Population Dynamics of Viruses and Microbes

This chapter discusses how virus–host interactions affect population dynamics. Models of virus–host interactions suggest that long-term persistence between a single virus population and a single host population is possible. Population dynamics models demonstrate that one potential effect of a viral infection is to shift a community from bottom-up to top-down control. One hallmark of top-down control is a decrease in host abundance with virus addition. A second hallmark of top-down control is an increase in resource concentration with virus addition. Virus–host population dynamics can exhibit oscillations. These oscillations are typified by phase lags between peaks in population abundances of host and virus, in which the host peak precedes the viral peak. The period of oscillations is often much longer than the latent period time between viral infection and lysis.