West Nile Virus Transmission Suitability Modeling for Culex pipiens via Temperature and Humidity

Abstract

West Nile Virus (WNV) is the leading cause of mosquito-borne disease in the United States, yet predicting its transmission remains a significant challenge for public health officials. Many studies use correlative statistical models to predict disease cases using temperature and humidity, but accessible mechanistic approaches that simulate mosquito behavior traits can capture more of the transmission process. This study adapts an existing R-language package, the Mosquito-borne Viral Suitability Estimator (MVSE), which was created to model Aedes aegypti mosquito transmission of dengue, and tunes it to Culex pipiens transmission of WNV. Equations for mortality, biting rate, and incubation period were updated, and Vapor Pressure Deficit (VPD) was used in place of Relative Humidity to better approximate dehydration stress on mosquitos. Our Culex-specific customizations of the model improved correlations with annual disease cases at the county level, particularly in locations with higher Culex pipiens habitat suitability. For West Nile Neuroinvasive Disease (WNND), the correlation between MVSE performance (Spearman's rho for WNND incidence and our custom Index P) and probability of Culex pipiens presence was 0.48 (p = 0.03). These results demonstrate that incorporating trait sensitivity to temperature and VPD results in species-specific models that may be effective in informing WNV disease prevention efforts.