An Ottawa resident has passed away after being infected by a mosquito-borne virus. CTV News
Ottawa has confirmed its first human case of Eastern equine encephalitis virus (EEEV), a mosquito-borne illness, following the death of a resident in August. Ottawa Public Health (OPH) revealed that the individual had been suffering from viral encephalitis, which was later found to be caused by EEEV.
Eastern equine encephalitis, like the more familiar West Nile Virus, typically circulates between wild birds and mosquitoes. However, in rare cases, it can spread to horses and humans through mosquito bites. It's important to note that humans cannot contract EEEV from horses or other people. Unfortunately, there is currently no vaccine available for humans to protect against this virus.
This summer, in August, the Ontario Ministry of Agriculture, Food, and Agribusiness reported another instance of EEEV—this time in a horse in the Ottawa area. The infected horse, a 15-year-old Thoroughbred gelding, exhibited symptoms such as difficulty walking, lethargy, and an unresponsive posture. The condition worsened overnight, and the horse was euthanized. Officials noted that the horse had not been vaccinated against EEEV.
In humans, the symptoms of EEEV are not always immediately apparent. They often begin with fever, headaches, and respiratory issues, followed by vomiting. Severe cases can lead to brain inflammation, or encephalitis, which can be fatal. Ottawa's case is currently the only confirmed instance of human EEEV in Canada during the 2024 mosquito season, which runs from May to October. According to the Public Health Agency of Canada (PHAC), this death is the first human EEEV case reported this year.
PHAC expressed condolences to the affected family while reassuring the public that human cases of EEEV are extremely rare in Canada. Since 2016, only three locally acquired human cases have been confirmed in the country, with the most recent one occurring in 2022. In addition to human cases, eight instances of EEEV in horses have been recorded nationwide.
Ottawa Public Health has issued a strong advisory urging residents to protect themselves from mosquito bites, given the risks posed by both West Nile Virus and EEEV. To reduce the likelihood of infection, health officials recommend applying mosquito repellents approved by Health Canada, such as those containing DEET or icaridin. People should take extra precautions during the peak mosquito activity times, particularly from dusk to dawn. Wearing light-coloured, loose-fitting clothing that covers the skin can also help ensure that windows and doors are properly screened.
As of this summer, two human cases of West Nile Virus have also been confirmed in Ottawa. Earlier in July, another case of EEEV was reported when a horse in Lanark County tested positive for the virus.
