Waterborne, abiotic and other indirectly transmitted (W.A.I.T.) infections are defined by the dynamics of free-living pathogens and environmental reservoirs

Miles D. Miller-Dickson; Victor A. Meszaros; Francis Baffour-Awuah; Salvador Almagro-Moreno; C. Brandon Ogbunugafor

In this study, we propose a framework-the waterborne, abiotic and other indirectly transmitted pathogen paradigm (WAIT)-for modeling infectious diseases where transmission is dictated by an interaction between hosts and dynamic multi-compartment environmental reservoirs. We use it to explore two very different modern epidemics of significant public health consequence: cholera and hepatitis C virus. We first establish it through a simple form, an elementary adapted SIR formulation, and highlight how it modifies fundamental properties of epidemics such as the basic reproductive number (R 0 ). We then build mathematical models to explore cholera and HCV disease dynamics. We demonstrate how the integrated framework highlights potentially overlooked properties of these systems, and highlights potential avenues for intervention. The model is compatible with existing canon in epidemiology, and can accommodate theory in the ecology and evolution of infectious disease. For example, the "curse of the pharaoh hypothesis," which predicts that pathogens with high free-living survival can be more virulent [78] , can be modeled on a population scale using the WAIT framework. In addition, its careful treatment of environmental dynamics makes it amenable to questions regarding how changes in climate, social policy, or behavior may influence the spread of disease.