What is Eastern Equine Encephalitis

Eastern equine encephalitis (EEE) virus is a member of the genus Alphavirus, family Togaviridae. EEE virus has a single-stranded RNA genome. The virus itself is spherical and has a diameter of 60-65 nanometers. The EEE virus is maintained in an infection cycle between the genome, Culiseta melanura mosquitoes, and bird hosts, often in freshwater swamps. The Culiseta melanura are not considered to be an important transmitter of the EEE virus to people because it feeds almost exclusively on birds. Transmission to humans requires another mosquito species to create a “bridge” between infected birds and uninfected mammals. The virus got its name because 

Origin of The Name

The Eastern Equine Encephalitis virus was first discovered in 1830. It was originally thought to only affect horses, hence the name Eastern EQUINE Encephalitis.

Symptoms and Complications

 The deadly virus attacks your immune system and leads to inflammation in your brain, specifically meningitis and encephalitis. Symptoms include fever, chills, headache, myalgias (muscle pain), arthralgias (joint pain). Neurologic sequelae (central nervous system damage) are seen in up to 50% of the patients, including seizures, paralysis, behavioral changes such as psychosis, and permanent intellectual disability. Several complications have been described, more frequently involving the central nervous system resulting in cognitive, motor, or sensory deficits. Late diagnosis and intervention can result in multiorgan failure, autonomic dysfunction, and ultimately death. Behavioral changes are often described, specifically psychosis.

Treatment, Diagnosis and Prevention

It takes about 4 to 10 days after the original bite of an infected mosquito to develop any symptoms of EEE which makes it difficult to act early. Typically, symptoms start slow like most viruses with an increasing fever. Diagnosis of EEE is based on tests of blood and spinal fluid. These tests typically will look for antibodies the body makes against the viral infection. There is no specific treatment for EEE. Antibiotics are not effective against viruses, and no effective antiviral drugs have been developed. Severe illnesses are treated by supportive therapy which may include hospitalization, respiratory support, and intravenous (IV) fluids. There is no vaccine or preventive drug for EEE. Avoiding mosquito bites is the main source of prevention.