Western Equine Encephalitis is a virus transmitted through the
bite of an infected mosquito. The transmission cycle is between
wild birds and mosquitoes. A mosquito will bite a bird infected
with Western Equine Encephalitis and become infected. While
looking for another blood meal, an infected mosquito can infect
an uninfected bird, horse, or human. In past outbreaks, this
disease has caused severe illness and death in horses.
What are the signs and symptoms of Western Equine Encephalitis?
No Symptoms: Most of those infected with
Western Equine Encephalitis will have no symptoms or signs and
never feel sick
Mild Symptoms: Most of those who do have
symptoms or signs will have a fever and headaches
Severe Symptoms: Few of those infected have
the severe symptoms, the old and the young. These include high
fever, stiff neck, vomiting, lethargy, disorientation,
seizures, and possible death
Is Western Equine Encephalitis seasonal?
Yes, it is most likely to occur in late spring to early summer.
Is Western Equine Encephalitis in San Mateo County?
Western Equine Encephalitis is sometimes detected
in mosquito
pools and sentinel
chickens in Southern California but has not been found
in San Mateo County recently.
