Associations between wildlife observations, human-tick encounters and landscape features in a peri-urban tick hotspot

Abstract

Zoonotic disease vectors, their wildlife hosts, and the surrounding landscape interact in complex ways that vary spatially, temporally and with anthropogenic change. Ticks (Acari: Ixodidae) are one of the most important vectors of human disease globally but managing the risk of tick bites in urban areas requires a detailed understanding of these complex vector-host-environment relationships at multiple spatial scales. Extensive knowledge gaps of these interactions in Australia limits options for managing ticks and exacerbates human-wildlife conflict. To address this, we used an online survey to determine the potential drivers of human-tick encounters operating at the local, yard scale and at the broader, landscape scale in a peri-urban area of Australia. We explored the relationships between reported tick encounters in yards and yard traits, host sightings (yard-scale) and broader landscape traits (landscape-scale). We found that sightings of potential hosts such as long-nosed bandicoots (Perameles nasuta) and brush-turkeys (Alectura lathami), and broader landscape traits such as distance to wet sclerophyll forest, were important predictors of reported tick encounters. Yard traits such as garden mulching and leaf litter cover showed no relationships with tick encounters. However, garden mulching and the absence of pets were predictors of frequent bandicoot sightings in yards. Mulching over 20m2, moderate to dense leaf litter cover on lawns, and living adjacent to bush were predictors of frequent brush-turkey sightings in yards. Our results suggest that residents may be able to reduce tick encounter risk by making yards less attractive to potential hosts. The observed relationships provide a critical foundation for field studies that can determine underlying mechanisms and inform appropriate tick management in urban environments. Graphical abstract: [Figure not available: see fulltext.].