Rest and relaxation may be all that’s on the mind during the carefree days of summer, but as far as mosquitoes are concerned the later days of summer are prime time for transmitting West Nile virus (WNv).

Not only is there plenty of biting time left in the season, this is the time of year when the virus is usually well established in the mosquito and bird populations, making transmission of the virus to humans more of a risk.

West Nile virus is transmitted to humans by mosquitoes that become infected with the virus by feeding on infected birds. Anyone who lives in an area where there are mosquitoes infected with WNv may be at risk of acquiring this illness. Although most people will not become sick if bitten by an infected mosquito, WNv can cause severe illness in some people, and on rare occasions, death.

Those at greatest risk of severe illness are people over the age of 50 and people with chronic diseases or weakened immune systems.

Because there is no way of predicting how widespread WNv will be in a given year, the best way to avoid the virus is to prevent mosquito bites. Mosquitoes are most active from dusk to dawn.

If you are outdoors when there are mosquitoes, wear light-coloured, long-sleeved shirts and long pants and use an insect repellent.

When using any type of insect repellent, use it only when needed and follow the directions, paying careful attention to instructions for use on young children, and the number of times the repellent can be used in a day.

The concentration of DEET should be no greater than 30 per cent for adults, no more than 10 per cent for children and should not be used on children under six months old. Check the label for more detailed information or ask your pharmacist for help.

There are several approved and federally registered DEET-free repellents, but they provide a much shorter time of protection, so read and follow the directions. For more detailed information check the fact sheets by the Pest Management Regulatory Agency, at an address accessible by clicking the link.

Repellent doesn’t have to be applied heavily to be effective – a light coating will do. Use repellent on exposed skin or on top of clothing. Do not use under clothing.

Although personal protection is your best bet in the fight against mosquito bites, by eliminating breeding sites around your home, adult mosquito numbers can be reduced. This can reduce your risk of being bitten.

Keep grass cut and trim shrubs and bushes; change the birdbath water regularly; empty containers like buckets, wheel barrows and pots where water can accumulate; keep eaves troughs and rain gutters clean; and drain plastic covers on lawn chairs and other outdoor equipment weekly.

For more information on ways to protect your family from WNv, call Your Health Connection at 721-7520 (1-877-721-7520) between 8:30 a.m. and 6 p.m., Monday through Friday and speak with a public health nurse, or click the link to the health unit website  .


Dr. Pfaff is one of Simcoe Muskoka’s associate medical officers of health.