatment. Land-applied manures can contaminate food crops or be washed from the land into groundwater or nearby streams affecting recreational and drinking water quality far from their origin. Animal manures contain an array of pathogenic organisms including viruses, bacteria, and parasites. Contact with manure pathogens in the air, soil, water or contaminated food may result in infections and outbreaks of disease manifesting as mild gastrointestinal upsets to severe illness or even death, especially in children, the elderly, and the immunocompromised. Dosing animals with antimicrobials for growth promotion and prophylaxis encourages the growth of more virulent strains of pathogens that may be resistant to many human-use medicines, resulting in limited treatment options for infected individuals. The cost of food and waterborne disease outbreaks in the United States due to zoonoses of livestock animal origin may be in the billions of dollars each year. The key to understanding the public health risks posed by manure pathogens lies in understanding how they may be transmitted between hosts and vectors, survive outside of animal hosts in different milieus, and how they may be transported through the air, soil, and water in the environment. Survival of manure pathogens after excretion from livestock animals can range from hours to years depending on several factors not limited to properties of the specific pathogen, temperature, desiccation, pH, exposure to solar radiation, and nutrient status of the environment. Once in the environment, pathogens can move far from their origin depending on the mode and rate of application of manures to fields, rainfall, runoff management practices, tile drainage, soil properties, and more. Heavy rainfall has been shown to increase the potential for outbreaks of disease. Other factors relevant to the transmission, survival, and transport of manure pathogens from livestock operations are discussed in the review. A stronger focus on three key research areas would improve biosecurity and human health and welfare in the United States: (1) better methods are needed for rapid detection of pathogens in different milieus, (2) more reliable methods are needed to identify the source of fecal contamination in polluted environments, and (3) improved use of manure treatment practices and a better understanding of how common runoff management practices restrict the movement of pathogens are needed to reduce their release to the environment. A review of works relevant to these three key areas is presented along with a summary of ongoing research within the U.S. EPA and other federal agencies. Siginificant work is needed to develop better methods for microbial analysis and to measure the effectiveness of management practices as they are actually used on the landscape. Important collaboration is expected to grow between the agencies to address the issue of pathogenic organisms emanating from CAFOs. Finally, research recommendations are presented to help focus future work on the most important topics.