Eastern Equine Encephalitis (EEE) is a rare, but serious disease
caused by a virus that is carried by many species of swamp
breeding mosquitoes. EEE virus (EEEV) occurs in the eastern half
of the United States where it causes disease in humans, horses,
and some bird species. Because of its high mortality rate, EEE
is regarded as one of the most serious mosquito-borne diseases
in the United States. The incubation period for Eastern equine
encephalitis virus (EEEV) disease (the time from infected
mosquito bite to onset of illness) ranges from 4 to 10 days.
EEEV infection can result in one of two types of illness,
systemic or encephalitic (involving swelling of the brain,
referred to below as EEE). The type of illness will depend on
the age of the person and other host factors. It is possible
that some people who become infected with EEEV may be
asymptomatic (will not develop any symptoms). Systemic infection
has an abrupt onset and is characterized by chills, fever,
malaise, arthralgia, and myalgia. The illness