19 August, 2024
The Massachusetts Department of Public Health (DPH) today announced the first human case of Eastern equine encephalitis (EEE) in Massachusetts this year. The person is a male in his 80s who was exposed in Worcester County. As a result, the risk level in the communities of Douglas, Oxford, Sutton, and Webster has been raised to critical, and in Dudley, Northbridge, and Uxbridge the risk is increased to high.
The neighboring communities of Auburn, Charlton, Grafton, Leicester, Mendon, Millbury, Millville, Southbridge, and Upton are now considered at moderate risk.
The season’s first EEE-positive mosquitoes in Massachusetts were announced on July 3rd from Carver. There also have been EEE-infected mosquitoes previously identified in Abington, Halifax, Kingston, Middleborough, Plymouth, Wareham, and Whitman in Plymouth County, Taunton and Westport in Bristol County, Barnstable in Barnstable County, Dedham in Norfolk County, Sudbury in Middlesex County, and Amesbury and Haverhill in Essex County.
“This is the first time we have seen a person infected with EEE in Massachusetts since 2020,” said Public Health Commissioner Robbie Goldstein, MD, PhD. “EEE is a rare but serious disease and a public health concern. We want to remind residents of the need to protect themselves from mosquito bites, especially in areas of the state where we are seeing EEE activity.”
Though rare, EEE is serious and a 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 risk from EEE is high in parts of Plymouth County and critical in parts of Worcester County,” said State Epidemiologist Dr. Catherine M. Brown. “In addition to recommending that people use mosquito repellent with an EPA-registered active ingredient and clothing to reduce exposed skin, we also recommend that evening outdoor events be rescheduled to avoid the hours between dusk and dawn. The mosquitoes most likely to spread EEE are most active during the dusk to dawn hours.”
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.
