Speaker
Description
We develop and analyze a temperature-driven, stage-structured model for the transmission of Borrelia burgdorferi (Lyme disease) involving the tick vector Ixodes scapularis and multiple host classes. The model is formulated as a system of nonlinear ordinary differential equations incorporating seasonal forcing, life-stage transitions, and host-dependent feeding dynamics.
We compare two formulations: one with density-based host contact and one with stage-dependent host preference. Using numerical simulations, we examine how variations in reservoir-competent and reservoir-incompetent host populations influence both tick abundance and infection dynamics.
Our results demonstrate that host preference significantly alters system behavior and leads to a threshold-type phenomenon: a dilution effect occurs at low densities of reservoir-competent hosts, while an amplification effect emerges at higher densities. These findings highlight the role of host composition in shaping disease dynamics and provide a mechanistic explanation for contrasting outcomes reported in the ecological literature.
