Understanding and Assessing Impacts
Lyme disease is the most common tick-borne illness in Canada and cases are increasing due to blacklegged tick population growth, due in part to climate change. Over the past few decades, as blacklegged ticks have been spreading northward into new territory, reported cases of Lyme disease in Canada have grown from about 150 in 2009 to over 2,000 in 2017. Longer, hotter summers and more mild winters associated with climate change is increasing the ticks’ rates of survival, growth and reproduction, and allowing them to survive and establish populations in areas where they previously couldn’t, and increase their numbers where they were already established. Longer summers also mean a longer season where ticks are active and people are outdoors – increasing the window of opportunity for the two to meet. Additionally, climate change is expected to increase the range, abundance, and activity of rodent, bird, and deer hosts that carry the disease. In response to demand by clinicians and with current and projected increases in Lyme disease cases in Canada, the Centre for Effective Practice’s (CEP’s) developed the Lyme Disease Tool to help family physicians and other health care providers understand that Lyme disease is a treatable illness that is increasing in incidence in Canada.