The presence of indicator bacteria, hepatitis E virus (HEV), and numerous bacterial pathogen genes increased following precipitation-induced runoff events in streams draining adjacent land surfaces in Iowa where swine manure was recently applied.
Runoff from both land application of animal manure and agricultural tile drainage are possible transport pathways for bacterial, fungal, protozoan, and viral pathogen to surface waters. Animal manure harbors not only animal-specific pathogens but also zoonotic pathogens (HEV, Campylobacter jejuni) capable of infecting humans.
This study simultaneously examined the environmental occurrence of indicator bacteria, HEV, and other livestock-related bacterial, protozoan, and viral pathogens in relation to periods of swine manure application in a basin (South Fork Iowa River) with extensive swine production (around 840,000 hogs in the 78,000-ha watershed) and in an out-of-basin control (Walnut Creek) that had similar soils and land use but no known livestock or swine manure application. Scientists determined the presence and abundance of HEV and other microbiological contaminants from water and bottom sediment collected from 6 stream sites in central Iowa during 2011 and 2012 and swine manure from two swine operations in 2011.
Increased concentrations of indicator bacteria after manure application that exceeded Iowa's State bacteria water quality standards suggest that swine manure contributes to diminished water quality and may pose a risk to human health. Additionally, the occurrence of HEV and numerous bacterial pathogen genes for Escherichia coli, Enterococcus spp., Salmonella sp., and Staphylococcus aureus in both manure samples and in corresponding surface water following periods of manure application provides evidence that such swine manure applications may play an important role in the spreading of zoonotic pathogens to the surrounding environment.
This study detected HEV, pathogen gene markers from bacteria, and several antibiotic resistance genes that can pose mild to serious health risks to swine, humans, and wildlife. This research provides the foundational understanding required for future assessment of the risk to environmental health from livestock-related zoonotic pathogen exposures. This information could also be important for maintaining swine herd biosecurity and protecting the health of wildlife near swine facilities. Although this study focused on runoff of land-applied manure as a source of microbial pathogens to surface waters, the results could also apply to accidental manure releases due to equipment failures, manure storage overflow, severe weather events, or accidents with manure-transporting equipment.
In order to fully understand the environmental health risks and options for disease prevention, further research is needed to
- better understand the persistence and survival of manure-related zoonotic pathogens in water and sediment,
- assess the risk to animals and humans from manure-related zoonotic pathogens,
- ascertain manure management techniques that can reduce zoonotic pathogen load to the environment, and
- ascertain the scope of manure spills in the United States to better understand the risk of exposure of humans, livestock, and wildlife.
The study was funded by the U.S. Geological Survey (USGS) Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology) and the U.S. Department of Agriculture Agricultural Research Service.
See below for science related to this research.
Food Resources Lifecycle Integrated Science Team
Gestodene Affects Fish Reproductive Behavior in Laboratory Exposure Study
Bacterial Pathogen Genes in Streams related to Animal Type and Hydrologic Conditions
Iodinated Disinfection Byproducts found in Dairy-Impacted Wastewaters and Streams
Potential Exposure to Bacteria and Viruses Weeks after Swine Manure Spill
Biosolids, Animal Manure, and Earthworms: Is There a Connection?
- Overview
The presence of indicator bacteria, hepatitis E virus (HEV), and numerous bacterial pathogen genes increased following precipitation-induced runoff events in streams draining adjacent land surfaces in Iowa where swine manure was recently applied.
Sources/Usage: Public Domain.A U.S. Geological Survey analyst performs DNA extractions on enriched cultures of water from the study area. Once the DNAwas extracted it was used to detect pathogen gene markers using polymerase chain reaction (PCR). Photo Credit: Heather Johnson, USGS. Runoff from both land application of animal manure and agricultural tile drainage are possible transport pathways for bacterial, fungal, protozoan, and viral pathogen to surface waters. Animal manure harbors not only animal-specific pathogens but also zoonotic pathogens (HEV, Campylobacter jejuni) capable of infecting humans.
