Fluid Mechanics and Epidemiology
Fluid Mechanics and Epidemiology
We use ideas from transport, fronts, and pattern formation to explain how mobility reshapes epidemics—showing that a small fraction of traveling infected individuals can control outbreak speed and spatial structure.
Why mobility matters in epidemics
Most epidemic models emphasize local infection dynamics—how fast infection spreads within a community. But real outbreaks unfold across space, driven by movement between communities.
In our work, we call these highly mobile infected individuals geographical spreaders. Their role is analogous to “fast transport pathways” in fluid systems: rare, but disproportionately influential.
A mechanistic picture: fronts, waves, and hotspots
A small mobile fraction (often 1–10%) can seed distant communities and reorganize outbreak geometry.
Mobility changes the effective transport process, accelerating the epidemic front beyond what local transmission alone predicts.
Long-range seeding can generate waves and hotspots—structured patterns that emerge even without large changes in infection rate.
What this framework enables
- Quantifying how mobility controls outbreak speed (front propagation)
- Identifying when small mobile subpopulations dominate spread
- Explaining waves/hotspots as transport-driven pattern formation
- Guiding interventions that target movement pathways, not only transmission rates
Representative Publication
- Li, S., Henriquez, C., & Katul, G. The role of geographical spreaders in infectious pattern formation and front propagation speeds. Physica D: Nonlinear Phenomena, 440, 133460. (Add DOI / link if you want it shown here.)