Western Equine Encephalitis MapWe would like to acknowledge and thank the Centers for Disease Control for allowing
the use of the following information and links concerning mosquito-borne illness.

Challenges:

  • No licensed vaccine for human use
  • No effective therapeutic drug
  • Unknown overwintering cycle
  • Control measures expensive
  • Limited financial support of surveillance and prevention

Trends:

  • Epidemic disease that is difficult to predict
  • Risk exposure increases as population expands into endemic areas

Surveillance:

  • National Notifiable Diseases Surveillance System

Risk Groups:

  • Residents of endemic areas and visitors
  • Persons with outdoor work and recreational activities

Transmission:

  • Mosquito Borne

Costs:

  • Total case costs range from $21,000 for transiently infected individuals to $3 million for severely infected individuals
  • Insecticide applications can cost as much as $1.4 million depending on the size of area treated

Sequelae:

  • Mild to severe neurologic deficits in survivors.

Incidence:

  • 639 confirmed cases in the U.S. since 1964.

Etiologic Agent:

  • Western equine encephalitis virus, member of the family Togaviridae, genus Alphavirus. Closely related to eastern and Venezuelan equine encephalitis viruses

Clinical Features:

  • Symptoms range from mild flu-like illness to frank encephalitis, coma and death.