Pliant pathogens: Estimating viral spread when confronted with new vector, host, and environmental conditions

Pathogen spread rates are determined, in part, by the performance of pathogens under altered environmental conditions and their ability to persist while switching among hosts and vectors.

To determine the effects of new conditions (host, vector, and nutrient) on pathogen spread rate, we introduced a vector-borne, viral plant pathogen, Barley Yellow Dwarf Virus PAV (BYDV-PAV) into hosts, vectors, and host nutrient supplies that it had not encountered for thousands of viral generations. We quantified pathogen prevalence over the course of two serial inoculations under the new conditions. Using individual level transmission rates from this experiment, we parameterized a dynamical model of disease spread and projected spread across host populations through a growing season.     

A change in nutrient conditions (increased supply of phosphorus) reduced viral transmission whereas shifting to a new vector or host species had no effect on infection prevalence.  However, the reduction in th...