ABSTRACT
Arthropod-borne viruses (arboviruses) threaten the health of humans, livestock, and wildlife. West Nile virus (WNV), the world's most widespread arbovirus, invaded the United States in 1999 and rapidly spread across the county. Although the ecology of vectors and hosts are key determinants of WNV prevalence across landscapes, the factors shaping local vector and host populations remain unclear. Here, we used spatially-explicit models to evaluate how three land-use types (orchards, vegetable/forage crops, natural) and two climatic variables (temperature, precipitation) influence the prevalence of WNV infections and vector/host distributions at landscape and local spatial scales. Across landscapes, we show that orchard habitats were associated with greater prevalence of WNV infections in reservoirs (birds) and incidental hosts (horses), while increased precipitation was associated with fewer infections. At local scales, orchard habitats increased the prevalence of WNV infections in vectors (mosquitoes) and the abundance of mosquitoes and two key reservoir species, the American robin and the house sparrow. Thus, orchard habitats benefitted WNV vectors and reservoir hosts locally, creating focal points for the transmission of WNV at landscape scales in the presence of suitable climatic conditions.
Subject(s)
Agriculture/statistics & numerical data , Bird Diseases/epidemiology , Culex/physiology , Horse Diseases/epidemiology , Insect Vectors/physiology , West Nile Fever/veterinary , West Nile virus/physiology , Animals , Bird Diseases/transmission , Birds/virology , Climate , Female , Horse Diseases/transmission , Horses/virology , Humans , Prevalence , Spatial Analysis , West Nile Fever/epidemiology , West Nile Fever/transmissionABSTRACT
The emergence of West Nile virus in the United States renewed vigilance for mosquito-borne diseases and rejuvenated mosquito surveillance activities in Washington State. As part of these activities, the Zoonotic Disease Program, Washington Department of Health, and the United States Army Center for Health Promotion and Preventive Medicine-West collaborated to produce this revision of the distribution of mosquitoes in Washington State. Data from these organizations, the US Air Force, and county surveillance records, as well as published literature and mosquito collections, were used to develop this statewide mosquito distribution checklist.
