First positive mosquito sample of EEE found in Massachusetts

BOSTON The Massachusetts Department of Public Health (DPH) announced on Aug. 18 this year's first positive sample of eastern equine encephalitis (EEE) virus from mosquitoes in Carver as well as multiple additional findings of West Nile Virus (WNV) that were identified during the past week. WNV was found in crows from Belchertown, Worcester, Hingham, Plymouth and Barnstable and mosquito samples from Boston, Brookline, Needham, Weymouth, Dedham, Brockton, Dartmouth, Worcester and Medford.

"With as much virus as we are finding in our environment, it is likely that we could start to see human cases," said DPH State Epidemiologist Dr. Al DeMaria. "We are asking that everyone remember to take a few simple steps to protect yourself and your family from getting bitten by mosquitoes. The good news is that steps you take to protect yourself from WNV will also protect you from EEE. These include reducing your exposure to mosquitoes, especially by using mosquito repellent."

While there weren't any human cases of EEE during 2007, there were 13 cases with six deaths during the last outbreak cycle from 2004 through 2006. In 2007, there were six human cases of WNV in Massachusetts. Both EEE and WNV are usually spread to humans through the bite of an infected mosquito. WNV can infect people of all ages but people over the age of 50 are at higher risk for severe disease. EEE is a generally more serious disease in all ages and can even cause death.

This is the latest appearance of EEE in mosquitoes in Massachusetts since 2003, when the first positive was on Aug. 18. While the risk of EEE is low, it is still a risk. However, the risk of WNV infection is high.

WNV positive bird and mosquito results from 2008 can be found on the Arbovirus Surveillance Information web page at

People have an important role to play in protecting themselves and their loved ones from illnesses caused by mosquitoes.