I leaned against my car, swatting at a mosquito that had landed on my arm. The late spring sun warmed my face as I stood in the parking lot of the Grey Bruce Health Unit. It was my third visit this season to the region, where public health workers have been quietly expanding their surveillance program for vector-borne diseases.
“We’ve been seeing changes in the tick populations over the last decade,” explained Marla Thompson, an environmental health specialist who agreed to show me some of their collection sites. “What used to be rare—finding a blacklegged tick—is now becoming more common. And that means more potential for Lyme disease transmission.”
As we walked along a trail at the edge of a wooded area, Thompson dragged a white flannel cloth across the tall grass—a technique called “flagging” that’s used to collect ticks for testing. This simple but effective method is part of a comprehensive surveillance program that has expanded across Grey Bruce counties this year.
The Grey Bruce Health Unit has intensified its vector surveillance efforts as warming temperatures extend the active season for disease-carrying insects and arachnids. Public health officials are now monitoring 12 fixed sites throughout the region, up from eight locations last year.
“Climate change is altering habitats and lengthening the seasons when these vectors are active,” Dr. Ian Arra, Medical Officer of Health for Grey Bruce, told me during an interview at his office. “We’re finding ticks earlier in spring and later into fall. The geographic range of many species is also expanding northward.”
Vector-borne diseases—those transmitted by mosquitoes, ticks, and other arthropods—have been steadily increasing across Canada. According to Public Health Ontario, confirmed Lyme disease cases in the province have more than doubled over the past five years, with similar trends observed for West Nile virus and other infections.
Grey Bruce officials are particularly concerned about several diseases: Lyme disease, carried by blacklegged ticks; West Nile virus and Eastern Equine Encephalitis, both transmitted by mosquitoes; and the emerging threat of anaplasmosis, another tick-borne bacterial infection that causes flu-like symptoms.
The surveillance program combines active monitoring with public reporting. Residents who find ticks on themselves can submit them to local health units for identification and testing. Last year, the Grey Bruce Health Unit received over 400 tick submissions, with approximately 14% identified as the blacklegged variety that can carry Lyme disease.
“Each tick tells us something about what’s happening in our environment,” Thompson explained as she carefully transferred a tick from the flannel cloth into a collection vial. “When we track changes in populations over time, we can identify high-risk areas and focus our prevention efforts.”
Back at the health unit’s environmental laboratory, I watched as staff sorted mosquito samples collected from traps set throughout the region. The insects were carefully identified by species, then pooled for testing. The process requires patience and precision—skills that Sarah Clemens has honed over her eight years as a vector surveillance technician.
“We’re seeing mosquito species that were once rare in this region,” Clemens said, adjusting her microscope. “Aedes albopictus, the Asian tiger mosquito, has been spotted in southern Ontario. It’s not established here yet, but we’re watching carefully because it can transmit several viruses.”
The surveillance work extends beyond simply tracking vectors. The health unit correlates their findings with human case data, environmental conditions, and climate patterns to develop predictive models. This approach allows them to issue targeted public advisories when risk levels increase.
Community engagement forms another crucial component of the program. The health unit partners with conservation authorities, provincial parks, and local municipalities to monitor public spaces and educate visitors about protection strategies.
In a classroom at Peninsula Shores District School in Wiarton, I observed a health educator teaching students how to identify different tick species and perform proper tick checks. The children practiced the “tick check dance”—a playful routine designed to help them remember to check their bodies after outdoor activities.
“Prevention is still our best tool,” said Karen Miller, a public health nurse who leads community outreach efforts. “Teaching people—especially children—how to protect themselves creates habits that last a lifetime.”
The Grey Bruce surveillance program exemplifies a proactive approach to public health that other regions might consider emulating. Rather than reacting to disease outbreaks, officials are working to identify and mitigate risks before they impact human health.
For residents like Michael Jameson, a retired teacher who contracted Lyme disease in 2020, these efforts provide reassurance. “I was gardening when I got bit—never even saw the tick,” Jameson told me when we met at a local coffee shop. “The rash appeared about a week later, but I didn’t connect it to Lyme until the joint pain and fatigue set in.”
Jameson’s experience with delayed diagnosis is common. The Health Unit reports that many vector-borne diseases present with vague, flu-like symptoms that patients and healthcare providers may not immediately recognize. By the time Jameson received appropriate treatment, he had developed chronic symptoms that still affect him today.
“That’s why this surveillance work matters,” Dr. Arra emphasized. “When we understand where the risks are highest, we can alert both the public and healthcare providers to be vigilant.”
As I drove away from Grey Bruce that evening, I noticed several roadside signs warning visitors about tick habitats. The messages were simple but effective: “Ticks Are Here. Protect Yourself.” It struck me that this balance of awareness without alarmism exemplifies good public health communication—informative without inducing panic.
With vector-borne diseases expected to continue their northward expansion as temperatures rise, the work being done in Grey Bruce offers valuable lessons for communities across Canada. By combining scientific surveillance with community education and healthcare provider training, public health officials are building resilience against emerging threats.
The mosquito bite on my arm had faded to a small red bump—a minor annoyance today, but a reminder of the invisible risks we navigate in our changing environment. For the dedicated team in Grey Bruce, each bite prevented represents a small victory in a larger battle to protect public health in a warming world.
