title: Vector-Borne Pathogen and Host Evolution in a Structured Immuno-Epidemiological System.
abstract: Vector-borne disease transmission is a common dissemination mode used by many pathogens to spread in a host population. Similar to directly transmitted diseases, the within-host interaction of a vector-borne pathogen and a host's immune system influences the pathogen's transmission potential between hosts via vectors. Yet there are few theoretical studies on virulence-transmission trade-offs and evolution in vector-borne pathogen-host systems. Here, we consider an immuno-epidemiological model that links the within-host dynamics to between-host circulation of a vector-borne disease. On the immunological scale, the model mimics antibody-pathogen dynamics for arbovirus diseases, such as Rift Valley fever and West Nile virus. The within-host dynamics govern transmission and host mortality and recovery in an age-since-infection structured host-vector-borne pathogen epidemic model. By considering multiple pathogen strains and multiple competing host populations differing in their within-host replication rate and immune response parameters, respectively, we derive evolutionary optimization principles for both pathogen and host. Invasion analysis shows that the [Formula: see text] maximization principle holds for the vector-borne pathogen. For the host, we prove that evolution favors minimizing case fatality ratio (CFR). These results are utilized to compute host and pathogen evolutionary trajectories and to determine how model parameters affect evolution outcomes. We find that increasing the vector inoculum size increases the pathogen [Formula: see text], but can either increase or decrease the pathogen virulence (the host CFR), suggesting that vector inoculum size can contribute to virulence of vector-borne diseases in distinct ways.
authors.affiliation: School of Biological Sciences and School of Mathematics, Georgia Institute of Technology, 310 Ferst Dr, Atlanta, GA, 30332, USA. Hayriye.Gulbudak@asu.edu.
authors.forename: Hayriye
authors.identifier: 0000-0002-7859-553X
authors.initials: H
authors.lastname: Gulbudak
authors.affiliation: Department of Biology, University of Florida, 220 Bartram Hall, PO Box 118525, Gainesville, FL, 32611-8525, USA.
authors.forename: Vincent L
authors.initials: VL
authors.lastname: Cannataro
authors.affiliation: Department of Mathematical Sciences, Florida Atlantic University, Science Building, Room 234, 777 Glades Road, Boca Raton, FL, 33431, USA.
authors.forename: Necibe
authors.initials: N
authors.lastname: Tuncer
authors.affiliation: Department of Mathematics, University of Florida, 358 Little Hall, PO Box 118105, Gainesville, FL, 32611-8105, USA.
authors.forename: Maia
authors.initials: M
authors.lastname: Martcheva
mesh_terms: D000818:Animals; D005075:Biological Evolution; D003141:Communicable Diseases / Q000453:epidemiology / Q000276:immunology / Q000635:transmission; D004199:Disease Vectors; D058872:Epidemics; D054884:Host-Pathogen Interactions / Q000276:immunology; D006801:Humans; D055641:Mathematical Concepts; D008954:Models, Biological
keywords: Age-since-infection; Coevolutionary attractor; Differential equations; Immuno-epidemiological modeling; Reproduction number; Rift Valley fever; Trade-offs; Vector inoculum size; Vector-borne pathogen; West Nile virus; Within-host dynamics