Assessing regional differences in community composition, infection, prevalence, and human risk of tick-borne disease in California

Tick-borne diseases are the most commonly reported vector-borne diseases in North America and recent estimates of Lyme disease prevalence in the United States alone are as high as 300,000 cases annually. While the vast majority of cases in the US are reported in the upper Midwest and northeast, there are cases reported from throughout California every year, yet research on ticks and the diseases they vector has been restricted primarily to a handful of northern California counties.
Recent research has extended this work to Santa Barbara County and yielded results suggesting both that phenology of some tick species is remarkably constant over large geographic areas and that tick populations and communities can be highly variable even within relatively small geographic areas with similar habitats and climate. As a result, acaralogical risk is expected to be highly variable across the landscape.
Recent large-scale studies and surveillance efforts have been undertaken in the eastern US to characterize this variability and identify areas of high expected acaralogical risk. This type of large-scale sampling effort on the ground is crucial to our understanding of the highly geographically variable nature of ticks and tick-borne diseases and what factors are driving their emergence.
This project aims to use the UC Natural Reserve System to carry out a standardized sampling and surveillance effort applied at a larger geographical scale than has yet been undertaken in California. The goal of which is both to begin to characterize regional differences in tick communities, infection prevalence, and human risk as well as provide baseline information for the UC Reserves, and for the safety of staff and researchers working on them, that can be built upon in future studies. Specifically, data collected from the reserves will be used to ask the following questions:
1. How do tick community composition and relative abundance differ regionally in California?
H1: I. pacificus will make up a larger proportion of the community at higher latitudes and in cooler, wetter climates; the proportion will decrease as latitude decreases and as climate becomes hotter and drier where it will be dominated by Dermacentor spp.
H2: Overall tick abundance will decrease with latitude and as climate becomes more arid.
2. Are there differences in infection prevalence of I. pacificus with B. burgdorferi on a regional scale in California?
H3: Infection prevalence will be highest in the north and decrease with latitude.