Human and Animal Pathogens in Manure

Fecal wastes from domestic animals, wildlife and humans are applied to the soil surface and to varying extents are incorporated into the soil. These fecal wastes can also enter water systems by direct contamination of the water or through seepage or surface runoff. Humans contaminate water sources through poorly processed sewage effluents, malfunctioning septic tanks and seepage from sanitary landfills. Domestic and wild animals contaminate water by defecation in unprotected surface water, through runoff and as a result of seepage of water through soil that contains an excessive amount of animal feces. A wide variety of pathogenic viruses, bacteria and parasites may be found in the feces of wild and domestic animals and humans. Also, nonpathogenic bacteria and parasites are found in large numbers in the feces of animals as well as soil and water. Only a small number of animal pathogens in feces, water and soil have the potential to infect humans and domestic animals (Table 1). These are the pathogens that are of great concern to the public, who are usually exposed to these animal pathogens through consumption of fecal contaminated food or water.