Psychosocial impacts of a mouse plague and ongoing psychological stress

In 2020-21, parts of eastern Australia experienced a severe mouse plague, estimated to have caused up to AUD$1 billion worth of damage. Yet, the mental health impacts of such a pest plague are not empirically known. The present study sought to quantify and model the psychosocial impacts of the 2021 mouse plague and measure ongoing psychological stress two years post-plague, to provide insights into social impacts and mental wellbeing during a significant biosecurity incursion. An online survey (N = 1,691) measured key psychosocial impact metrics included psychological traits, emotional states (depression, disgust, embarrassment), perceptions of social impacts (response costs, attitudes), support (social, government), and perceived threat of future plague. A partially mediated path model accounted for 74% of variability observed in perceived severity of impacts and ongoing psychological stress. Severity of impacts was predominantly influenced by perceived response costs , negative mood states (i.e. depression ) and disgust elicited by the odour of mice. The most influential direct predictors of ongoing psychological stress were depressive symptoms at the time of the plague, and concerns that a future mouse plague would be dangerous or catastrophic to oneself. This study provides empirical insights into both acute social impacts during a significant pest incursion, as well as ongoing psychological stress. Social impacts are rarely measured or modelled; yet, these factors are critically important in understanding the effect of severe pest incursions on communities whose livelihoods often depend on the agricultural sector.