June 17, 2004

York Region starts larviciding program

NEWMARKET: York Region has begun the first phase of the West Nile virus larviciding program. In the first phase, the slow-release pellet-like larvicide will be placed into the catch basins of storm drains within a two kilometre radius around locations where positive human, bird and mosquito cases of West Nile virus were identified in 2003 and, to date, in 2004.
"Larviciding is an important part of our West Nile virus mosquito control program,” said Dr. Helena Jaczek, Commissioner of York Region Health Services and Medical Officer of Health. “The presence of West Nile virus has already been confirmed this season in our community, which, in turn, confirms the need to reduce potential mosquito breeding sites to prevent the spread of the virus."
York Region reported its first (and only, to date) positive bird of this year on May 31st. It was found in the Town of Aurora, close to the intersection of St. John’s Sideroad and Industrial Parkway. Two human cases, 9 birds and 6 mosquito pools tested positive for the virus in York Region in 2003. The Ministry of Health and Long-Term Care attributed 2 deaths in the province last year to West Nile virus illness, with no deaths in York Region.
Larviciding is a low risk and effective measure for the control of West Nile virus. Methoprene is the larvicide that will be used. The slow-release pellet formulation interferes with the mosquito life cycle, preventing the mosquito larva from reaching maturity. It is not sprayed. The products have been approved by both the provincial and federal governments and are considered low risk for humans and the environment when applied in accordance with label instructions
Larvicide will be placed into catch basins in four phases, June through September, and will be applied by Ministry of the Environment licensed applicator Pestalto Environmental Products Inc.  Catch basins which have been treated will be marked with a coloured dot.  
In addition, the larvicide Aquabac may be placed in ditches and temporary or permanent standing water pools including storm water management ponds if evidence of mosquito breeding is found. Signs will be posted along the perimeter of any retention pond or ditch treatment areas.
Approximately 75,000 catch basins will be treated and there are 118 storm water management ponds that are being monitored for mosquito breeding across York Region.
Residents who are concerned about catch basins on private property are requested to place a mesh screen over the catch basin to prevent mosquitoes from entering and exiting the catch basin. A limited number of rear yard catch basins located on private property will be treated with larvicide on a case by case basis.

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.
York Region Health Services reminds residents to report sightings of dead crows and blue jays. Suitable specimens may be collected and submitted to the Canadian Co-operative Wildlife Health Centre in Guelph for testing. All crows and blue jays that are reported will help to map out possible West Nile virus activity in York Region.
Dead crows and blue jays are to be reported to York Region Health Services through the Health Connection information line at 1-800-361-5653.
• Suitable specimens - A suitable specimen must be a crow or blue jay that has died less than 24 hours prior to collection. These birds may be collected by York Region Health Services and sent for testing.
• Unsuitable specimens – Most dead birds will not be suitable for testing, but knowing what species they are and where they died is important information. Do not handle birds with bare hands or dispose of dead birds through the municipal garbage systems. If you choose to handle a dead bird, wear rubber gloves, double bag the bird and contact Health Connection for pick-up.
• Dead bird pick-up service is available - Please contact Health Connection for pickup of dead birds of any species.

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).
See the attached Fact Sheet on York Region’s 2004 West Nile virus Control Plan and simple, common sense precautions that should be taken.
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.
Contact:  Wendy Lewis, York Region Corporate Communications Services
   905-830-4444 Ext. 1238 

Fact Sheet
York Region’s 2004 West Nile virus (WNv) Control Plan
The York Region West Nile virus (WNv) control plan for 2004 includes:
• Mosquito, bird and human surveillance
• WNv control activities, including a larviciding strategy:
- The first larvicide application will be in June and the subsequent applications will be in July, August and September. These applications will target all catch basins in Richmond Hill, Vaughan, Markham, Aurora, Keswick and Holland Landing and other urban areas with catch basins
- In addition, any newly identified positive bird, mosquito and human cases in 2004 will be mapped and larvicide will be applied in the catch basins around those newly detected positives
- Methoprene is the larvicide that will be used. It comes in a slow-release pellet-like formulation and is administered in catch basins when the mosquito is in the larval stage of development. It is not sprayed. It has been approved by both the provincial and federal governments and is considered low risk for humans and the environment when it is applied according to label directions
• The WNv control plan also includes public education regarding common sense and effective measures to prevent exposure to WNv, including brochures, posters, public information sessions and community outreach activities.
Prevention and protection are the best ways to protect yourself and your family from WNv. 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, 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

Media Contact: Wendy Lewis, York Region Corporate Communications Services
   905-830-4444 or 1-877-464-9675, Ext. 1238

The Regional Municipality of York is committed to providing cost-effective, quality services that respond to the needs of our rapidly growing communities.  York Region is comprised of the following nine area municipalities:  Aurora, East Gwillimbury, Georgina, King, Markham, Newmarket, Richmond Hill, Vaughan and Whitchurch-Stouffville.  For more information, visit our Web site at:  www.region.york.on.ca

Contact: Patrick Casey, Senior Media Relations Specialist, York Region

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