Sun Country’s Medical Health Officer, Dr. Lanre Medu wants to notify residents that the risk of West Nile virus infection is increasing. This past week, some of the mosquitoes (Culex tarsalis) that were caught in our surveillance traps were found to be infected with West Nile virus.
“The risk for West Nile Virus has always been there, but it is increasing. It is not yet at threshold,” said Dr. Medu. The West Nile Virus surveillance program does a mosquito count and tests for risk weekly.
The Saskatchewan government has a website posting the West Nile Virus risk levels and surveillance results. The southeast is reporting a moderately high risk for West Nile Virus at this time.
With the increased risk, the Sun Country Health Region has taken action to reduce infection. Dr. Medu stated that the province is recommending that residents follow the “Five Ds” to reduce the chances of getting infected with WNV for the remainder of the summer and early fall. He said that the first recommendation is to use effective insect repellant containing DEET.
Repellents with icaridin and oil of lemon and eucalyptus are also found to be effective. Secondly, homeowners should drain standing pools of water like wading pools, wheelbarrows, containers, rain downspouts and gutters, to help reduce the mosquito population, Dr. Medu noted. Mosquitoes need water to lay eggs and complete their life cycle.
Adult mosquitoes also like tall grasses and weeds, so cutting these areas can reduce their populations.
The Sun Country Health Region also suggests that people cut back on the amount of time they spend outside between dusk and dawn. The mosquitoes that carry West Nile Virus are most active in the early morning and early evening, especially two hours after sunset. Those who have to be outside wear long sleeves and long pants. Mosquitoes may be more attracted to individuals wearing perfumes and colognes. A final recommendation from the health region is to mosquito-proof the home. Doors and windows need to have tight-fitting screens and any holes should be repaired.
Dr. Medu noted that these are all preventative measures because there is no cure for WNV in humans. West Nile disease is caused by a virus. It is transmitted to humans from infected birds through the bite of the Culex tarsalis mosquito. WNV mosquitoes are most active and present in high numbers from early in May to late September and early October. The risk of becoming infected varies each year, depending on weather conditions and the number of infected mosquitoes.
West Nile virus is not transmitted from person-to-person or from animal-to-person through casual contact. “Of particular interest are persons who work outside, especially at dusk and dawn, and those who are camping over the next few weeks. These persons are at higher risk of being bitten by mosquitoes and should pay particular attention to preventing these bites,” said Medu.
He points out that those spending a lot of time outside, particularly now during the harvest season on the farm, are at higher risk of being bitten by mosquitoes.
West Nile virus is a relatively new disease in North America. It is only determined by a blood test. Its long-term effects are not fully understood. The symptoms of West Nile disease are fever, chills, rash, vomiting, diarrhea, headache, body aches, and back and joint pain. About 20 per cent of people who become infected will experience these symptoms, while some will feel no symptoms and may not even realize that they have West Nile virus.
Dr. Medu pointed out that the symptoms are non-specific and people might think that they have the flu or another illness.
