Dana BowersBy Dana R. Bowers, Pharm.D., clinical assistant professor, infectious diseases pharmacy specialist, WSU College of Pharmacy

West Nile Virus was recently found in five horses in Spokane County causing people to wonder “What precautions can I take against West Nile Virus?”

Because the West Nile Virus is spread through infected mosquitoes, the most effective way to avoid an infection is to prevent mosquito bites.

West Nile Virus has been causing outbreaks since 1999. Reports of the virus have been found in all of the lower 48 states (not Alaska or Hawaii). Outbreaks of the virus are most common during the summer months and into September. The people who are at the highest risk for infection with the virus are people who work outdoors or participate in outdoor activities due to the increased exposure to mosquitoes.

Although there is no vaccine that can prevent its spread, there are some things that individuals can do to reduce their risk of mosquito bites:

Use insect repellants that are approved by the Environmental Protection Agency (EPA). These repellants have approved ingredients (listed below) that will be the most effective in repelling mosquitoes. It is important to follow the instructions as described on the label and:

  • Apply just enough to cover exposed skin and/or clothing; A heavy application does not give more or better protection
  • Reapply as directed; If you are getting mosquito bites, you need to reapply
  • Examples active ingredients that can be found on the label: DEET, picaridin, IR3535, 2-undecanone, oil of lemon eucalyptus and para-menthane-diol products

Wear long sleeves and pants when mosquitoes are most active (from dawn until dusk)

  • Clothing with a tight weave will do a better job at preventing mosquito bites

Keep mosquitoes outside

  • Use window and door screens and air conditioning if possible
  • Repair any doors or screens as necessary

Reduce the number of mosquitoes near your home

  • Remove sources of standing water from your home such as planters, gutters, buckets, pool covers, pet water dishes and birdbaths where mosquitoes like to lay their eggs

Most people (up to 80%) who are infected with West Nile Virus exhibit no symptoms. A small number of people who are infected (1 out of 5) will develop some symptoms such as headache, body aches, joint pain, vomiting, diarrhea or rash. Most patients with these symptoms recover completely, although fatigue and weakness might last for months.

Very few people infected with the virus (<1%) develop severe symptoms such as encephalitis or meningitis that require hospitalization. Serious infection occurs in all ages but is more common in patients over age 60 or with certain diseases such as cancer, diabetes, high blood pressure (hypertension), kidney disease and people who have received an organ transplant or are immunocompromised.

Once a person becomes infected with West Nile Virus, there is no specific medication that can be used to cure it. All of the current treatment options focus on treating the symptoms such as headache and fever. Therefore, prevention is the best medicine!

For more information, visit the Centers for Disease Control and Prevention.