What is West Nile Virus and how can I keep myself safe from it?



West Nile Virus was first detected in North America in 1999 and was detected in Utah in 2003. West Nile Virus is transmitted by female mosquitoes while taking a blood meal required to lay eggs. Horses, humans and some birds (particularly crows, ravens and jays) are most sensitive to developing West Nile Virus symptoms when compared to other mammals.
Approximately 80 percent of people infected with West Nile Virus never show symptoms. Most people’s immune systems are healthy enough to fight infection. Up to 20 percent of those bitten will develop West Nile Fever and display symptoms similar to the flu. Symptoms last a few days and are treated with fluids and rest. About one in 150 people infected will become seriously ill and require hospitalization. People over 50 or those with compromised immune systems are at higher risk to develop more serious complications from West Nile Virus.
Consider these tips to protect yourself.
  • Wear appropriate clothing. Long-sleeved shirts and pants make it more difficult for mosquitoes to pierce your skin and transmit disease while feeding.

  • Stay indoors during peak flight activity. Mosquitoes that transmit West Nile Virus are most actively feeding from dusk through dawn.

  • Protect yourself with repellent. DEETis an effective mosquito repellent available in several concentrations. Products containing DEET have a relatively low risk to humans and the environment. DEET can be applied to the skin, but should not be applied directly to the face. Children should use DEET sparingly because of eye and mucous irritations. Picaridinis an alternative for people with sensitivities to DEET-based products. It is effective, almost odorless and can be applied directly to the skin. BioUD is sold commercially as Bite Blocker® and is derived from plants. Bite Blocker can be applied to the skin and has no child restrictions. Unlike DEET, BioUD will not melt plastic and is not flammable. Permethrinis a highly effective repellent, and products containing permethrin can be applied to clothing, shoes and camping gear. Oil of eucalyptusis a plant-based repellent and is about as effective as applying low concentrations of DEET.

  • Eliminate standing water. Because mosquito eggs are deposited in standing water, anything you do to reduce breeding sites will decrease the number of adult mosquitoes. This includes improving landscaping to minimize pooling water in ditches and other low spots in the yard.

  • Keep containers clean and dry. Empty and clean watering cans, flower pots or other potential sources of standing water when they are not in use. Drill holes to allow drainage. Garbage cans and recycling bins can hold rain water for days.

  • Maintain pools with fresh water. Frequently change the water around the property, including fish or ornamental ponds, bird baths and pet bowls.

  • Properly chlorinate swimming pools and hot tubs to discourage female mosquitoes from laying eggs.

  • Prevent mosquitoes from entering the home. Keep windows and doors closed, repair torn screens, insulate window fans or air conditioners and close fireplaces when not in use.

Posted on 14 Sep 2006

Erin Hodgson
Extension Entomologist

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