NEWMARKET: York Region Health Services reports that a mosquito pool has tested positive for West Nile virus (WNv). A "pool" defines one batch of mosquitoes caught overnight in one trap and sent for testing.
The mosquitoes were trapped in the Town of East Gwillimbury, close to the intersection of Leslie Street and the Mount Albert Sideroad. The positive mosquitoes are the first this year in York Region. Surveillance for the virus will be increased in this area.
There were 6 positive mosquito pools reported last year in York Region. To date in 2004, three birds have tested positive for WNv, one found in Aurora, one in East Gwillimbury and one in Whitchurch-Stouffville. There have been no human cases reported this summer.
Trapping mosquitoes is part of the 2004 York Region WNv control plan. Traps are set up at various locations throughout the Region, with mosquitoes sent for testing. The positive mosquitoes were trapped July 20th.
Larviciding of catch basins in the area is ongoing, as part of the York Region WNv control plan. In addition, larvicide has been placed in area ditches and temporary or permanent standing water pools including storm water management ponds if evidence of mosquito breeding was found. Larviciding interferes with the mosquito life-cycle, preventing the mosquito larva from reaching maturity.
West Nile virus is spread by mosquitoes that become infected by feeding upon West Nile virus-infected birds. The infected mosquito, when taking a blood meal from a human, passes on the virus. The disease is also passed on from the infected female mosquito to eggs and subsequent larvae that are produced.
The chances of being bitten by an infected mosquito are rare. In fact, for the very few who are bitten by an infected mosquito most do not even know it, with approximately four out of five people infected by West Nile virus not showing any symptoms or signs of illness at all.
The symptoms for West Nile virus illness consist of fever, muscle weakness, stiff neck, confusion, severe headache, and a sudden sensitivity to light. For a very rare few, the virus causes serious neurological illness including encephalitis (inflammation of the brain).
Prevention and protection are the best ways to protect yourself and your family from West Nile virus. There are simple and common sense precautions that should be taken:
• Minimize outdoor activities where and when mosquitoes are most active such as dusk, night and dawn
• Wear protective clothing such as long sleeved shirts, full-length trousers, socks, light coloured clothing and tuck pant legs into socks when possible.
• Consider using an insect repellent containing 10% DEET or less, as directed
• Make sure screens on your home are tight-fitting and in good repair
• Mosquitoes breed in still water. Eliminate stagnant water around your property which may gather in pool covers, flower pots, children's pools, old tires and birdbaths
To report a dead crow or blue jay and for more information on West Nile virus or any health-related concern, contact York Region Health Services Health Connection at 1-800-361-5653 or visit www.region.york.on.ca