Speaker
Description
Eastern equine encephalitis virus (EEEV) is a deadly arboviral pathogen with 30% severe case fatality. EEEV exhibits pronounced 2–3 year cyclical outbreak patterns in the northeastern United States, linked to shifts in mosquito feeding preferences between hatchyear and adult avians. An age-structured vector-host model incorporating differential feeding patterns of Culiseta melanura mosquitoes on European Starlings and American Robins was developed. Sensitivity analysis revealed mosquito biting rate as a dominant driver in transmission, with avian infectivity and exposure playing secondary roles. Pairing machine learning algorithms with SHAP analysis on parameter sets identified parameter hierarchies that govern cyclic transmission. Adult avian mortality was identified as the key parameter underlying cyclic and stable transmission patterns. SHAP further revealed these patterns to be grounded on opposite sides of the same epidemiological mechanism. Stable endemics emerge from demographic stability paired with transmission optimization, while cyclic endemics emerge from demographic instability paired with minimal transmission optimization. Numerical simulations illustrated critical threshold dynamics for exposure towards young, where heightened hatch-year exposure triggers demographic instability responsible for observed 2–3 year cycles, while balanced exposure leads to stable endemics. These mechanisms provide a foundation for targeted surveillance and control interventions.
