Each year, more than two million people die from mosquito-borne diseases worldwide, diseases like malaria, yellow fever and dengue fever. In the United States, there aren’t nearly as many people afflicted with mosquito-borne illnesses as there are in places like Africa and South and Central America, but when an outbreak occurs, such as the West Nile Virus outbreak in 1999, people take note. The most recent case of a mosquito-borne illness making headlines was the death of a four-year-old girl in Oswego County, New York due to a virus known as Eastern Equine Encephalitis.
Eastern Equine Encephalitis (EEE) is a mosquito-borne virus that is most common in the Atlantic and Gulf Coast states, transmitted in nature by the mosquito species Culiseta melanura, which is an avian (bird) feeder – it is suspected that human transmission takes place through bridge vectors. EEE is closely related to Western Equine Encephalitis (WEE) and Venezuelan Equine Encephalitis (VEE). EEE in humans is rare, with only five to ten cases reported annually; it takes four to 10 days for symptoms of EEE to develop, although most people infected will show no signs of illness (only four to five percent of those infected will develop the disease). Those at highest risk for EEE infection are those who live or visit woodland habitats, those who work outside or those who take part in outdoor recreational activities; age ranges for developing a severe case are those under 15 or over 50. Cases can occur from late spring through early fall, and most cases reported are in Florida, Georgia, Massachusetts and New Jersey.
In severe cases, EEE can cause inflammation of the brain (encephalitis), leading to brain damage and possibly death; approximately one-third of all people who develop EEE will die. For mild or systemic cases, symptoms of EEE include chills and fever, lasting one to two weeks before full recovery. For more serious or encephalitic cases, headaches, vomiting, fever, drowsiness and diarrhea are followed by disorientation, seizures and coma. The virus is diagnosed through blood tests or spinal fluid tests.
Treatment for EEE is limited, as there have been no anti-viral drugs discovered and antibiotics don’t work; the usual treatment is supportive therapy, including hospitalization and prevention of other infections.
Prevention is the best way to combat EEE and other mosquito-borne diseases: wear insect repellant with DEET, picaridin or IR3535 on exposed skin or clothing; wear long sleeves and pants outside (particularly in wooded areas); and eliminate standing water on your property.