Local human case of eastern equine encephalitis virus is confirmed

Published on
September 12, 2024
Health, public safety and emergencies

Ottawa Public Health (OPH) is urging residents to protect themselves against mosquito bites to reduce the risk from eastern equine encephalitis virus (EEEV) and West Nile virus (WNV). OPH has received laboratory confirmation that an Ottawa resident who died of a viral encephalitis in August 2024 tested positive for eastern equine encephalitis virus infection. According to data available, this is the first confirmed human case of eastern equine encephalitis (EEE) in Ottawa, though it is important to note that EEEV is not a reportable disease in Ontario.

Like WNV, EEEV normally cycles between wild birds and mosquitoes but can occasionally be spread to horses and, rarely, to humans through an infected mosquito’s bite. Humans do not get infected with EEEV from a horse or another human.

Although horses can be protected by a vaccine against EEEV, there is no vaccine for humans. And while human cases are rare, the disease is of concern because it can cause serious neurological disease and even death.

Preventing mosquito bites is the best way to protect yourself from EEEV and WNV. Mosquitoes remain active in both urban and rural areas at this time of year and will continue to pose a risk until heavy frosts later this fall. Residents can take the following steps to protect themselves from mosquito bites:

  • Applying a Health Canada-approved mosquito repellent containing DEET or icaridin to exposed skin and clothing (avoid applying DEET to synthetic fabrics)
  • Protecting yourself when mosquitoes are active, especially between dusk and dawn and any time you are near shady hedges or bushy or wooded areas
  • Wearing light-coloured, tightly woven, loose-fitting clothing, such as long pants, a long-sleeved shirt, shoes and socks, to protect exposed skin
  • Making sure all windows and doors in your home have screens that are in good condition

For more information about EEEV and WNV, please visit our website and see the recent public service announcement from August 21, 2024. You can also connect with OPH on Facebook, X and Instagram. 

For more information on City programs and services, visit ottawa.ca, call 3-1-1 (TTY: 613-580-2401) or 613-580-2400 to contact the City using Canada Video Relay Service. You can also connect with us through FacebookX (formerly Twitter) and Instagram