2nd Place: Investigating spatiotemporal distributions of West Nile virus in sentinel chicken coops during an active transmission season in Florida

West Nile virus (WNV) is a mosquito borne disease that has been of veterinary and public health concern since its introduction to Florida in 2001. The two main mosquito vector species for WNV in Florida are Culex quinquefasciatus and Culex nigripalpus. Since natural WNV amplification occurs in multiple wild avian species, sentinel chickens are used as a cost-efficient method for Florida arbovirus surveillance. Data created from the arboviral tests performed in the sentinel chickens result in weekly reports to inform mosquito management activities; however, few analyses have investigated site-level spatiotemporal distributions of these data across all participating Florida Mosquito Control Districts (FMCD). Our aim was to quantify the underlying spatiotemporal structure of WNV in Florida at 187 sentinel chicken coop sites across 36 weeks during the 2018 sampling season using spatiotemporal Gaussian Markov Random Fields (GMRFs) executed in the INLA package in R. Results indicated that the weekly GMRF plots captured the majority of the transmission season with WNV seroconverted chickens occurring in distinct foci in the Panhandle and northeastern Florida in the second week of July. Peak activity occurred in October throughout the entire state, which may be correlated to peak abundances of Cx. nigripalpus across Florida. Active transmission occurred into December, highlighting the importance of year-round surveillance to capture the full transmission cycle. GRMFs created with site level data are a valuable tool for understanding WNV transmission dynamics, serve as a foundation for future environmental investigations, and can provide new information toward improved vector management strategies.