Ottawa Public Health (OPH) is asking residents to protect themselves from mosquito bites while outdoors, after the agency found the West Nile virus in local mosquitoes.

West Nile is a mosquito-transmitted virus that can be transferred to humans through a bite from an infected insect. In a small number of cases, the infection can cause serious illness.

There has been no reported, confirmed or probable human cases of the virus in Ottawa in 2018, OPH said in a news release issued Thursday. In Ontario, as of July 21, there have been two reported human cases this year.

Last year, there were 20 confirmed or probable human cases reported in Ottawa, and 147 confirmed or probable human cases in Ontario.

How to protect yourself

If stung, most people will not develop symptoms, but about 20 per cent may experience flu-like symptoms, including fever, headache, muscle aches and possibly a rash, the agency said.

The more serious illnesses, which occur in less than one per cent of infections, invade the central nervous system. People with weakened immune systems and the elderly face a higher risk of developing a severe illness.

Ottawa Public Health is asking residents to protect themselves and their families by applying mosquito repellent containing DEET or icaridin to exposed skin and clothing, and wearing light-coloured, tightly woven, loose-fitting clothing, including long pants, a long-sleeved shirt, shoes and socks, to protect exposed skin.

Residents should also be cautious about leaving objects outside homes that can hold water, which mosquitoes can lay their eggs in, the agency said.