EEE virus detected in mosquitoes in New Bedford

NOTE: There will be targeted ground spraying for mosquitoes in New Bedford early Thursday morning.

The Massachusetts Department of Public Health (DPH) announced today that eastern equine encephalitis (EEE) virus has been detected in mosquitoes in Massachusetts for the first time this year. The presence of EEE was confirmed by the Massachusetts State Public Health Laboratory today in two mosquito samples that were collected July 15 in the communities of Easton and New Bedford in Bristol County. No human or animal cases of EEE have been detected so far this year. There is no elevated risk level or risk level change associated with this finding.

“It has been several years since we have had significant EEE activity in Massachusetts,” said DPH State Epidemiologist Dr. Catherine Brown. “This is a relatively normal time of year for the first evidence of EEE; continued mosquito surveillance over the next several weeks will help us understand how active this season will be.”

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. The last human case of EEE in Massachusetts occurred in 2013. At the end of the 2018 season, EEE infection was confirmed in a turkey and a horse from Worcester County.

“People have an important role to play in protecting themselves and their loved ones from illnesses caused by mosquitoes. Now that we have evidence that both West Nile Virus (WNV) and EEE are present this season, it is very important to take steps to prevent exposure to mosquitoes,” said Dr. Brown. “We are also asking people to remain aware about the level of virus activity in areas where they live, work, and play. People can check our website for the most current information.”

Current activity information can be found at the DPH website which is updated daily: www.mass.gov/dph/mosquito.

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 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.

More information, including all WNV and EEE positive results, can be found on the Arbovirus Surveillance Information web page at www.mass.gov/dph/mosquito or by calling the DPH Division of Epidemiology at 617-983-6800.