Species Interactions in a Parasite Community Drive Infection Risk in a Wildlife Population

Abstract

Web of Parasite Interactions We live under constant assault from a variety of pathogens. Pathogen exposure will be more or less harmful depending on host factors, including immune status, and, as Telfer et al. (p. 243 ; see the Perspective by Lafferty ) point out, the presence of co-infecting pathogens. In a time-series study of wild voles and four pathogens, co-infection had a larger effect on disease than any other factor. For example, infection with cowpox virus increased susceptibility and prolonged bacterial co-infections. Conversely, an ongoing infection with the bacterium Anaplasma reduced the rodents' susceptibility to the protozoan Babesia . In turn, chronic infection with Babesia limited susceptibility to the bacterium Bartonella .