We 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.