Ottawa Public Health is asking people in the city to protect themselves against mosquito bites after it recently found West Nile virus in local mosquitoes for the first time this year.

On Tuesday the agency said its trappers and testers had found the virus during their weekly rounds, without specifying where.

It said in a news release people could help avoid mosquito bites by:

Reducing standing water sites around their home (bird baths, toys, flower pot saucers, swimming pool covers, etc.).

Applying a Health Canada-approved mosquito repellent containing DEET or Icaridin to exposed skin and clothing.

Protecting themselves especially between dusk and dawn, periods when mosquitoes are most active, and at any time in shady, wooded areas.

Wearing light-coloured and tightly woven clothing such as long pants, a long-sleeved shirt, shoes and socks to protect exposed skin.

Making sure all windows and doors in their home have screens that are in good condition.

Ensuring all openings to rain barrels are covered with screen mesh at all times.

West Nile virus is transmitted from birds to humans by mosquitos, according to Health Canada, which said 70 to 80 per cent of people who are infected don't have any symptoms.

People who do feel the effects of West Nile virus have symptoms ranging from fever, headaches and rashes to, in very rare cases, paralysis and loss of consciousness, Health Canada said.

Symptoms usually appear two to 15 days after someone gets bitten by an infected mosquito and have a greater chance of being more severe in people who are older than 50 or have weaker immune systems.

No human cases in Ottawa last year

There have been no confirmed or probable human cases of the virus in Ontario as of July 30, according to Ottawa Public Health.

The last time there was a confirmed or probable case of West Nile virus in Ottawa was in 2014, a down year overall for West Nile virus in the capital because of cooler than normal temperatures killing off the virus.

2016: City announces it's found a mosquito with West Nile on Aug. 9.<br><br>2015: Unsure.<br><br>2014: Sept. 4.<br><br>2013: Aug. 1.<br><br>2012: Aug. 7. —@amkfoote

Fiona Smaill, a medical microbiologist at McMaster University in Hamilton, told CBC News in late July it's hard to predict how widespread West Nile virus will be during any given year because there are a number of factors at play.

"I think we'd like to think a dry summer means there would be less mosquitoes around [because that means less standing water for them to breed]," she said.

"But remember, this dry and hot summer came on the tails of a fairly mild winter for us in Ontario so potentially the mosquitoes were able to breed earlier than they might have done otherwise."