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Regardless of the West Nile virus (WNV) risk level for your health region, remember there is no such thing as "risk-free". If you can be bitten by a mosquito, you can contract West Nile or other mosquito-borne viruses. The main species that carries WNV in Saskatchewan is Culex tarsalis.

Take precautions when you are out in areas where mosquitoes are present. Protect yourself by covering up and wearing repellents or reducing the amount of time spent outdoors. Mosquitoes can be active at any time but are most active in the evening and throughout the night.

See Frequently Asked Questions for information on symptoms of West Nile Virus infection, when to seek medical attention, treatment and personal precautions against mosquitoes.

This Week's West Nile Virus Risk by ecological risk area* - September 18, 2014

Overall Summary


  • Numbers of culex tarsalis, the mosquito that carries West Nile virus are very low.


  • The potential for West Nile virus transmission has been substantially reduced and the risk will remain low for the rest of the season.


  • Other mosquitoes may still bite on warmer afternoons and toward dusk when the temperatures are above 10° C.


  • Several hard frosts and cooler weather are required to eliminate mosquito populations.

WNV Risk


The mosquito species that carries WNV has not been detected. This does not mean risk is zero.

(yellow) The mosquito species that carries WNV has been detected in small numbers. There is a low probability of being bitten by an infected mosquito.
(orange) WNV mosquitoes have been detected in numbers where there is a moderate probability of being bitten by an infected mosquito.
(red) High numbers of WNV positive mosquitoes have been identified and are widespread. There is an increasing and high probability of being bitten by an infected mosquito.
West Nile Virus Risk Map 

* Ecological Risk Areas:

Mixed-Grass Prairie
(Sun Country,
Regina Qu'Appelle,
Five Hills, Cypress, Heartland
Health Regions)

Moist Mixed-Grass Prairie 
(Sunrise, Saskatoon,
Prairie North
Health Regions)

Boreal Transition
(Prince Albert
Parkland, Kelsey Trail
Health Regions)

Boreal Forest
(Athabasca, Mamawetan Churchill
River, Keewatin Yatthé
Health Regions) 

For a complete description of the criteria used for determining weekly risk, definitions of accumulated degree days, mosquito pools and other WNV risk indicators, 2014 seasonal surveillance results, and general information on WNV prevention see the links below.

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