Press Release  State health officials raise risk from EEE to high in two communities

Boston — The Massachusetts Department of Public Health (DPH) today announced that Eastern equine encephalitis (EEE) has been detected in additional mosquito samples collected in Abington, Middleborough, Wareham, and Whitman. These findings raise the EEE risk level to high in Carver and Middleborough and to moderate in Bridgewater, Lakeville, and Rochester.

This is in addition to the 12 communities already at moderate risk for EEE: Amesbury, Groveland, Halifax, Haverhill, Kingston, Merrimac, Newburyport, Plymouth, Plympton, Salisbury, Wareham, and West Newbury.

The first EEE-positive mosquitoes in Massachusetts in 2024 were announced on July 3 from Carver. There have also been EEE-infected mosquitoes identified in Halifax and Kingston in Plymouth County, Barnstable in Barnstable County, and Amesbury and Haverhill in Essex County.

“Summer is a time for people to be outside and enjoy themselves. We want people to have fun and keep themselves safe by being informed about where EEE is being found in mosquitoes,” said Public Health Commissioner Robbie Goldstein, MD, PhD. “Everyone should take the recommended steps to prevent mosquito bites. We recommend that people in high-risk areas use mosquito repellents any time they are outside and consider rescheduling outdoor activities that occur during the evening or early morning.”

EEE is a rare but serious and potentially fatal disease that can affect people of all ages. EEE is generally spread to humans through the bite of an infected mosquito. There were 12 human cases of EEE in Massachusetts in 2019 with six deaths, and five human cases with one death in 2020. There were no human cases of EEE in Massachusetts in 2021, 2022 or 2023.

“The mosquitoes that are most likely to spread EEE are most active between the hours of dusk and dawn,” said State Epidemiologist Dr. Catherine M. Brown. “They are also more active during hot and humid weather. We all want to enjoy this last month of summer but also want people to take steps to be safe from mosquitoes.”

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

Avoid Mosquito Bites

Apply Insect Repellent when Outdoors. Use a repellent with an EPA-registered ingredient, such as DEET (N,N-diethyl-m-toluamide), permethrin, picaridin (KBR 3023), or oil of lemon eucalyptus (p-menthane-3,8-diol (PMD) or IR3535) according to the instructions on the product label. DEET products should not be used on infants under two months of age and should be used in concentrations of 30 percent or less on older children. Oil of lemon eucalyptus should not be used on children under three years of age.

Be Aware of Peak Mosquito Hours. The hours from dusk to dawn are peak biting times for many mosquitoes. Consider rescheduling outdoor activities that occur during evening or early morning in areas of high risk.

Clothing Can Help Reduce Mosquito Bites. Wearing long sleeves, long pants and socks when outdoors will help keep mosquitoes away from your skin.

Mosquito-Proof Your Home

Drain Standing Water. Mosquitoes lay their eggs in standing water. Limit the number of places around your home for mosquitoes to breed by draining or discarding items that hold water. Check rain gutters and drains. Empty unused flowerpots and wading pools and change the water in birdbaths frequently.

Install or Repair Screens. Keep mosquitoes outside by having tightly fitting screens on all windows and doors.

Protect Your Animals

Animal owners should reduce potential mosquito breeding sites on their property by eliminating standing water from containers such as buckets, tires, and wading pools – especially after heavy rains. Water troughs provide excellent mosquito breeding habitats and should be flushed out at least once a week during the summer months to reduce mosquitoes near paddock areas. Horse owners should keep horses in indoor stalls at night to reduce their risk of exposure to mosquitoes. Owners should also speak with their veterinarian about mosquito repellents approved for use in animals and vaccinations to prevent West Nile virus (WNV) and EEE. If an animal is suspected of having WNV or EEE, owners are required to report to the Department of Agricultural Resources, Division of Animal Health by calling 617-626-1795, and to the Department of Public Health by calling 617-983-6800.

More information, including all WNV and EEE positive results, can be found on the Arbovirus Surveillance Information web page at Mosquito-borne Diseases | Mass.gov, which is updated daily, or by calling the DPH Division of Epidemiology at 617-983-6800. 

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