Eastern Equine Encephalitis
An Overview of the Disease

Kelly Cammiso
Public Health 101
Professor Brown
May 10, 2013

Abstract
In recent years, Eastern Equine Encephalitis has made national headlines in the media. Although it is rare, the disease has devastating effects, especially the encephalitic form of the disease. The purpose of this literature is to provide an overview of Eastern Equine Encephalitis Virus. History, geographical data, epidemiology, etiology, symptoms, diagnosis, treatment, mortality rates and prevention will be discussed respectively.
History and Geographical Data
According the Centers for Disease Control, the first human case of Eastern Equine Encephalitis Virus (EEEV) was discovered in 1938 in Massachusetts. Devastatingly, thirty children died from the disease. Another case was reported by Nathanial Reade, author of “The War on Mosquitoes,” about a girl who lived in Dover, Massachusetts in 1982. Lisa Healy was only 14 when she came down with EEE. It started with flu-like symptoms and then on a Saturday afternoon her parents became increasingly alarmed and took her to the hospital. After a seizure that occurred that night, she went into a coma for two and a half months. Finally, she came out of it but was partially paralyzed. Currently, she needs 24 hour care and is developmentally somewhere between a two and five year old (Reade, 2001) The disease is somewhat rare, but has made a comeback throughout the past ten years. Coinciding epidemics occurred in Massachusetts during 2004- 2006 and in New Hampshire during 2004 and 2007. In the years following, New York reported its first human case of EEEV in 26 years. More recently, in 2012 Massachusetts reported 7 cases and Vermont reported 8 incidents of the disease.

Epidemiology and Etiology
Silverman (2013) reported that, Eastern equine encephalitis virus (EEEV) is transmitted to humans through the bite of an infected mosquito. Eastern Equine Encephalitis Virus (EEEV) is a member of the genus Alphavirus, family Togaviridae. The virus is an Arbovirus. An arbovirus is a type of virus that is transmitted through an arthropod vector. In this case, the vector is the mosquito. A vector can be anything that transmits the virus to humans. The virus particles are spherical and have a diameter of 60-65 nanometers. EEEV is endemic in North America and the Caribbean and is the cause of most human disease cases. In the United States, averages of 6 cases of EEEV are reported every year. Primarily, people who engage in outdoor activities, near infected areas are at a higher risk. Typically, most of the cases appear between the months of May and October and around swamp lands and coastal areas. This is why the mosquito is the only vector for the human form of the disease. Cases are usually reported in Florida, Georgia, Massachusetts and New Jersey. Individuals between the age of 15 and 50 seem to be at the highest risk of becoming infected with EEEV (Silverman, p 195)
Symptoms
EEEV has an incubation period ranging from 4 to 10 days. This means that somewhere in between four and ten days from the initial bite, a person will begin feeling ill. The infection can be either systemic or encephalitic, meaning it affects the body or causes swelling in the brain. Systemic infection has a rapid onset of flu-like symptoms and is manifested by chills, fever, tiredness, aches and pains. It usually lasts around one to two weeks. Age is an important factor on how quickly the symptoms appear, “In infants, the encephalitic form is characterized by abrupt onset; in older children and adults, encephalitis is manifested after a few days of systemic illness. Signs and symptoms for patients who have the disease that has spread to the brain are a high fever ranging from 103°-106°F, headache, irritability, restlessness, drowsiness, anorexia, vomiting, diarrhea, cyanosis, convulsions, and coma (CDC 2013).” Patients who have the encephalitic and survive can experience very severe symptoms that can last for a few years. The CDC pointed out that: many are left with disabling and progressive mental and physical sequelae, which can range from minimal brain dysfunction to severe intellectual impairment, personality disorders, seizures, paralysis, and cranial nerve dysfunction. Many patients with severe sequelae die within a few years (Eastern Equine Encephalitis, 2010).
Diagnosis and Treatment
The diagnosis of EEE is confirmed by lab tests performed in the blood or the cerebral spinal fluid. Unfortunately there is no cure. The treatment consists of helping the patient survive the complications caused by the disease and to minimize the effects of the symptoms (Eastern Equine Encephalitis, 2010).
Mortality
EEEV is considered the most deadly of all the arboviruses. It is estimated that one-third of all people with the disease die from the disease. Much like the rapid onset of symptoms, death can also occur as early as 2 days after a person starts feeling ill. If the person survives the illness, they can be left with severe mental and physical disabilities and will usually die within a few years. The mortality rate is 30 to 70 percent (Silverman et al 195).

Prevention
The Centers for Disease Control has set up many guidelines for prevention of this disease. Since, there is no treatment, prevention is the only cure. Prevention of the disease consists of a few precautions as per the requirements of the CDC: * Always use repellent when outdoors, use insect repellent containing DEET, picaridin, IR3535 or oil of lemon eucalyptus on exposed skin and/or clothing. The repellent/insecticide permethrin can be used on clothing to protect through several washes. * Try to wear clothing protective clothing including long sleeves and pants when necessary. * Have secure, intact screens on windows and doors to keep mosquitoes out. * Mosquitoes can lay eggs even in small amounts of standing water. Get rid of mosquito breeding sites by emptying standing water from flower pots, buckets, barrels, and tires. Change the water in pet dishes and replace the water in bird baths weekly. Drill holes in tire swings so water drains out. Empty children's wading pools and store on their side after use.
(Centers for Disease Control, 2010)

References
Eastern equine encephalitis. (2010, august 16). Retrieved from http://www.cdc.gov/EasternEquineEncephalitis/gen/pre.html
Reade, N. (2001). The War on Mosquitoes. Yankee, 65(4), 90.
Silverman, M. A., Misasi, J., Smole, S., Feldman, H. A., Cohen, A. B., Santagata, S., &... Ahmed, A. A. (2013). Eastern Equine Encephalitis in Children, Massachusetts and New Hampshire, USA, 1970-2010. Emerging Infectious Diseases, 19(2), 194-201. doi:10.3201/eid1902.120039