The development of a spatially resolved retrospective ensemble forecast model of West Nile virus

Abstract:

West Nile virus (WNV) is the leading cause of domestically acquired arboviral disease in the continental United States and has produced the 3 largest arboviral neuroinvasive disease outbreaks ever recorded. Aside from these substantial outbreaks, there is considerable inter-annual and geographical variation in the number of recorded human cases in the United States. As a consequence, effective allocation of public health resources is challenging and often reactive, a circumstance that highlights the need for accurate, fine spatial scale real-time forecasts of WNV transmission. Although transmission of WNV exhibits a pronounced sensitivity to a complex seasonal ecology, our ability to predict the timing, duration and magnitude of local WNV outbreaks remains limited. Here we report the ongoing development of a spatially refined model that uses ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) data to capture the variability in physical environmental factors and incorporates it into a compartmental model describing WNV transmission dynamics to provide a better understanding of mosquito infection rates. We evaluate this inference system in two unique ecosystems: Coachella Valley, California and Long Island, New York. The ECOSTRESS meteorological and hydrological indicators are included in the core model structure to better constrain WNV amplification and transmission dynamics. The inclusion of ECOSTRESS’ high spatial resolution (70 m) and highest repeat frequency (1-5 days) thermal infrared data allows us to capture changes in the micro-ecosystems. The model-inference system can then be used to better understand the spatial variability of the outbreak and estimate the relationship between zoonotic amplification and spillover human outbreaks. This work represents an initial step in the development of a statistically rigorous system for a spatially resolved real-time forecast of seasonal outbreaks of West Nile virus.