Ottawa resident dies from rare and deadly mosquito-borne virus

A rare and deadly mosquito-borne illness, the eastern equine encephalitis virus (EEEV), has claimed the life of an Ottawa resident, marking the city's first confirmed human case.

A rare and deadly mosquito-borne illness, the eastern equine encephalitis virus (EEEV), has claimed the life of an Ottawa resident, marking the city’s first confirmed human case.

Ottawa Public Health (OPH) issued a warning Thursday, urging residents to protect themselves from mosquito bites to reduce the risk of contracting both EEEV and West Nile Virus, which are both spread by the insect.

“OPH has received laboratory confirmation that an Ottawa resident who died of viral encephalitis in August 2024 tested positive for eastern equine encephalitis virus infection,” the statement read.

This is the first confirmed human case of EEEV in Ottawa; however, it is important to note the virus is not a reportable disease in Ontario, the statement added. That means there’s no obligation to report and track cases among provincial health officials.

The EEE virus is transmitted through the bite of an infected mosquito.

While humans and certain mammals, such as horses and llamas, can contract the disease, they do not transmit it further. There are no human vaccines or treatments for the virus.

The virus can also cause severe illness and potentially be fatal in any age group, with those under 15 and over 50 being particularly at risk, health officials warned. And while human cases are rare, the disease is of concern because it can cause serious neurological disease, OPH said.

The death rate stands between 30 and 70 per cent.