Abstract

In field experiments manipulating generalist pathogens and host community composition, the presence of a highly susceptible reservoir species drove disease dynamics in multiple nonreservoir species, sometimes decreasing their abundance through apparent competition. The dynamics of generalist pathogens in multispecies host communities remain a major frontier for disease ecology. Of particular interest are how host community structure controls pathogen transmission and how disease spread feeds back to influence the host community. Pathogen spillover occurs when epidemics in a host population are driven not by transmission within that population but by transmission from a reservoir population. Here we review examples of spillover in pathogens infecting humans, domesticated animals, and crops, noting that most empirical evidence for spillover results from nonmanipulative, observational studies. We then present results from two field experiments utilizing an experimentally tractable model system of annual wild grasses and a generalist virus, the barley yellow dwarf virus. In these experiments, the presence of a highly susceptible reservoir species, Avena fatua (wild oats), greatly increased pathogen prevalence in several other species. This result demonstrates pathogen spillover and illustrates the crucial role of host community structure in controlling the dynamics of generalist pathogens. Further, pathogen spillover from A. fatua decreased the abundance of two other host species through pathogen-mediated apparent competition. Thus, our results provide experimental support for theoretical predictions of strong feedbacks between host community structure and generalist disease dynamics.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.