Mapping the Habitat Suitability of West Nile Virus Vectors in Southern Quebec and Eastern Ontario, Canada, with Species Distribution Modeling and Satellite Earth Observation Data

Abstract

Transmission of vector-borne diseases (VBDs) relies on the presence of their vectors. Good knowledge of their habitat distribution could inform of their presence and then the potential transmission risk. In Canada, West Nile virus (WNV), a VBD transmitted by mosquitoes of the Culex genus to birds, humans, and other mammals, was first reported in 2002. Since then, human cases have been reported every year. To reduce the health burden of the disease and to guide the vector control efforts, this work aims to provide a map of habitat suitability of the main vectors of WNV, Culex pipiens-restuans, in southern Quebec and eastern Ontario at 30 m spatial resolution. Landsat 8-OTI/TIRS images were combined with existing geographical data to characterize vegetated and paved areas in urban and peri-urban areas and to create a land use land cover map related to environmental determinants of Culex pipiens-restuans. Landscape metrics were calculated to characterize the neighborhood environment. They were used with 1008 presence sites of the vectors to build species distribution models with Maxent, a model based on the maximum entropy principle, and to predict habitat suitability for Culex pipiens-restuans in the study area. The performance of the models was very good, with a mean area under the curve of 0.92 and a continuous Boyce index of 0.97. A habitat suitability map of the whole study area was created for Culex pipiens-restuans. The resulting map and environment analysis highlight the importance of the edge of vegetation and mixed or paved areas for the bio-ecology of Culex pipiens-restuans.