Tick-borne disease (TBD) incidences are rising globally, highlighting the need for effective prevention strategies that consider the ecological context of disease transmission. We analyzed the relationship between human prevalence of four TBDs in 22 counties in the eastern U.S. and various ecological and climatic factors. Babesiosis showed a negative relationship with mean annual temperature, while ehrlichiosis exhibited no clear associations with the investigated variables. Anaplasmosis prevalence was positively linked to nymphal tick densities, with the abundance of competent hosts mediating the relationship between prevalence and small mammal richness. Lyme disease prevalence was positively associated with densities of ticks and reservoir hosts, while negatively related with precipitation, temperature, and small mammal richness. In terms of effect size, the negative effect of temperature was the most important predictor for babesiosis, anaplasmosis and Lyme disease. We expand on previous works on the dilution effect in Lyme disease by linking reservoir hosts, tick density, and human cases at the regional scale. Our findings underscore the importance of ecological context in designing effective strategies for disease management, suggesting that TBD intervention efficacy may vary based on tick and host dynamics.

Current climate change is disrupting biotic interactions and eroding biodiversity worldwide. However, species sensitive to drought, high temperatures and climate variability might persist in microclimatic refuges, such as leaf shelters built by arthropods. We conducted a distributed experiment across an 11,790 km latitudinal gradient to explore how the importance of leaf shelters for terrestrial arthropods changes with latitude, elevation and underlying climate. Our analyses revealed leaf shelters to be key facilitative elements for the diversity of arthropods. Predator diversity and overall biomass within shelters increased with local drought and temperature variability, regardless of latitude and elevation. In contrast, shelter usage by herbivores increased with abundance of predators on those same plants and in wetter climates. Projected increase in climatic variability and drought in certain geographic regions is therefore likely to enhance the importance of biotic refuges, especially for predators, in mitigating the impact of climate change on species persistence.