Within-host parasite dynamics, emerging trade-off, and evolution of virulence with immune system.
Virulence is an evolutionary paradox because parasites never benefit from their host's death. The adaptive explanation of virulence is classically based upon the existence of physiological constraints that create a trade-off between parasites' epidemiological traits (virulence, transmissibility, and clearance). Here we develop an epidemiological model where infections are dynamic processes and we demonstrate how these dynamics generate a trade-off between emerging epidemiological parameters. We then study how host's immune strength modifies this trade-off and hence influences virulence evolution. We found that in acute infections, where parasites are engaged in a race with immune cells, immunity restrains more the duration of the infection than its intensity. As a consequence parasites evolve to provoke more virulent but shorter infections in strongly immunized hosts.
André
Jean-Baptiste
JB
Laboratoire Génome, Populations, Interactions, Adaptation, UM2-IFREMER-CNRS UMR 5000, Université Montpellier II-CC 063, Bâtiment 13, RdC, Place Eugène Bataillon, 34095 Montpellier Cedex 5, France. jbandre@crit.univ-montp2.fr
Ferdy
Jean-Baptiste
JB
Godelle
Bernard
B
D005075:Biological Evolution; D006790:Host-Parasite Interactions; D007113:Immunity, Innate; D008954:Models, Biological; D014774:Virulence