State public health officials announce season’s second EEE positive mosquito sample

BOSTON (July 6, 2020) – The Massachusetts Department of Public Health (DPH) today announced that eastern equine encephalitis (EEE) virus has been detected in mosquitoes in Massachusetts for the second time this year. The presence of EEE was confirmed today by the Massachusetts State Public Health Laboratory in a mosquito sample collected on July 5 in the community of Wendell in Franklin County. Today’s finding increases the risk level of EEE to moderate in the communities of Wendell and New Salem. On Friday, the state’s first detection of EEE in mosquitoes was also found in Franklin County, which increased the EEE risk level to moderate in the communities of Orange and Athol. No human or animal case of EEE has been detected so far this year.

“We are seeing EEE activity in mosquitoes very early in the season,’’ said Public Health Commissioner Monica Bharel, MD, MPH. “We will continue to conduct additional surveillance, including trapping and testing mosquitoes in the region over the next several weeks to better inform our guidance to local communities.”

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. There were also nine cases in domestic animals.

“This second early finding reinforces our concern about EEE activity this season,” said State Epidemiologist, Dr. Catherine Brown. “We urge all Massachusetts residents to be aware of the risks associated with mosquito bites and to take precautions against being bitten.”

Information about current mosquito activity is updated daily and can be found here.

Avoid Mosquito Bites

Apply Insect Repellent when Outdoors. Use a repellent with an EPA-registered ingredient (DEET (N, N-diethyl-m-toluamide), permethrin, picaridin (KBR 3023), oil of lemon eucalyptus [p-methane 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% 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 either draining or discarding items that hold water. Check rain gutters and drains. Empty any 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 of your 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 (DAR), Division of Animal Health by calling 617-626-1795 and to the Department of Public Health (DPH) by calling 617-983-6800.