Mountains, Valleys, and Rivers: The Transmission of Raccoon Rabies Over a Heterogeneous Landscape

Landscape features may serve as either barriers or gateways to the spread of certain infectious diseases, and understanding the way geographic structure impacts disease spread could lead to improved containment strategies. Here, we focus on the space-time diffusion of a raccoon rabies outbreak across several states in the Eastern United States. While focusing on pattern, we move toward closer links between pattern and process by considering statistical estimation of local pattern features to gain insight oil landscape influences oil the underlying process. Specifically, we quantify the impact that landscape features, such as mountains and rivers, have on the speed of infectious disease diffusion. This work combines statistical modeling with operations in a geographic information system (GIS) to link observed patterns of disease diffusion with local landscape values. We explore three analytic approaches. First, we use spatial prediction (kriging) to provide a descriptive pattern of the spread of the virus. Second, we use Bayesian areal wombling to detect barriers for infectious disease transmission and examine spatial coincidence with potential features. Finally, we input landscape variables into a hierarchical Bayesian model with spatially varying coefficients to obtain model-based estimates of their local impacts on transmission time in Counties.