This study simultaneously examined the environmental occurrence of indicator bacteria, HEV, and other livestock-related bacterial, protozoan, and viral pathogens in relation to periods of swine manure application in a basin (South Fork Iowa River) with extensive swine production (around 840,000 hogs in the 78,000-ha watershed) and in an out-of-basin control (Walnut Creek) that had similar soils and land use but no known livestock or swine manure application. Scientists determined the presence and abundance of HEV and other microbiological contaminants from water and bottom sediment collected from 6 stream sites in central Iowa during 2011 and 2012 and swine manure from two swine operations in 2011.
Increased concentrations of indicator bacteria after manure application that exceeded Iowa's State bacteria water quality standards suggest that swine manure contributes to diminished water quality and may pose a risk to human health. Additionally, the occurrence of HEV and numerous bacterial pathogen genes for Escherichia coli, Enterococcus spp., Salmonella sp., and Staphylococcus aureus in both manure samples and in corresponding surface water following periods of manure application provides evidence that such swine manure applications may play an important role in the spreading of zoonotic pathogens to the surrounding environment.
Sources/Usage: Public Domain.A typical pen format for swine in many Iowa animal feeding operations. Photo Credit: Kent Becker, USGS. This study detected HEV, pathogen gene markers from bacteria, and several antibiotic resistance genes that can pose mild to serious health risks to swine, humans, and wildlife. This research provides the foundational understanding required for future assessment of the risk to environmental health from livestock-related zoonotic pathogen exposures. This information could also be important for maintaining swine herd biosecurity and protecting the health of wildlife near swine facilities. Although this study focused on runoff of land-applied manure as a source of microbial pathogens to surface waters, the results could also apply to accidental manure releases due to equipment failures, manure storage overflow, severe weather events, or accidents with manure-transporting equipment.
In order to fully understand the environmental health risks and options for disease prevention, further research is needed to
- better understand the persistence and survival of manure-related zoonotic pathogens in water and sediment,
- assess the risk to animals and humans from manure-related zoonotic pathogens,
- ascertain manure management techniques that can reduce zoonotic pathogen load to the environment, and
- ascertain the scope of manure spills in the United States to better understand the risk of exposure of humans, livestock, and wildlife.
The study was funded by the U.S. Geological Survey (USGS) Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology) and the U.S. Department of Agriculture Agricultural Research Service.
- Science
See below for science related to this research.
Food Resources Lifecycle Integrated Science Team
The team studies the movement of toxicants and pathogens that could originate from the growing, raising, and processing/manufacturing of plant and animal products through the environment where exposure can occur. This information is used to understand if there are adverse effects upon exposure and to develop decision tools to protect health.Gestodene Affects Fish Reproductive Behavior in Laboratory Exposure Study
Short-term laboratory exposure of adult fathead minnows to the human contraceptive progestin, gestodene (GES), at environmentally relevant concentrations induced rapid and negative effects on reproductive health and suggests that wild fish may be similarly affected.Bacterial Pathogen Genes in Streams related to Animal Type and Hydrologic Conditions
A U.S. Geological Survey (USGS) study elucidates the influence of animal type and environmental variables on bacterial pathogen occurrence in streams under typical watershed conditions.Iodinated Disinfection Byproducts found in Dairy-Impacted Wastewaters and Streams
Iodinated disinfection byproducts were found at stream locations downstream from treated discharge from wastewater treatment plants that receive dairy waste and in the wastewaters directly from dairy facilities.Potential Exposure to Bacteria and Viruses Weeks after Swine Manure Spill
Manure spills may be an underappreciated pathway for livestock-derived contaminants to enter streams. Scientists from the U.S. Geological Survey (USGS) and Johns Hopkins Bloomberg School of Public Health studied an Iowa stream after the release of a large volume of swine manure (a manure spill). The scientists observed an increase in viruses and bacteria, which have the potential to cause human or...Biosolids, Animal Manure, and Earthworms: Is There a Connection?
Animal manure and biosolids, the solid byproduct of wastewater treatment, often are applied to agricultural crops to provide nutrients for plant growth and to improve the quality of soil. Earthworms studied in agricultural fields where manure and biosolids were applied have been found to contain organic chemicals from household products and manure. Earthworms continuously ingest soils and may... - Publications