EASTERN EQUINE ENCEPHALITIS IS A RARE MOSQUITO-BORNE VIRAL DISEASE THAT CAN ONLY BE TRANSMITTED TO PEOPLE BY THE BITE OF AN INFECTED MOSQUITO. EASTERN EQUINE ENCEPHALITIS IS REGARDED AS ONE OF THE MOST DEADLY MOSQUITO-BORNE DISEASES IN THE UNITED STATES. SYMPTOMS INCLUDE HIGH FEVER, STIFF NECK, HEADACHE, AND LACK OF ENERGY.
Eastern Equine Encephalitis (EEE) reported in 2011
A human case of EEE was reported by the Massachusetts Department of Public Health on Sept. 2. The person was an elderly man from Bristol County who was hospitalized on Aug. 29 and passed away on Sept. 5, according to the Boston Globe.
What is the current risk?
As of October 25, 2011, eastern equine encephalitis had been detected in mosquitoes in Berkley, Bridgewater, Brockton, Carver, Dighton, Easton, Freetown, Halifax, Hanover, Hanson, Holbrook, Hopkinton, Kingston, Lakeville, Medway, Middleborough, New Bedford, Norton, Plympton, Raynham, Rehoboth, Rockland, Sharon, Sherborn, Shrewsbury, Sudbury, Westborough, West Bridgewater, and Weymouth, as well as a horse in Belchertown, according to the Massachusetts Department of Public Health.
How has EEE affected Massachusetts historically?
Massachusetts has the second largest number of reported human cases of eastern equine encephalitis in the country. Between 1964 and 2010, 270 people in the U.S. were infected with the EEE virus. Of these people, 14% lived in Massachusetts.
Outbreak: 2004-2006
Outbreaks of eastern equine encephalitis occur in Massachusetts about once every 10 to 20 years. An outbreak may last two to three years. The most recent outbreak occurred from 2004 to 2006. During this period, there were 13 reported cases and six deaths. At the time, infected mosquitoes were detected in Plymouth, Bristol, Middlesex, Worcester, Norfolk, and Essex counties.
Between 2007 and 2010, one person was infected with EEE in Massachusetts in 2008 and two people in 2010. To learn more about the risk of eastern equine encephalitis in Cambridge and other Massachusetts communities, see the risk map from the Massachusettes Department of Public Health.
What to look for
The EEE virus is carried by birds that live in natural wetlands. It is usually found only in types of birds and mosquitoes that do not bite people. However, when the virus infects large numbers of birds, the virus may infect other species of mosquitoes that do bite horses and people.
To protect yourself from eastern equine encephalitis and other mosquito-borne diseases, see the health department's prevention tips.
For more information, visit the Massachusetts Department of Public Health arbovirus website and the CDC’s EEE fact sheet.
Last updated on October 25, 2011
