title: From within-host interactions to epidemiological competition: a general model for multiple infections.
abstract: Many hosts are infected by several parasite genotypes at a time. In these co-infected hosts, parasites can interact in various ways thus creating diverse within-host dynamics, making it difficult to predict the expression and the evolution of virulence. Moreover, multiple infections generate a combinatorial diversity of cotransmission routes at the host population level, which complicates the epidemiology and may lead to non-trivial outcomes. We introduce a new model for multiple infections, which allows any number of parasite genotypes to infect hosts and potentially coexist in the population. In our model, parasites affect one another's within-host growth through density-dependent interactions and by means of public goods and spite. These within-host interactions determine virulence, recovery and transmission rates, which are then integrated in a transmission network. We use analytical solutions and numerical simulations to investigate epidemiological feedbacks in host populations infected by several parasite genotypes. Finally, we discuss general perspectives on multiple infections.
authors.affiliation: Laboratoire MIVEGEC (UMR CNRS 5290, IRD 224, UM), 911 Avenue Agropolis, B.P. 64501, 34394 Montpellier Cedex 5, France mircea.sofonea@ird.fr.
authors.forename: Mircea T
authors.initials: MT
authors.lastname: Sofonea
authors.affiliation: Laboratoire MIVEGEC (UMR CNRS 5290, IRD 224, UM), 911 Avenue Agropolis, B.P. 64501, 34394 Montpellier Cedex 5, France.
authors.forename: Samuel
authors.initials: S
authors.lastname: Alizon
authors.affiliation: Laboratoire MIVEGEC (UMR CNRS 5290, IRD 224, UM), 911 Avenue Agropolis, B.P. 64501, 34394 Montpellier Cedex 5, France.
authors.forename: Yannis
authors.initials: Y
authors.lastname: Michalakis
mesh_terms: D000818:Animals; D050936:Basic Reproduction Number; D060085:Coinfection / Q000453:epidemiology / Q000209:etiology / Q000469:parasitology; D006790:Host-Parasite Interactions; D006801:Humans; D008954:Models, Biological; D059208:Parasite Load; D010272:Parasitic Diseases / Q000453:epidemiology / Q000209:etiology* / Q000469:parasitology; D014774:Virulence
keywords: basic reproduction number; co-infection; epidemiology; public goods; spite; superinfection