Health unit warns of 'notable increase' in West Nile virus in Ottawa

Ottawa Public Health (OPH) is warning residents about a "notable increase" inWest Nile virus in the cityas more mosquito trapping pools are testing positive for the virus than in past years.

Five of the pools trapsplaced around the city to determine the species and density of the mosquito population are currently testing positive for the virus, OPH said.

That's the highest number of concurrently positive resultssince 2017, when seven pools tested positive at once.

A total of 14 testing pools have tested positive for West Nile virus at various times since the 2024 mosquito season began.

2 human cases reported to OPH

Two human cases of West Nile have been reported in Ottawa this year, the health unit said.

A recent release from OPH warns residents to cover up with loose-fitting clothingand recommends mosquito repellents.

OPH says people can also protect themselves byensuring screens on windows and doors are in good condition, and bydraining any standing water around their home at least once a week.

In addition to West Nile, the discovery of eastern equine encephalitis in a local horse is also causing concern.

Thatvirus, also known as EEEV, is normally transmitted between birds and mosquitoes but can occasionally infect horses and, more rarely, humans through mosquito bites.

OPH says mosquitoes with that virus are normally found close to swampy hardwood forests.Only three human cases of EEEVhave been detected in Ontario, most recentlyin 2022.

Although EEEV infections are rare, OPH warns that like West Nile, the virus can cause "a serious neurological disease and even death."

Virus detected elsewhere

TheKingston, Ont., area's health unit saidit's seen that region'sfirst probable case of the West Nile in a local resident, as well as ina crow.

Kingston, Frontenac and Lennox & AddingtonPublic Health said while four out of five people infected with West Nile will experience no symptoms, some may develop a mild flu-like illness with a fever, headache and body aches that could last more than two weeks. Severe cases are more rare.

Last week, Renfrew County and District Health Unit also issued a news release stating the West Nile virus has been detected in mosquitos in Arnprior, Ont.

Hastings Prince Edward Public Health saidit's also found infectedmosquitoes in the Belleville, Ont., area.