Mosquito Borne Illnesses

Updated: 9/4/24

Massachusetts Department of Public Health reports that mosquitoes in several communities have tested positive for Eastern Equine Encephalitis and West Nile virus. 

While transmission is rare, reducing your exposure to mosquito bites is your best prevention.

Eastern Equine Encephalitis (EEE)

Eastern Equine Encephalitis (EEE) is a rare but serious disease caused by a virus. The virus that causes EEE is spread through the bite of an infected mosquito. In Massachusetts, the virus is most often identified in mosquitoes found in and around freshwater, hardwood swamps. 

At present, Massachusetts Department of Public Health (DPH) classifies risk of contracting EEE in Middlesex and Suffolk Counties as remote. Towns in Worcester County have moderate to critical risk. This could change over time.

West Nile virus (WNV)

West Nile virus (WNV) is a mosquito-carried virus that can cause illness ranging from a mild fever to more serious disease like encephalitis or meningitis. Massachusetts DPH classifies risk of contracting WNV as high in Boston, Medford, and Somerville and moderate in Grafton. This could change over time.

Guidance

Tufts University is closely following State and local public health data related to the prevalence and transmission of EEE and WNV. 

Information on how to protect yourself from mosquito-borne infections can be found here. It is recommended that people who are over the age of 50 or immunocompromised avoid outdoor activities during the peak mosquito hours of dusk to dawn.

With respect to guidance for the Tufts community, Tufts University is following Massachusetts Department of Public Health Guidelines, which are available here.