Equine Encephalitis

Affecting horses and humans, equine encephalitis is a type of inflammation of the brain. Forms of equine encephalitis include: eastern equine encephalitis, western equine encephalitis, and Venezuelan equine encephalitis. Fewer than 10 human eastern equine encephalitis cases are seen annually in the United States. In South and Central America, epidemics of the Venezuelan form of the disease have killed thousands of people.

 

An Overview of Equine Encephalitis

Equine encephalitis is an inflammation of the brain that affects horses and humans.
 

Eastern Equine Encephalitis

In addition to infecting horses and humans, eastern equine encephalitis also infects birds that live in freshwater swamps of the eastern U.S. seaboard and along the Gulf Coast.
 
In humans, eastern equine encephalitis symptoms are seen 4 to 10 days following transmission and include:
 
  • Sudden fever
  • General flu-like muscle pains
  • Headache of increasing severity
  • Coma and death (in severe cases).
     
About half of all infected patients die from eastern equine encephalitis.
 
Fewer than 10 human eastern equine encephalitis cases are seen annually in the United States.
 

Western Equine Encephalitis

Western equine encephalitis is seen in farming areas in the western and central plains states.
 
Western equine encephalitis symptoms begin 5 to 10 days following infection. Children, particularly those under 12 months of age, are affected more severely by western equine encephalitis than adults and may have permanent neurological damage.
 
Death from western equine encephalitis occurs in about 3 percent of cases.
 
(Equine Encephalitis Continued: Page 2)
Written by/reviewed by: Arthur Schoenstadt, MD
Last reviewed by: Arthur Schoenstadt, MD