a day ago
First case of tick-borne Rocky Mountain spotted fever discovered in Quebec
In the latest sign of climate change affecting human health in Quebec, authorities on Monday confirmed the first case in the province of Rocky Mountain spotted fever — a potentially life-threatening tick-borne illness more commonly found in southern regions of the United States that is now making its way into Canada amid rising temperatures.
'We are aware of the situation and are monitoring it closely to obtain more information about the presence of this disease in Quebec,' a Health Ministry spokesperson told The Gazette. 'In the meantime, the best way to protect yourself against ticks is to avoid being bitten by taking preventive measures ' like wearing pants and long sleeves when venturing outdoors and using mosquito repellant.
Dr. Alex Carignan, a microbiologist and infectious diseases specialist at the CIUSSS de l'Estrie, took to social media to inform the public about the case.
'Recently, we identified a case of Rocky Mountain spotted fever (RMSF) infection in the Eastern Townships,' Carignan said in a post on X. 'This is the first case of transmission in Quebec. Fortunately, the patient responded well to doxycycline (antibiotic) treatment. This infection causes high fevers, a distinctive rash, and can lead to death if not properly managed.
'We knew that this bacterium (Rickettsia rickettsiae) would arrive in the coming years, but unfortunately it showed up a bit earlier than expected,' Carignan added.
Infections transmises par les tiques: une nouvelle venue au Québec.
Récemment, nous avons identifé un cas d'infection à la fièvre pourprée des montagnes rocheuses ("rocky mountain spotted fever") acquis en Estrie. Il s'agit du premier cas de transmission au Québec.…
— Alex Carignan (@carignan_alex) August 18, 2025
Dr. Isaac Bogoch, an infectious diseases physician and scientist at the University Health Network in Toronto, noted that RMSF was 'recently also seen in dogs in Long Point, Ont.,' on the north shore of Lake Erie.
'RMSF is an uncommon but very serious tick-borne infection,' Bogoch added on X.
RMSF is not to be confused with Lyme disease, which is an infection that can also be contracted from tick bites. In contrast with RMSF's local rarity, Lyme disease has now become endemic on the island of Montreal. Yet only a decade ago, Lyme disease was considered somewhat of a rare occurrence in Montreal.
The outlook for RMSF is good if treated early. Still, the death rate from RMSF hovers between five and 10 per cent in the U.S., even with treatment, according to the Cleveland Clinic.
A 2019 study by Quebec and Manitoba researchers warned that the risk of tick-borne diseases in Canada was expected to rise in the coming years because of climate change.
'Climate warming and other environmental changes have contributed to the expansion of the range of several tick species into higher latitudes in North America,' the authors concluded in the study.
'As temperatures increase in Canada, the environment becomes more suitable for ticks and the season suitable for tick activity lengthens, so tick-borne diseases are likely to become more common in Canada. In addition to Lyme disease, four other tick-borne diseases (TBDs) have started to emerge and are likely to increase: Anaplasmosis; Babesiosis; Powassan virus; and Borrelia miyamotoi disease. Increased temperature increases the survival and activity period of ticks, increases the range of both reservoir and tick hosts (e.g. mice and deer) and increases the duration of the season when people may be exposed to ticks.'
And now authorities can add Rocky Mountain spotted fever to that list.
Climate change is not just responsible for the spread of TBDs into Canada harming human health. Lingering smoke from wildfires in northern Quebec and the Prairie provinces — which are becoming more common because of human-induced climate change creating ever-hotter and drier weather conditions — is resulting in more respiratory and other illnesses.
In July, the Association québécoise des médecins pour l'environnement sounded the alarm about the deleterious long-term effects on Quebecers' health due to their chronic exposure to polluted air.
And during the heat wave last week, Montreal public health officials confirmed three heat-related deaths and two cases of heatstroke. On Aug. 11, Montreal set a new temperature record of 35.1 C at Trudeau airport.
This story was originally published
