Manitoba Public Health is clarifying changes to its cost-shared mosquito larviciding program.

Director Richard Baydack says resources are being refocused to where they are most needed and most effective, like high risk zones and bigger communities. He explains small communities have a smaller available treatment area and therefore the impact of larviciding is reduced. "Smaller communities just wouldn't have the effectiveness."

He explains the reason for this is that adult mosquitoes have the potential to fly significant distances and, depending on the direction of the wind, can travel several kilometres in one night.

"So your larviciding is going to be affecting the mosquito larvae but outside your treatment area you'll still have untreated areas where mosquitoes are developing and then they can easily fly back into that treated area, so the effect that you actually see on the West Nile risk is pretty limited."

When asked how the province is determining high-risk areas and where larviciding efforts would be most effective, Baydack explained that officials are using a decade worth of mosquito and human surveillance data.

"We have our historic numbers of mosquitoes as well as those that have tested positive for West Nile. We also have looked at human cases geographically, and so we've divided southern Manitoba into High, Moderate and Low risk zones."

He goes on to say that the amount of provincial funding a community receives for larviciding will depend on its size and the risk zone it is in. He notes that the high-risk zone in southern Manitoba is fairly large but points out that a community's size may contribute to some changes in support.

As for the Province's West Nile Surveillance program, Baydack says there are no changes to the existing network of twenty-nine communities in southern Manitoba.

"So we're going to be trapping every week in those twenty-nine communities and continue to test the Culex Tarsalis mosquitoes for the presence of West Nile Virus."

He adds regular reports of the results are issued, typically on Fridays.

Meantime, Baydack points out that there are precautions individuals can also take to reduce their risk of becoming infected with West Nile.

The list includes:
- regularly and routinely using mosquito repellant
- wearing loose-fitting clothes with long sleeves and long pants
- reducing time spent outdoors during peak times (dusk and dawn)
- reducing standing water around your home
- and ensuring all window and door screens to your home are in tact and tight-fitting