West Nile Virus

Home Treatment

West Nile virus causes an infection that can lead to inflammation of the brain (encephalitis), the spinal cord (myelitis), or the tissues surrounding the brain and the spinal cord (meningitis). If you have a fever and headache that continue for more than 2 or 3 days during West Nile virus season, or if you have any of the more severe symptoms of West Nile encephalitis, call your doctor immediately.

If your doctor determines that you have a mild infection, make sure to drink plenty of fluids and get lots of rest. You may feel well enough to continue your normal activities. Talk to your doctor about whether you need to stay home.

You can take steps to lower your risk of mosquito bites:

• Stay indoors at dawn, at dusk, and in the early evening, when mosquitoes are most active.
• Wear long-sleeved shirts and long pants whenever you are outdoors and are likely to be where mosquitoes are.
• Avoid wearing floral fragrances from perfumes, soaps, hair care products, and lotions. These may attract mosquitoes.
• Spray clothing with an insect repellent containing permethrin or DEET (N,N-diethyl-meta-toluamide), because mosquitoes may bite through thin clothing. DEET can damage plastic items, such as watch crystals or eyeglass frames, and some synthetic fabrics. You also can use natural products such as soybean-based Bite Blocker.
• Apply insect repellent sparingly to exposed skin. An effective repellent will contain 24% DEET. In Canada, insect repellents with DEET concentrations above 30% are not available. Research shows that DEET strengths greater than 50% do not provide much better protection than those with 30% DEET.
• Avoid applying repellent to the hands of children. Repellents may irritate the eyes and mouth.
• Whenever you use an insecticide or insect repellent, be sure to read and follow the directions for use.
• Do not keep open containers of water near your house. Standing water is a breeding place for mosquitoes.

Vitamin B and ultrasonic or ultraviolet (UV) devices such as "bug zappers" are not effective in preventing mosquito bites.

Mosquito protection time of DEET

Concentration of DEET	Protection time (approximate)
30%	6 hours
15%	5 hours
10%	3 hours
5%	2 hours

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Author:	Douglas Dana Maria G. Essig, MS, ELS	Last Updated: December 5, 2008
Medical Review:	Anne C. Poinier, MD - Internal Medicine Caroline S. Rhoads, MD - Internal Medicine W. David Colby IV, MSc, MD, FRCPC - Infectious Disease Christine Hahn, MD - Epidemiology
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