Lexington Warns of West Nile Virus in Mosquitoes

The Town of Lexington announced that the Massachusetts Department of Public Health confirmed on Sept. 17 that mosquito samples testing positive for West Nile virus were found in Lexington, Waltham and Provincetown.

West Nile virus is typically spread to humans through the bite of an infected mosquito. While the virus can infect people of any age, those over 50 face a higher risk of severe illness. The Lexington Health Department said it is working with the state health department and the East Middlesex Mosquito Control Project in response.

Earlier this season, the state also reported West Nile virus-positive mosquito samples in Bedford, Boston, Chatham, Clarksburg, Falmouth, Maynard, Pittsfield, Winthrop, Woburn, Stoneham and Lawrence.

The town is advising residents to take several precautions to avoid mosquito bites. These include wearing long sleeves and pants outdoors, especially during dusk, dawn and nighttime hours when mosquitoes are most active, and using insect repellent containing DEET, permethrin, picaridin, IR3535 or oil of lemon eucalyptus according to label instructions. DEET products should not be used on infants under two months old, and oil of lemon eucalyptus should not be used on children under three.

Residents are also encouraged to remove standing water from their property, repair window and door screens, replace worn weather stripping, and keep swimming pools clean and chlorinated, including removing standing water from pool covers.

Most people infected with West Nile virus show no symptoms, but about 20% may experience fever, headaches, nausea, body aches, vomiting, swollen lymph glands or a rash on the stomach, chest or back.

More information on mosquito-borne illnesses is available on the Department of Public Health's website and its online risk level maps.

Source: Town of Lexington announcement, October 30, 2026.

Checked against the record: before publication this article was automatically compared with the original announcement.