English: This 1975 transmission electron micrograph (TEM) revealed the presence of a number of Eastern Equine Encephalitis (EEE) virus virions that happened to be in a specimen of central nervous system tissue. EEE is a zoonotic arbovirus, which means that it’s spead to human beings through the bite of an infected mosquito. 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 the high mortality rate, EEE is regarded as one of the most serious mosquito-borne diseases in the United States. EEE is a Togaviridae virus family member, and the genus Alphavirus.

HUMAN CLINICAL FEATURES: What type of illness can occur?

• Many persons infected with EEEV have no apparent illness. In those persons who do develop illness, symptoms range from mild flu-like illness to EEE (inflammation of the brain), coma and death.
• The mortality rate from EEE is approximately one-third, making it one of the most deadly mosquito-borne diseases in the United States.
• There is no specific treatment for EEE; optimal medical care includes hospitalization and supportive care (for example, expert nursing care, respiratory support, prevention of secondary bacterial infections, and physical therapy, depending on the situation).
• Approximately half of those persons who survive EEE will have mild to severe permanent neurologic damage.