title: Vector species richness increases haemorrhagic disease prevalence through functional diversity modulating the duration of seasonal transmission.
abstract: Although many parasites are transmitted between hosts by a suite of arthropod vectors, the impact of vector biodiversity on parasite transmission is poorly understood. Positive relationships between host infection prevalence and vector species richness (SR) may operate through multiple mechanisms, including (i) increased vector abundance, (ii) a sampling effect in which species of high vectorial capacity are more likely to occur in species-rich communities, and (iii) functional diversity whereby communities comprised species with distinct phenologies may extend the duration of seasonal transmission. Teasing such mechanisms apart is impeded by a lack of appropriate data, yet could highlight a neglected role for functional diversity in parasite transmission. We used statistical modelling of extensive host, vector and microparasite data to test the hypothesis that functional diversity leading to longer seasonal transmission explained variable levels of disease in a wildlife population. We additionally developed a simple transmission model to guide our expectation of how an increased transmission season translates to infection prevalence. Our study demonstrates that vector SR is associated with increased levels of disease reporting, but not via increases in vector abundance or via a sampling effect. Rather, the relationship operates by extending the length of seasonal transmission, in line with theoretical predictions.
authors.affiliation: Odum School of Ecology, University of Georgia, 140 E. Green Street, Athens, GA 30602, USA.|Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, 501 D.W. Brooks Drive, Athens, GA 30602, USA.
authors.forename: Andrew W
authors.identifier: http://orcid.org/0000-0003-4080-7274
authors.initials: AW
authors.lastname: Park
authors.affiliation: Southeastern Cooperative Wildlife Disease Study (SCWDS), Department of Population Health, College of Veterinary Medicine, University of Georgia, 589 D.W. Brooks Drive, Athens, GA 30602, USA.
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Cleveland
authors.affiliation: Odum School of Ecology, University of Georgia, 140 E. Green Street, Athens, GA 30602, USA.
authors.forename: Tad A
authors.initials: TA
authors.lastname: Dallas
authors.affiliation: Southeastern Cooperative Wildlife Disease Study (SCWDS), Department of Population Health, College of Veterinary Medicine, University of Georgia, 589 D.W. Brooks Drive, Athens, GA 30602, USA.
authors.forename: Joseph L
authors.initials: JL
authors.lastname: Corn
mesh_terms: D000818:Animals; D044822:Biodiversity; D001820:Bluetongue virus / Q000502:physiology; D002519:Ceratopogonidae / Q000145:classification / Q000821:virology*; D018164:Hemorrhagic Disease Virus, Epizootic / Q000502:physiology; D054884:Host-Pathogen Interactions; D007303:Insect Vectors / Q000821:virology; D015995:Prevalence; D012088:Reoviridae Infections / Q000453:epidemiology* / Q000635:transmission / Q000821:virology*; D012621:Seasons; D015144:Southeastern United States
keywords: Parasite transmission; disease-diversity relationship; functional diversity; mathematical model; vector-borne disease