Anaplasmosis could become increasingly common in Quebec, in part because climate change is extending the period of activity of ticks, accelerating their life cycle and thereby prolonging human exposure to ticks. The upward trend has caught the attention of a research team at the University of Montreal’s School of Veterinary Medicine. This summer, professors Catherine Bouchard, Cécile Aenishaenslin, Patrick Leighton and Jean-Philippe Rocheleau, together with Raphaëlle Audet-Legault, a veterinarian and a master’s in epidemiology at UdeM, are conducting research to determine which species of small wild mammals are reservoirs of anaplasmosis. and therefore contribute to human transmission of the disease. “The tick is like a used syringe,” Bouchard explained. “Say he bit a mouse for his previous meal. Suppose the bacteria responsible for the anaplasmosis were circulating in the blood stream of the mouse. Now, when the tick bites a man, it infects him with the blood of the mouse. If the mouse carried a zoonotic variant, the human would contract the disease.’
Mapping distribution
With the help of the City of Bromont, the Estrie Department of Public Health and the Regional Municipality of Brome-Missisquoi County, the team will capture rodents of different sizes (mice, chipmunks, squirrels) around Bromont over the summer to see which have the highest prevalence. of reincarnation. Veterinarians will also collect ticks in the field to measure the percentage of infected ticks in the area. Half of the sampling sites are in areas where there have been human cases and the other half where there have been none. “We want to compare the proportion of infected small mammals close to human outbreaks and further away, in addition to determining whether the prevalence of infection varies by species,” said Audet-Legault. “We are interested in the degree to which the circulation of the bacterium is restricted,” added Bouchard. “I would not be surprised if there is no difference between the sites near human cases and the others. We may find that there are more human cases where there is a higher population density, but the disease is just as present elsewhere. So residents should exercise due vigilance.”
Education for prevention
In the face of the explosion of human reincarnation cases, efforts to promote safe behaviors in exposed populations — such as full-body clothing and routine self-checks after going outdoors — should be stepped up, Bouchard said. Education efforts should be directed not only at residents but also at health care professionals, who should look beyond Lyme disease when diagnosing patients from high-risk areas. Anaplasmosis is not easily diagnosed because symptoms are generally non-specific and mild, such as fever, chills, headache and muscle aches. Unlike Lyme disease, a tick bite does not leave redness on the skin. Audet-Legault also pointed out that most people infected with anaplasmosis are bitten near their homes while gardening or doing similar activities. “In eastern cities, many people have houses on the mountainside, under a canopy of mature trees. So they literally live in the tick’s habitat. We need to increase our awareness efforts as all residents are potentially at risk.” As a first step, the research team met with Bromont residents to present their research project. Interactive workshops are planned in the summer.
