The Effect of Landscape Characteristics and Climate Variables on West Virus Infection Risk in Massachusetts

Keywords: West Nile Virus, Landscape characteristics, random forest
Abstract Type: Poster Abstract

Abstract

West Nile Virus (WNV) is an arbovirus pathogen vectored by several mosquitoes whose primary reservoirs are avian wildlife, with humans acting as dead-end hosts. The WNV infection could cause illnesses ranging from fever to encephalitis and even lead to death. In Massachusetts, over 200 MNV infection cases have been reported. However, few studies focused on WNV in Massachusetts. Humans could get infected when they are bitten by WNV-infected mosquitoes. The intensity of transmission and the risk of endemic circulation of WNV depends on the abundance and distribution of infected mosquitoes. In addition, suitable areas for vectors can be affected by landscape characteristics and climate variables. The objective of this study was to evaluate the landscape characteristics more suitable for the presence of infected vectors. A set of 78 landscape composition metrics were assessed through a random forest model. We found the proximity index of the developed high-intensity areas, NDVI, the total edge of the developed medium-intensity areas, the contiguity index of cultivated crops and grasslands, and the land surface temperature to be the most important features associated with the infected-mosquito distribution in Massachusetts at the town level. As a result, we conclude that infected mosquitoes prefer clustered high-intensity urbanized areas and median-intensity developed areas with large edges. An increased land surface temperature also helps mosquito survival. Since the suitability for infected mosquitoes decreases with NDVI increases, maintaining urban and suburban forests can help mitigate the spread of WNV diseases.