The Andover Health Division was notified today by the Massachusetts Department of Public Health
(MDPH) that a mosquito sample collected in Andover has tested positive for West Nile Virus (WNV). The sample was collected on Monday, September 18, 2023, by personnel from the Northeast Massachusetts Mosquito Control and Wetlands Management District, and was tested at the state lab in Jamaica Plains. Andover joins other communities in the region with mosquito samples that have tested positive, and the Commonwealth has raised the WNV Risk Level from Low to Moderate.
The virus was isolated from the Culex pipiens mosquito, which primarily feeds on birds; there has been no isolation of WNV in mosquitos that would feed on mammals. Due to the lower evening temperatures in the fall, mosquito spraying is not an effective treatment and will not be conducted at this time; crews from the mosquito district have been in Andover today treating appropriate water bodies with larvicide to prevent new broods of mosquitos.
West Nile virus (WNV) is a mosquito-carried virus that can cause illness ranging from a mild fever to more serious disease like encephalitis or meningitis. It was first identified in the United States in 1999. WNV is most commonly associated with urban environments, and mosquitos of concern tend to breed in artificial containers such as untreated pools, abandoned tires, and buckets.
Residents are encouraged to take the following precautionary steps to protect themselves from mosquitos:
• When outdoors during high mosquito activity (usually dusk to dawn), wear long pants and long sleeved shirts.
• Use a repellent with DEET in accordance with the instructions on its label.
• Eliminate standing water from your property.
For more information about mosquitos, visit the MDPH website at https://www.mass.gov/info-details/mosquitoes-in-massachusetts.