State officials announce 8th EEE horse case in Massachusetts

BOSTON (October 2, 2019)—The Massachusetts Department of Public Health (DPH) today announced that laboratory testing has confirmed the 8th horse infected with Eastern Equine Encephalitis (EEE) virus this year. The horse was stabled in the town of Spencer in Worcester County, a community already considered at high risk for EEE.

No change in risk levels is indicated. There are 35 communities now at critical risk, 53 at high risk, and 121 at moderate risk for the EEE virus in Massachusetts. A map of the state’s current EEE risk levels can be found here.

“We continue to emphasize the need for people to protect themselves from mosquito bites,” said State Epidemiologist Dr. Catherine Brown. “Although mosquito populations are beginning to decline, risk from EEE will continue until the first hard frost.”

There have been 12 human cases of EEE this season in Massachusetts and nine confirmed cases of EEE this year in animals – eight horses and a goat.

State officials continue to remind residents throughout the Commonwealth to take personal precautions to prevent mosquito bites. Residents can learn more about EEE and ways to protect themselves on DPH’s website.

EEE is a rare but serious and potentially fatal disease that can affect people of all ages. EEE occurs sporadically in Massachusetts with the most recent outbreak years occurring from 2004-2006 and 2010-2012. There were 22 human cases of EEE infection during those two outbreak periods with 14 cases occurring among residents of Bristol and Plymouth counties.

EEE virus has been found in 426 mosquito samples this year, many of them from species of mosquitoes capable of spreading the virus to people. An additional 76 mosquitos have tested positive for WNV.

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 (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 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 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 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 DAR, Division of Animal Health by calling 617-626-1795 and to the Department of Public Health (DPH) by calling 617-983-6800.
For the most up-to-date information, Q&As, and downloadable fact sheets about EEE in multiple languages visit the DPH webpage www.mass.gov/eee.