Southeast Saskatchewan residents are being urged to take precautions against the West Nile virus (WNV), now that the high-risk season for the disease has started.
Sun Country Health Region (SCHR) medical health officer Dr. Shauna Hudson said the health region has started to detect some of the Culex tarsalis mosquitoes that carry the virus.
The health region has three mosquito traps in Estevan and several more in Weyburn.
“The traps in Estevan are ones where the earliest indication of Culex tarsalis mosquitoes usually occurs in the province, and they're also the mosquito traps that we look to first to see whether those mosquitoes are getting infected with West Nile,” said Hudson.
Hudson noted that the Culex mosquitoes still account for a fraction of the mosquito population. In one trap with 1,300 mosquitoes, only six were of the Culex variety.
None of the mosquito traps in Estevan, or elsewhere in the province, have had WNV-positive Culex mosquitoes.
Thirty-five Culex mosquito pools have been tested.
“The mosquitoes that are out there right now in droves are nuisance mosquitoes that really bug us when they bite,” said Hudson.
The Saskatchewan Ministry of Health's WNV risk map says the risk for the disease is low in Sun Country and the other health regions in southern Saskatchewan.
“It's been a cooler spring, and so that certainly delays the reproduction of Culex mosquitoes,” said Hudson. “They like hot weather. It's really important to them.”
The Culex insects mostly bite at dusk and dawn, Hudson said. They're low-flying pests that bite around the ankles, and sometimes people won't notice that they have been bitten.
Hudson said it's difficult to say whether there will be a significant number of WNV cases in the health region this year. The most recent year to boast a large number of cases was 2007.
“We certainly plan every year to be prepared for that, but until we start to see all the things come together, it's very difficult to predict whether or not it will be a year with lots of … the West Nile-carrying mosquitoes,” said Hudson.
Hudson said there needs to be a lot of stagnant water and warm temperatures for the mosquitoes to breed effectively.
Conditions also need to be right for mosquitoes to spread the disease to people over the coming weeks, Hudson said.
Hudson said that if people take some simple steps, they can diminish mosquito habitats, and reduce the risk of contracting the disease when more Culex tarsalis mosquitoes are present.
Those steps include:
*Wear a good insect repellant with DEET, and apply it according to directions on the label.
*Drain standing water. Mosquitoes require water to complete their life cycle. Eliminate or reduce all sources of standing water where mosquitoes can lay eggs, like wading pools, wheelbarrows, containers, rain downspouts and gutters, pet dishes and birdbaths. People can also cut long grass and weeds, which is an ideal habitat for adult mosquitoes.
*Avoid going outdoors at dusk and dawn. The mosquitoes that carry West Nile are most active at those times, and also in the early evening. They are especially active for two hours after sunset.
*Dress appropriately. Wear long sleeves and long pants that are light-weight and lightly coloured to minimize the potential for heat-induced illnesses. Mosquitoes may be more attracted to individuals wearing perfumes and colognes.
*Mosquito-proof your home by making sure that doors and windows have tight fitting screens. Screens that have tears or holes should be replaced.
“It's not too soon to start (taking precautions),” said Hudson. “Even though these mosquitoes (Culex tarsalis) aren't currently the ones out there, the things that you need to do are things that will prevent you from being bit by all these nuisance mosquitoes.”
Hudson encourages people to check the websites for the Sun Country Health Region and the Ministry of Health to see updates on the West Nile Virus, and to check the WNV risk map.
Most people who become infected with WNV experience no immediate symptoms or have a very mild illness, with a fever, headaches and body aches. A small number of people develop the more serious WNV neuroinvasive disease, which includes encephalitis – an inflammation of the brain.
The elderly and people with certain medical conditions are at higher risk of developing the severe form of WNV infection.