Abstract
Coinfection events, the simultaneous infection of hosts by multiple pathogens, may alter the course of disease(s) at the population level. Here, we utilize a system of Drosophila and the associated Drosophila C virus (DCV) and Drosophila X virus (DXV) to examine how viruses may interact to alter the dynamics of mortality and viral transmission. We find that coinfection reduced the effects of the viruses on host mortality. The main effect of these viruses appears to be on greatly reducing expected variance in mortality between small populations exposed to the viral treatments rather than on cumulative mortality between populations over experimental time. We also show that the effects of coinfection on transmission rates and infection severity are non-additive in small populations exposed to a single infectious donor. These studies provide a framework for the understanding and development of a tractable empirical system for modeling viral coinfection at the population level.