Press Release  State officials announce plans to spray for mosquitoes in sections of Worcester and Plymouth counties due to EEE

Boston — The Massachusetts Department of Public Health (DPH) and the Massachusetts Department of Agricultural Resources (MDAR) today announced plans to conduct aerial spraying for mosquitoes in areas of Plymouth County, and truck-mounted spraying in parts of Worcester County. As of today, 10 communities in Massachusetts have been raised to high or critical risk for the Eastern Equine Encephalitis (EEE) virus by DPH. 

The State Reclamation and Mosquito Control Board (SRMCB), with the assistance of MDAR, will conduct and monitor aerial spraying in parts of Plymouth County and oversee truck-mounted ground spraying in parts of Worcester County.  

The eight communities in the aerial spray zone are Carver, Halifax, Kingston, Middleborough, Plymouth, Plympton, Rochester, and Wareham. 

The five communities in the truck spray zone are Douglas, Dudley, Oxford, Sutton, and Uxbridge. 

The planning and coordination for the upcoming spraying operation are in progress. Details on the exact timing will be provided as soon as possible, but spraying is expected to occur during the week of August 26th. Spraying is scheduled to take place at night, starting shortly after dusk and ending in the early morning. Please be aware that this schedule is weather-dependent and may change on short notice. Residents will be able to visit DPH’s website for further information as it is made available. 

EEE is a rare but serious and potentially fatal disease that can affect people of all ages. On August 16, DPH announced this year’s first human case of EEE virus infection, a male in his 80s who was exposed to EEE in Worcester County. During the last EEE outbreak in Massachusetts in 2019-2020, there were 17 human cases and seven deaths. 

“We have not seen an outbreak of EEE for four years in Massachusetts,” said DPH Commissioner Robbie Goldstein. MD, PhD. “This year’s outbreak and activity raise the risk for communities in parts of the state. We need to use all our available tools to reduce risk and protect our communities. We are asking everyone to do their part.” 

“Due to the increased EEE risk and the first human case of the season, the state is taking decisive action to protect public health,” said MDAR Commissioner Ashley Randle. “Aerial spraying will target mosquitoes carrying the EEE virus. While these measures are crucial for reducing transmission risk, it's vital for everyone to stay vigilant and follow personal protection guidelines to safeguard our community.” 

The pesticide used is Anvil 10+10, an EPA-registered product extensively tested and used in both ground-level and aerial spraying in the U.S. to control mosquitoes. Compounds in this product have proven to be highly effective in killing mosquitoes worldwide for over 20 years.  

Anvil 10+10 is applied using an ultra-low volume (ULV) aerosol that uses very small quantities of the insecticide. It is unlikely a person would be exposed to amounts that would cause adverse health effects. Although special precautions are unnecessary, residents in the affected areas who prefer to avoid or minimize exposure can stay indoors during spraying. People with known sensitivities to chemicals or existing respiratory conditions, such as asthma, are encouraged to stay indoors during spraying to reduce the chances of aggravating those conditions. Consumption of vegetables and fruits grown in the treated area or drinking water that might be taken from surface water bodies near spraying operations is considered safe. 

Fish are less likely to be at the surface feeding and honeybees are likely to be in their hives during evening spraying. Owners of small ornamental fishponds in the aerial spray area of Plymouth County should cover them during the night of spraying. For beekeepers, if bees are congregating outside the hive box(es), consider applying a cover to the hive entrance or over the entire hive box(es) using a loose wet cloth (burlap, sheet, etc.) to prevent bees from exiting and coming into direct contact during the application. It's not necessary to bring animals indoors during spraying, but keeping pets inside will minimize their exposure. 

While these mosquito control sprays are necessary to reduce human risk from EEE, they will not eliminate it. All residents are reminded to continue protecting themselves from mosquito bites by applying insect repellent with an EPA-registered active ingredient whenever they are outdoors. Communities at high and critical risk are advised to schedule outdoor activity to avoid dusk to dawn hours, in order to minimize exposure to the mosquitoes most likely to spread EEE. The DPH recommends the following precautions: 

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-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 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. 

For an FAQ regarding mosquito control and spraying, please visit the DPH website here.  

For questions about spraying, contact the MDAR Crop and Pest Services at mosquitoprogram@mass.gov.                

For the most updated information on EEE risk and disease, contact the DPH Division of Epidemiology at (617) 983-6800 or visit the DPH website Mosquito-borne Diseases | Mass.gov for updated risk levels, mosquito results, maps, and incidence of positive mosquito samples. 

For questions about mosquito control in your city or town, contact your local board of health. 

For general information about mosquito control, contact the State Reclamation and Mosquito Control Board within MDAR at (508) 281-6786 or email mosquitoprogram@mass.gov. 

Download this press release in other languages

The following are Word documents.

Albanian | Arabic | Greek | Haitian Creole | Italian | Polish | Portuguese (Brazil) | Portuguese (Portugal) | Simplified Chinese | Spanish | Traditional Chinese | Vietnamese

###