Eastern equine encephalitis (EEE) has already killed one person.
Quebec doctors are calling for caution, as the mosquito season is far from over despite the end of summer.
“The threat could still exist and people should be especially careful, especially if they are going to do activities like camping in the wilderness,” said infectious disease specialist Dr. Donald Vinh.
Transmission of the virus to humans is rare, but it can be fatal.
The New England resident died of complications from the virus in August.
Dr Vinh explained that the virus can cause serious damage to people’s nervous systems.
“The person may present not only with fever and headache, but also confusion, convulsions or seizures. It can even cause the person to fall into a coma or, unfortunately, cause death.”
The incubation period of the virus varies from three to ten days and begins with flu and cold symptoms.
Although cases in humans are rare, it is not uncommon to find them in horses.
“In Quebec, the most significant outbreak was discovered in horses during the first epidemic in 1992,” said Miarisoa Rindra Rakotoarinia, advisor to the Institut de santé publique du Québec (INSPQ).
The last Quebec case reported in horses dates back to 2008.
Health Canada has reported four human cases of EEE in Ontario, the most recent being reported in 2022.
The species of mosquitoes that spread the virus, which is caught by biting birds that carry it, are found in regions such as Lanaudière and the Eastern Townships, Rakotoarinia reported.
However, the insects could spread to other regions as the weather warms.
“With climate change, we expect more flooding and rising temperatures, which is favorable to the development of mosquitoes,” she said.
About 5% of infected people develop a neuroinvasive form of the disease, and some are at higher risk, according to Dr. Vinh.
“People over 65, yes, but also young children, infants and toddlers,” Dr. Vinh said. “Certainly people who are immunocompromised can also have the most severe form of the disease.”
The doctor said the virus has been known to cause epidemics in eastern North America for 100, even 200 years.
There is currently no vaccine or medical treatment for this viral infection.
“But you still need to see a doctor because we can give them medical care to monitor and treat any complications that may arise from this infection,” Dr. Vinh stressed.
In terms of prevention, he recommends the use of insect repellents, mosquito nets and wearing loose-fitting, long-sleeved shirts and pants.
“We must not forget that birds and mosquitoes travel and do not respect borders.”
