Climate Change Fuels Rise in Tick-Borne Diseases in Canada

The changing climate in Canada is increasingly contributing to the rise of tick-borne diseases, particularly Lyme disease, as public health experts warn of a potential health crisis. According to Heather Coatsworth, Chief of Field Studies at the National Microbiology Laboratory in Winnipeg, "Climate change in Canada is happening at a much more accelerated rate than we see in parts of the rest of the world" (Coatsworth, 2025).

As temperatures rise, ticks that transmit various diseases are expanding their geographical range, particularly in regions such as Manitoba, Saskatchewan, Alberta, and British Columbia. Coatsworth noted that these eight-legged organisms require specific heat and humidity levels to thrive, and the warming climate facilitates their proliferation. Traditional hotspots for blacklegged ticks, which are responsible for Lyme disease, continue to be Ontario, Quebec, and Nova Scotia.

The Public Health Agency of Canada (PHAC) has reported a dramatic increase in Lyme disease cases since it began monitoring in 2009. In 2024 alone, preliminary figures indicate there were 5,239 reported cases, a stark contrast to the mere 144 cases documented at the start of monitoring. Estimates suggest that if current trends continue, Canada could see around half a million Lyme disease cases in the next 25 years (PHAC, 2024).

Janet Sperling, President of the Canadian Lyme Disease Foundation, emphasized the need for heightened awareness regarding tick-borne illnesses. "A lot of doctors have been trained to believe that Lyme disease is not a risk in areas like Alberta," she stated, calling for improved education for healthcare providers regarding the evolving risks posed by ticks.

The increase in tick populations has not only led to more Lyme disease cases but has also ushered in other lesser-known tick-borne diseases such as anaplasmosis, babesiosis, and the Powassan virus. Coatsworth highlighted that anaplasmosis, once relatively rare, has seen a significant rise, with over 700 cases reported last year compared to only 10 to 50 cases annually when monitoring began in 2012.

Symptoms of Lyme disease can often mimic those of other illnesses, including fever, chills, fatigue, and joint pain, with the characteristic bull's-eye rash appearing in only about 70% of cases (PHAC, 2024). Meanwhile, anaplasmosis can cause cough and abdominal pain, and the Powassan virus, while less common, can lead to severe neurological symptoms.

Treatment for Lyme disease and anaplasmosis typically involves antibiotics, whereas babesiosis requires anti-parasitic medications. Unfortunately, there is currently no specific treatment for the Powassan virus, and care is largely supportive (Coatsworth, 2025).

Preventive measures remain crucial as the threat from ticks grows. Public health physician Dr. Mayank Singal from the BC Centre for Disease Control recommends wearing long sleeves and pants, using insect repellent, and performing full-body tick checks after outdoor activities (Singal, 2025).

As the climate continues to warm, the implications for public health could be profound. Experts suggest that ongoing monitoring and public education are vital to combat the rising tide of tick-borne diseases. The 2025 summer season will require heightened vigilance for outdoor enthusiasts as tick populations become more prevalent across Canada.