A tale of two management programs: Insights from a state-line wildlife disease outbreak

Response to infectious disease outbreaks and ongoing management actions can vary greatly across geopolitical units. Understanding relationships between management actions of governance systems within social ecological systems (SES) is important when resource units (e.g. wildlife) and users (e.g. humans) inextricably connect them. Surveillance efforts provide critical information to governance systems for diseases such as coronavirus, influenza, and ebola. However, diseases that spread rapidly across multiple SESs are coarsely managed and monitored over weeks, months, or years. Such time and spatial constraints can challenge evaluation of management actions. Assessing importance of disease management across SESs for slow-moving infectious diseases can provide rare insights about management actions. We investigated an exemplary outbreak of Chronic Wasting Disease (CWD) in white-tailed deer populations along the geopolitical border of Illinois and Wisconsin, USA. We illustrated challenges of disease management in wildlife populations along geopolitical borders, where differences in management actions of adjacent governance systems were stark and subject to sudden change. Our analysis provided evidence of abrupt change in outbreak progression following drastic changes in management actions. In addition, we showed evidence of inconsistent and highly variable outcomes of management actions along a geopolitical border when adjacent governance systems are unable to cooperatively manage across interconnected SESs. Total annual harvest in a county is a primary management action used to control CWD, where increasing harvest potentially reduces prevalence. We showed that the effects of increasing total county-level harvest on cumulative incidence of CWD were highly heterogeneous. In some counties, increasing harvest had the opposite of the intended effect.