Western Equine Encephalitis

(WEE)

Definition

Western equine encephalitis (WEE) is a virus spread by a bite from an infected mosquito. While WEE is rare, an infected person can become seriously ill and even die from the virus.

Causes

WEE is caused by being bitten by a mosquito that is infected with the virus.

Risk Factors

Factors that may increase your chance of WEE include:
  • Living in or visiting the plains regions of western and central United States
  • Doing activities outdoors and not using insect repellent

Symptoms

Most people with WEE do not have any symptoms.If symptoms do occur, they appear within 5-10 days after infection and include:
  • Headache
  • Fever
  • Neck stiffness
  • Chills
  • Fatigue
  • Joint and muscle pain
  • Vomiting
WEE can lead to more serious, life-threatening symptoms like inflammation of the brain (encephalitis), seizures, and coma . These serious symptoms are more common in infants and older adults.
Encephalitis
Nucleus factsheet image
Copyright © Nucleus Medical Media, Inc.

Diagnosis

In addition to taking your medical history and doing a physical exam, your doctor will ask you:
  • What kind of symptoms you are experiencing
  • Where you have been living or traveling
  • Whether you have been exposed to mosquitoes
Your doctor may need to test your bodily fluids. This can be done with:Imaging tests to evaluate the brain can be done with:

Treatment

Because the infection is viral, there is no specific treatment for WEE. Treatment will focus on managing your symptoms and related complications through:
  • IV fluids
  • Antiseizure medications
  • Medications to decrease brain swelling
  • Breathing support— mechanical ventilation

Prevention

There is no vaccine for humans. There is a vaccine for horses. Prevention of WEE focuses on controlling mosquitoes and avoiding mosquito bites. Steps you can take to avoid mosquito bites include:
  • Stay inside between dusk and dark, when mosquitoes are most active.
  • Wear long pants and long-sleeved shirts when outside.
  • Use an insect repellent with DEET.
  • Repair screens to prevent mosquitoes from entering the house.
  • Use proper mosquito netting at night. Look for netting treated with insecticide.
  • Remove standing water (such as birdbaths, clogged gutters) to prevent mosquito breeding.

Advertisement

RESOURCES

Centers for Disease Control and Prevention
http://www.cdc.gov

National Institute of Allergy and Infectious Diseases
http://www.niaid.nih.gov

CANADIAN RESOURCES

Health Canada
http://www.hc-sc.gc.ca

Healthy Alberta
http://www.healthyalberta.com

References

Fact sheet: Western equine encephalitis. Centers for Disease Control and Prevention website. Available at: http://www.cdc.gov/ncidod/dvbid/arbor/weefact.htm. Updated November 7, 2005. Accessed January 4, 2013.

Meningitis and encephalitis fact sheet. National Institutes of Neurological Disorders and Stroke website. Available at: http://www.ninds.nih.gov/disorders/encephalitis%5Fmeningitis/detail%5Fencephalitis%5Fmeningitis.htm. Updated February 16, 2011. Accessed January 4, 2013.

Reimann CA, Hayes EB, et al. Epidemiology of neuroinvasive arboviral disease in the United States, 1999-2007. Am J Trop Med Hyg. 2008;79(6):974-979.

Western equine encephalitis fact sheet. Minnesota Department of Public Health website. Available at: http://www.health.state.mn.us/divs/idepc/diseases/weencephalitis/wee.html. Accessed January 4, 2013.

10/1/2013 DynaMed Systematic Literature Surveillance http://www.ebscohost.com/dynamed: Reimer LJ, Thomsen EK, Tisch DJ, et al. Insecticidal bed nets and filariasis transmission in Papua New Guinea. N Eng J Med. 2013;369(8):745-753.

Revision Information

Did you like this? Share with your family and friends.
Current Research From Top Journals



March 2015

Many medical groups felt that early exposure to certain foods like peanuts increased a child's risk of developing food allergies. However, newer research including this trial suggest that early exposure may actually decrease the risk of developing food allergies.

dot separator
previous editions

Breastfeeding May Decrease the Risk of Childhood Obesity
February 2015

Tonsillectomy May Reduce Number of Sore Throat Days in Children
February 2015

Research Review Finds Little Support for Nearly Half of Medical Talk Show Recommendations
January 2015

dashed separator

Advertisement

Our Free Newsletter
click here to see all of our uplifting newsletters »

 

Advertisement

Advertisement

DiggDeliciousNewsvineRedditStumbleTechnoratiFacebook