Modeling and control of environmentally transmitted pathogens
Many pathogens are able to infect hosts via the environment, without direct contact between hosts. Mathematical models are important tools to quantify disease transmission and evaluate control interventions. Environmental transmission is rarely incorporated in mathematical models of disease transmission. Our project objective is to develop and analyze models that include environmental transmission. As a result of your project, we have developed a framework to classify pathogens based on the role that non-host environments play in the pathogen lifecycle. We have shown under what conditions and types of pathogen lifecycle, different types of models are suitable or not to represent environmental transmission. We have developed two new modeling approaches to represent environmental transmission, one presenting transmission in a network, and other describing transmission as a queueing problem. To develop networks for both host-to-host and environment-to-host networks, we created a software package that takes location data and transforms the data into information on contacts that can influence organisms that cause infectious diseases [include link to the subprojects contact networks].
We have also built models to quantify transmission of Clostridioides difficile in hospitals and Escherichia coli transmission in cattle. Our models indicated that interventions that decrease patient susceptibility such as vaccines or antimicrobial stewardship were more impactful in reducing the number of infection cases than interventions blocking transmission-including environmental cleaning.