Psychosocial impacts of a mouse plague and ongoing psychological stress.

A path model of psychosocial impacts from the 2021 mouse plague accounted for 74% of variability in perceived severity of impacts and ongoing psychological stress.

• Online survey with N=1,691 participants was conducted.
• The model was described as 'partially mediated.'
• Key psychosocial metrics included psychological traits, emotional states, perceptions of social impacts, support, and perceived threat of future plague.
• The study measured both acute impacts during the plague and ongoing psychological stress two years post-plague.

Perceived severity of impacts during the mouse plague was predominantly influenced by perceived response costs, depressive mood states, and disgust elicited by the odour of mice.

• Response costs (perceived costs of responding to the plague) were identified as a key predictor of severity.
• Negative mood states, specifically depression, were a significant predictor of perceived severity.
• Disgust specifically elicited by the odour of mice was identified as a distinct predictor of perceived severity.
• Embarrassment was also measured as an emotional state but was not listed among the predominant predictors of severity.

The most influential direct predictors of ongoing psychological stress two years post-plague were depressive symptoms at the time of the plague and concerns about a future mouse plague being dangerous or catastrophic.

• Ongoing psychological stress was measured approximately two years after the 2021 mouse plague.
• Depressive symptoms experienced during the plague period were a primary direct predictor of later psychological stress.
• Perceived threat of a future plague—specifically concerns that it 'would be dangerous or catastrophic to oneself'—was the other most influential direct predictor.
• These findings suggest both acute emotional responses and future threat perceptions contribute to longer-term psychological burden.

The 2020-21 mouse plague in eastern Australia caused an estimated up to AUD$1 billion worth of damage, yet mental health impacts had not previously been empirically quantified.

• The plague affected parts of eastern Australia in 2020-21.
• Economic damage was estimated at up to AUD$1 billion.
• The authors note that 'the mental health impacts of such a pest plague are not empirically known' prior to this study.
• The study was framed as addressing a gap in empirical knowledge about psychosocial impacts of significant biosecurity incursions.

Social impacts of pest incursions are rarely measured or modelled despite their critical importance to communities dependent on the agricultural sector.

• The authors state 'Social impacts are rarely measured or modelled.'
• The study included perceptions of social impacts such as response costs and attitudes as key metrics.
• Both social support and government support were measured as part of the psychosocial impact framework.
• The authors emphasize these factors are 'critically important in understanding the effect of severe pest incursions on communities whose livelihoods often depend on the agricultural sector.'