The Analysis of eTick Submission in Ontario

Abstract

Purpose: Ixodes scapularis, also known as the eastern blacklegged tick, is associated with the vector-borne Lyme disease in North America. With climate change, warming temperatures have increased the number of areas suitable for ticks, and contributed to the expansion of tick species in Canada. The purpose of this project was to identify recent trends in tick range expansion and species diversity in Ontario by analyzing 2019 to 2022 data from the web-based tick surveillance platform, eTick.ca. Method: The eTick.ca web platform allows the public to submit tick photos for identification. We extracted data from the tick submissions for Ontario between mid-2019 to 2022 including information on the type of species, host types, travel history, and location. Microsoft Excel was used to generate distribution tables and graphs of tick submissions by species, month/year and host type for Ontario. Geographic Information Systems (ArcGIS) and SaTScan software were used to identify spatial clusters of tick submissions adjusting for the human population size using Ontario census subdivisions. Result: A total of 14,611 tick photo submissions were recorded between 2020 to 2022, excluding those with a history of recent travel. The year 2021 had the highest number of submissions (n=7339). Dermacentor species comprised the majority of submissions (n=9498, 65%), followed by I. scapularis (n=4810, 33%) and other species (n=303, 2%) between 2020-2022. Ticks were most commonly discovered on a human host (n=10,084), followed by animal hosts (n=3485), and free in environments (n=1042). Additionally, the majority of species were found in the adult stage (n=12,821, 88%), followed by unknown (n=1539, 10%) and immature stages (n=251, 2%). Clusters of I. scapularis were present in the Eastern, Central, and Southern Ontario regions, while clusters of Dermacentor sp. were present in Southern and Central Ontario regions. Conclusion: Spatial and temporal variations in tick submissions in Ontario were identified over the 3.5 year period since the implementation of eTick in the province. Data from eTick can be used to identify hotspots of human-tick exposure.