Monitoring urban planning in the context of climate change and emerging tick-borne diseases
UPTick is a three-year study to enhance our understanding of how urban changes affect human risk from Lyme and other tick-borne diseases. We will conduct surveillance for tick-borne pathogens in ticks and small mammals at sites that represent different stages of urban development and connection to greenspace across the study areas. These methods are simple, humane, and unobtrusive.
The study is taking place among neighbourhoods in western Ottawa, Ontario - namely Stittsville, Kanata, and Carp. Experiencing significant expansion of black-legged tick (Ixodes scapularis) populations, Ottawa was first declared an at-risk area for Lyme disease in 2017. During the past three years, our team has identified environmental risk for Lyme disease in numerous areas of the city in close proximity to greenspace.
Through these surveillance activities, we will enhance the ability to detect and respond to disease threats by:
(1) Identification of at-risk locations to allow better targeting of interventions;
(2) Development of best practices for healthy urban planning to mitigate the emergence of tick-borne diseases in Canadian communities; and
(3) Strengthening surveillance efforts in residential zones to inform public health action.
Public Health Ontario reports that Eastern Ontario is considered an area of significant Lyme disease emergence. This follows the trend that the range of black-legged ticks (Ixodes scapularis), the species that transmits the bacterium causing Lyme disease, has expanded northward in eastern Canada due in large part to climate and environmental changes.
Surveillance in previous years has identified the Ottawa region as broadly suitable for black-legged tick establishment. Sites with high tick density and infection rates have been identified in several areas of the city, including in close proximity to suburban neighbourhoods bordered by greenspace.
Ottawa is experiencing rapid expansion; it surpassed a population of 1 million people in June 2019. Population growth, land use change, and climate change are all expected to contribute to the continued emergence of tick populations and Lyme disease risk. Urban expansion, which is often characterized by the expansion of residential subdivisions into natural areas where transmission of tick-borne pathogens among animals exists, may place more people at risk of Lyme disease and other tick-borne infections.
We identified regions of the city with recent or ongoing urban development or greening initiatives occurring across the seven sectors of Ottawa's Greenbelt. The list of potential regions was refined in consultation with partners from the National Capital Commission, Ottawa Public Health, and the City of Ottawa's Planning Division.
Neighbourhoods were ultimately selected to reflect different levels of forest fragmentation and stages of landscape change, while considering the presence of black-legged tick populations. Tick population establishment was determined with models informed by active surveillance for ticks from 2017 to 2019.
To focus project activities on regions at varying stages of urban development, four neighbourhoods were selected: (1) Shirley Bay - Kanata Lakes; (2) Stoney Swamp - Stonehaven expansion; (3) Stittsville neighbourhood - Upper Poole Creek corridor; and (4) Carp Hill Wetland Complex.