1. Jeanette A. Thurston-Enriquez
Manure-borne Pathogens: Impact of Animal Agriculture on Microbial Water Quality
Jeanette A. Thurston-Enriquez
USDA-ARS

2. Livestock Manure Increase in CAFOs 500 million tons/year in U.S.
26 million tons/yr in NE

3. Public Health and Animal Waste
Animal waste agents
Infectious
bacteria, viruses, protozoa
Chemical
nutrients, endocrine disrupters, antimicrobials

4. Manure-borne Pathogens of Concern
Protozoan Parasites
Pathogenic Bacteria
Fungi
Viruses
Antibiotic Resistant Bacteria

5. In order to determine the human health impact of manure-borne pathogens we need to evaluate:
Occurrence
Survival/Persistence
Dissemination/Transport
Manure, Manure Management Systems, & Surrounding Environment: Water, Air, Soil

6. Other Health-Related Microorganisms
Fecal Indicator Microorganisms
What?
Traditionally, bacteria of fecal origin
Total and fecal coliforms
Escherichia coli
Why?
Indicators of fecal contamination
Recreational and drinking water quality regulations
Faster, cheaper, easier detection

7. Waterborne Disease in the U.S.
12-20 outbreaks/yr
x higher
~900,000 cases of waterborne microbial infections
Up to 900 deaths
>70% in >55 yrs

8. Water Sources Affecting Public Health
Drinking
Recreational
Irrigation
Foodborne

9. Contamination Routes RUNOFF Wildlife Agriculture Groundwater Urban and
Well head impacts
Urban and
storm water
WWTP
overflow
Septic tank
leakage
Agriculture
Recreation
Wildlife
Groundwater
Infiltration
percolation
Discharge

10. Manure Dissemination Land application Aerosol generation
Leakage or overflow from storage lagoons or treatment ponds
Runoff from feed yards, manure-applied land, pasture land, etc.

11. Well head impacts

12. Outbreak Source: Animal Ag.
Walkerton, 2001
Land-applied cattle manure
Agricultural runoff to groundwater supply
Escherichia coli O157:H7 & Campylobacter
>2000 cases
7 fatalities

13. Contributing Factors for Environmental Persistence and Transmission of Enteric Pathogens
High numbers shed in feces
Increased survival
Low infectious dose
Increased resistance to disinfection/treatment
Multiple routes of transmission
Animal and human infections

14. Potential Routes of Human Exposure to Pathogens
Waterborne
Drinking and recreational water
Foodborne (can be related to waterborne)
Direct contact, irrigation water, ingestion of contaminated produce
Direct Contact
Aerosol Transmission
Transport to water supplies or food crops
Inhalation of aerosols
Contact

15. Possible Pathogen Transmission by Aerosols
Direct transmission or deposition onto food crops, fomites, or water
Biosolids Land
Application
Livestock Spray Irrigation

16. Barriers Against Waterborne Disease
Drinking water and wastewater treatment
Disinfection & Filtration
Surface water monitoring/Source water protection
Point-of-use devices—disinfect/filter
Protection of recreational waters
Contaminant monitoring
Designation of specific uses

17. Agriculture: Limiting Microbial Transport

18. Limiting Microbial Transport: Manure Storage & Treatment
Holding Ponds & Lagoons
Compost

19. Limiting Microbial Transport: Aerosols
Land
application
Pen scraping
Top spray vs. drop spray
Keep tractor speed low; scrape moist soil
Low wind speed
Wind direction

20. Limiting Microbial Transport: Vegetated Filter Strips

21. Microbial Reduction Prior to Land Application: Constructed Wetlands
Alternative waste management and treatment technology
Bacterial reduction: >80 % (prior to plant establishment)
Protozoan parasite reduction: >60 % (prior to plant establishment)

22. Manure-borne Pathogen Information Gaps
Environmental Loading
Environmental Fate
Treatment Effectiveness
Alternative Treatments/Tech.
Detection Methods
Viability
Sensitivity
Specificity
Emerging Pathogens
**Risk Assessments
Requires above information

24. Questions/Comments?