title: Spatial heterogeneity, host movement and mosquito-borne disease transmission.
abstract: Mosquito-borne diseases are a global health priority disproportionately affecting low-income populations in tropical and sub-tropical countries. These pathogens live in mosquitoes and hosts that interact in spatially heterogeneous environments where hosts move between regions of varying transmission intensity. Although there is increasing interest in the implications of spatial processes for mosquito-borne disease dynamics, most of our understanding derives from models that assume spatially homogeneous transmission. Spatial variation in contact rates can influence transmission and the risk of epidemics, yet the interaction between spatial heterogeneity and movement of hosts remains relatively unexplored. Here we explore, analytically and through numerical simulations, how human mobility connects spatially heterogeneous mosquito populations, thereby influencing disease persistence (determined by the basic reproduction number R0), prevalence and their relationship. We show that, when local transmission rates are highly heterogeneous, R0 declines asymptotically as human mobility increases, but infection prevalence peaks at low to intermediate rates of movement and decreases asymptotically after this peak. Movement can reduce heterogeneity in exposure to mosquito biting. As a result, if biting intensity is high but uneven, infection prevalence increases with mobility despite reductions in R0. This increase in prevalence decreases with further increase in mobility because individuals do not spend enough time in high transmission patches, hence decreasing the number of new infections and overall prevalence. These results provide a better basis for understanding the interplay between spatial transmission heterogeneity and human mobility, and their combined influence on prevalence and R0.
authors.affiliation: University of Puerto Rico-Río Piedras, Department of Biology, San Juan, PR, USA.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Acevedo
authors.affiliation: Dartmouth College, Department of Mathematics, Hanover, NH, USA.
authors.forename: Olivia
authors.initials: O
authors.lastname: Prosper
authors.affiliation: Statistical and Applied Mathematical Sciences Institute, Durham, NC, USA.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Lopiano
authors.affiliation: University of Florida, Department of Biology, Gainesville, FL, USA.
authors.forename: Nick
authors.initials: N
authors.lastname: Ruktanonchai
authors.affiliation: University of Florida, Department of Biology, Gainesville, FL, USA.
authors.forename: T Trevor
authors.initials: TT
authors.lastname: Caughlin
authors.affiliation: University of Florida, Department of Mathematics, Gainesville, FL, USA.
authors.forename: Maia
authors.initials: M
authors.lastname: Martcheva
authors.affiliation: University of Georgia, Odum School of Ecology, Athens, GA, USA.
authors.forename: Craig W
authors.initials: CW
authors.lastname: Osenberg
authors.affiliation: Department of Epidemiology and Malaria Research Institute, John Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
authors.forename: David L
authors.initials: DL
authors.lastname: Smith
mesh_terms: D000818:Animals; D050936:Basic Reproduction Number; D003141:Communicable Diseases / Q000453:epidemiology / Q000635:transmission*; D003198:Computer Simulation; D009033:Culicidae / Q000502:physiology*; D006790:Host-Parasite Interactions; D006801:Humans; D009068:Movement; D015995:Prevalence