About Western Equine Encephalitis

On this page:
Fact Sheet
Transmission
Prevention
Signs and symptoms

Fact Sheet

• Western Equine Encephalitis Fact Sheet
  Answers to frequently asked questions about western equine encephalitis.
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Transmission

• Western equine encephalitis is one of several mosquitoborne diseases that has been seen in Minnesota.

Prevention

• Preventing Mosquitoborne Diseases
  Learn how to minimize your risk to western equine encephalitis and other diseases transmitted by mosquitoes.
  
  
• There is a vaccine available for horses to prevent western equine encephalitis. Please contact your veterinarian for vaccine recommendations.

Signs and symptoms

• Most people infected with western equine encephalitis virus will have either no symptoms or a very mild illness.
  
  
• A small percentage of people, especially infants and elderly people to a lesser extent, may develop encephalitis (inflammation of the brain).
  
  
• Approximately 5-15% of these encephalitis cases are fatal, and about 50% of surviving infants will have permanent brain damage.
  
  
• Most of the severe human cases begin with a sudden onset of fever, headache, stiff neck, vomiting, and lethargy.
  
  
• Within two to four days, the illness may progress into disorientation, irritability, seizures, and coma.
  
  
• There is no treatment for WEE other than supportive care until the acute phase of the illness is over.