## Overview Eastern equine encephalitis (EEE) and Western equine encephalitis (WEE) are mosquito-borne viral diseases that cause severe neurologic illness. EEE has a mortality rate approaching 90 percent; WEE is less deadly (approximately 30 to 50 percent). Both are core vaccines recommended by the American Association of Equine Practitioners. ## Causes Alphaviruses transmitted by mosquitoes from bird reservoirs. ## Diagnosis Clinical signs of fever and rapidly progressive neurologic disease plus serology or polymerase chain reaction testing. ## Treatment Supportive care only. No specific antiviral therapy exists. Survival is uncommon with EEE. ## Recovery and Prognosis Poor for EEE. Survivors of either disease may have residual neurologic deficits. ## Prevention Annual vaccination and mosquito control.
high fever; depression; circling; head pressing; blindness; seizures; rapid progression to death (especially EEE)
## Overview Eastern equine encephalitis (EEE) and Western equine encephalitis (WEE) are mosquito-borne viral diseases that cause severe neurologic illness. EEE has a mortality rate approaching 90 percent; WEE is less deadly (approximately 30 to 50 percent). Both are core vaccines recommended by the American Association of Equine Practitioners. ## Causes Alphaviruses transmitted by mosquitoes from bird reservoirs. ## Diagnosis Clinical signs of fever and rapidly progressive neurologic disease plus serology or polymerase chain reaction testing. ## Treatment Supportive care only. No specific antiviral therapy exists. Survival is uncommon with EEE. ## Recovery and Prognosis Poor for EEE. Survivors of either disease may have residual neurologic deficits. ## Prevention Annual vaccination and mosquito control.
high fever; depression; circling; head pressing; blindness; seizures; rapid progression to death (especially EEE)