Modelling multi-species parasite transmission.
Some models are presented for the dynamics of a host population with two parasite species. The models differ in two main aspects: whether they include direct competition among parasites and whether the analysis is based on some approximation and which one. If the analysis is not constrained by a priori assumptions about parasite distributions, it is found that species coexistence is very unlikely without some kind of direct competition among parasites; on the other hand, coexistence generally occurs when inter-specific competition is lower than intraspecific, similarly to standard theory for free-living species. If hosts differ in their predisposition to infection, but not in an identical way towards the two parasite species, then species coexistence becomes feasible even if inter-specific competition is as strong as intraspecific; in this case, coexistence becomes easier as the variance in predisposition increases. These models do not yield universal predictions for patterns of parasite distributions; an analysis of the mechanisms of interaction in each specific system is necessary for that.
Pugliese
Andrea
A
Dipartimento di Matematica, Università di Trento Via Sommarive 14 38050 Povo, Italy. pugliese@science.unitn.it
D000818:Animals; D005298:Fertility; D006790:Host-Parasite Interactions / Q000502:physiology*; D006801:Humans; D008954:Models, Biological; D017711:Nonlinear Dynamics; D010271:Parasites / Q000472:pathogenicity / Q000502:physiology; D010272:Parasitic Diseases / Q000635:transmission*; D013045:Species Specificity