Journal of Mathematical Biology

, Volume 27, Issue 2, pp 179-190

First online:

A competitive exclusion principle for pathogen virulence

  • H. J. BremermannAffiliated withDepartment of Biophysics and Department of Mathematics, University of California
  • , H. R. ThiemeAffiliated withDepartment of Mathematics, Arizona State University

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For a modified Anderson and May model of host parasite dynamics it is shown that infections of different levels of virulence die out asymptotically except those that optimize the basic reproductive rate of the causative parasite. The result holds under the assumption that infection with one strain of parasite precludes additional infections with other strains. Technically, the model includes an environmental carrying capacity for the host. A threshold condition is derived which decides whether or not the parasites persist in the host population.

Key words

Co-evolution Commensalism Evolution of virulence Myxomatosis Extinction Persistence Multi-strain epidemic model Stable endemic equilibrium