Multi-species, climate-driven and landscape-based cellular difference equation model for west Nile virus: Toward an agent-based model of west Nile virus spread

The objective of this study is to design and implement an efficient data-driven Agent-Based Model (ABM) of West Nile Virus (WNV) spread, considering highly-mobile humans with a high level of heterogeneous properties. The undeniable value of such an ABM is in simulating and assessing virtually all epidemiological scenarios and prevention strategies. This chapter proposes a Cellular Difference Equation (CDiffE) model for adoption in WNV-ABMs. The proposed CDiffE Model includes multiple species of birds and humans as hosts for the spread of WNV in Southern Manitoba. The migration patterns of different bird species, nocturnal biting activities of Culex tarsalis mosquitoes, daily temperature and rainfall, and land cover impact are incorporated into the model. WNV-related parameters for different bird species are estimated according to biological studies on avian viremia. The proposed CDiffE updates on an hourly step in order to act as an environment for a comprehensive agent-based model of WNV spread among peripatetic humans. In general, the model predicts mosquito distribution across the province effectively well. The mosquito population trends within the model over 15 weeks in approximately 30 communities of Manitoba has Pearson and Spearman correlation values of approximately 60% compared with the real-world mosquito trap data. The difference equations are principally much faster than commonly used differential equation models. While the whole system is designed from an agent-based modelling perspective at a cellular level, it exhibits biologically compatible behaviour at the macro-level scale. The geographical output of the current model can be considered a decision support tool for public health policymakers by providing risk maps of mosquito densities. In varying the model parameters, some theoretically verified as well as counter-intuitive findings were observed.