Sudbury High Risk Level for West Nile Virus 9/5/2025
FOR IMMEDIATE RELEASE
September 5, 2025 High Risk Level – West Nile Virus (WNV)
The Massachusetts Department of Public Health (MDPH) has announced that Sudbury’s risk classification for West Nile Virus has been raised to high. While no human cases have been reported in Sudbury at this time, recent increases in positive mosquito pools in Sudbury and neighboring communities have elevated risk levels across the region. As a result, Sudbury and several surrounding communities have had their risk classification for West Nile Virus raised to high.
West Nile Virus is a disease spread by mosquitoes that can affect both humans and animals. Most people infected with the virus experience no symptoms, but some may develop mild flu-like symptoms or, in rare cases, serious neurological conditions. Prevent mosquito bites by using repellents, wearing protective clothing, and eliminating standing water around your home.
Avoid Mosquito Bites:
• Apply Insect Repellent when you go outdoors. Use a repellent with DEET (N, N-diethyl-m-toluamide), permethrin, picaridin (KBR 3023), IR3535 or oil of lemon eucalyptus [p-methane 3, 8-diol (PMD)] 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. Permethrin products are intended for use on items such as clothing, shoes, bed nets and camping gear and should not be applied to skin.
• Clothing Can Help reduce mosquito bites. Although it may be difficult to do when it’s hot, wearing long-sleeves, long pants and socks when outdoors will help keep mosquitoes away from your skin.
• Be Aware of Peak Mosquito Hours – The hours from dusk to dawn are peak biting times for many mosquitoes. When risk is increased, consider rescheduling outdoor activities that occur during evening or early morning. If you are outdoors at any time and notice mosquitoes around you, take steps to avoid being bitten by moving indoors, covering up and/or wearing repellant.
Mosquito-Proof Your Home
• Drain Standing Water – Many mosquitoes lay their eggs in standing water. Limit the number of places around your home for mosquitoes to breed by either draining or getting rid of items that hold water. Check rain gutters and drains. Empty any unused flowerpots and wading pools, and change water in birdbaths frequently.
• Install or Repair Screens – Keep mosquitos outside by having tightly-fitting screens on all your windows and doors.
While Sudbury continues to collaborate with the Massachusetts Department of Public Health (MDPH) and other partner agencies, we are also working closely with the East Middlesex Mosquito Control Project to expand mosquito surveillance within the community. Last night, the East Middlesex Mosquito Control Project conducted truck-mounted spraying in the southeastern quadrant of town.
Information about mosquito control data and reports of current and historical WNV virus activity in Massachusetts can be found on the MDPH website at mass.gov/info-details/massachusetts-arbovirus-update.