Friday, July 30, 2015 – The Massachusetts Department of Public Health (DPH) today announced that they have raised the West Nile Virus (WNV) risk level to “moderate” in Boston, Brookline, Cambridge, Chelsea, Everett, Malden, Medford, Melrose, Newton, Revere, Somerville, and Watertown. This change is due to multiple WNV-positive mosquitos being found in a relatively small geographic area of the Commonwealth that has historically had significant WNV activity. These findings, combined with the current weather patterns (warm/hot and relatively dry) indicate that human risk from WNV has increased. Although not all of the communities identified have had mosquito positives yet, historic evidence shows that WNV activity tends to follow similar patterns throughout all these communities.
No human cases of WNV or Eastern Equine Encephalitis (EEE) have been detected so far this year.
“These findings serve as an important reminder of the need for personal protection from the threat of mosquito-borne illness,” said DPH State Public Health Veterinarian Dr. Catherine Brown. “Protection includes using a mosquito repellent with an EPA-approved ingredient according to the directions on the label, using clothing to reduce exposed skin when weather permits, draining standing water to prevent mosquito breeding and repairing window screens to keep mosquitoes out of your home.”
WNV is usually transmitted to humans through the bite of an infected mosquito. In 2014, there were six human cases of WNV infection identified in Massachusetts. While WNV can infect people of all ages, people over the age of 50 are at higher risk for severe disease. Most people infected with WNV will have no symptoms. When present, WNV symptoms tend to include fever and flu-like illness. In rare cases, more severe illness can occur.
People have an important role to play in protecting themselves and their loved ones from illnesses caused by mosquitoes.
More information, including all WNV and EEE positive results, can be found on the Arbovirus Surveillance Information web page at www.mass.gov/dph/mosquito or by calling the DPH Epidemiology Program at 617-983-6800.