Stocking Density and Homogeneity, Considerations on Pandemic Potential

Abstract

Zoonotic pathogens, an increasing threat to human health, typically originate in the wild but spill over to humans from domestic animals because of the high contact with them. Industrial farming involves an increased number of animals of a single species per given area. Such high stocking density facilitates pathogen transmission. This speeds evolution and also offsets the natural tendency of pathogens to trend toward mildness. On the other hand, close contact reduces transmission dependence on host mobility and thus could favor virulence. Forestalling this problem requires understanding opportunities for spillovers and evolution created by animal farming technologies and human-animal-ecosystem interactions. This manuscript considers two important risk factors of intensive animal farming, stoking density and homogeneity, to inform practices that could stop the next pandemic at its source.