Guide EEE in Massachusetts

Information about Eastern Equine Encephalitis (EEE) and mosquito control.

Table of Contents

Learn about EEE

Eastern equine encephalitis (EEE) is a rare but serious disease caused by a virus that can affect people of all ages. EEE is generally spread to humans through the bite of a mosquito infected with the virus. EEE can cause severe illness and possibly lead to death in any age group; however, people under age 15 are at particular risk. EEE does not occur every year, but based on mosquito sampling, a high risk of occurrence of human cases currently exists. Learn more about EEE and how to protect yourself and your family in this fact sheet about EEE.

Hard frost

A hard frost has now occurred in all communities across the state. People are no longer at risk of mosquito-borne illness in Massachusetts in 2019.

2020 Season

Routine mosquito testing is typically reported June-October. The Department of Public Health will conduct early season surveillance activities to assess the risk of WNV and EEE in 2020. 

Contact information

For information on EEE, contact the DPH Division of Epidemiology (617) 983-6800 or visit the DPH website at

For general information on mosquito control, contact the State Reclamation and Mosquito Control Board within MDAR at (617) 626-1723.

For questions regarding your area, contact your local health department.

For questions about aerial spraying, contact MDAR Crop and Pest Services at (617) 626-1700.

2019 Printable fact sheets