OPH confirms 1st case of West Nile virus in a human this year

OttawaThe first human case of West Nile virus has been confirmed in Ottawa, as well as the first case of eastern equine encephalitis virus in a horse, according to a news release Wednesday from Ottawa Public Health.Horse also diagnosed with eastern equine encephalitis virusCBC News · Posted: Aug 27, 2025 2:44 PM EDT | Last Updated: 1 hour agoMost people who contract the mosquito-borne virus do not develop symptoms, according, but around 20 per cent can experience flu-like effects and less than one per cent may develop a serious illness. (AP/Rick Bowmer)The first human case of West Nile virus (WNV) has been confirmed in Ottawa, according to a news release Wednesday from Ottawa Public Health (OPH).OPH also said a horse had been infected with Eastern Equine Encephalitis virus (EEEV), another mosquito-borne illness that killed one person in Ottawa last year. The agency is advising residents to protect themselves against mosquitoes, and offered a few suggestions: Apply mosquito repellent containing DEET or icaridin to exposed skin and clothing. Wear light-coloured and tightly woven but loose-fitting clothes that cover your skin. Ensure all the window screens in your home are in good repair. Remove standing water sites like bird baths and wheelbarrows, or empty them once a week. Cover rain barrels.  EEEV occasionally infects horses and rarely infects humans through mosquitoes, but humans cannot be infected by a horse, OPH wrote. It is a rare disease with only four known human cases in Ontario, but it can cause serious neurological disease and death. Most people infected with WNV do not develop symptoms, according to OPH, but around 20 per cent can experience flu-like symptoms and less than one per cent may develop a serious illness. The risk of serious illness increases with age. Two other human cases of WNV, one confirmed and one probable, were noted by the South East Health Unit on Aug. 21. Across Ontario, there have been 21 human cases of WNV in 2025 as of Sunday, according to Public Health Ontario. In 2024 there were 13 human cases of WNV in Ottawa and 87 in Ontario, OPH reported.