Western equine encephalitis
Mosquito-borne
Epidemiology and Demographics
639 confirmed cases in the U.S. since 1964.
Risk Factors
- Epidemic disease that is difficult to predict
- Residents of endemic areas and visitors
- Persons with outdoor work and recreational activities
- Risk exposure increases as population expands into endemic areas
- Unknown overwintering cycle
Pathophysiology & Etiology
Western equine encephalitis virus, member of the family Togaviridae, genus Alphavirus. Closely related to eastern and Venezuelan equine encephalitis viruses.
History and Symptoms
Symptoms range from mild flu-like illness to frank encephalitis, coma and death.
Other Diagnostic Studies
Risk Stratification and Prognosis
Treatment
- No licensed vaccine for human use
- No effective therapeutic drug
Primary Prevention
- Control measures expensive
- Limited financial support of surveillance and prevention
Cost-Effectiveness of Therapy
- 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
Suggested Reading and Key General References
http://www.cdc.gov/ncidod/dvbid/arbor/weefact.htm