Residents are advised to take extra precaution this mosquito season, the state Department of Public Health announced July 17 that West Nile Virus has been detected in mosquitoes collected from Arlington. The virus circulates the environment between mosquitoes and birds and infected 19 humans in Massachusetts in 2024. No human cases have been reported yet for 2025.
Roughly 80 percent of those diagnosed with the flavivirus are asymptomatic, and those who do experience symptoms often deal with headaches, weakness, myalgia or arthralgia. Gastrointestinal symptoms or a rash also are commonly reported, according to the CDC website.
The CDC warns that the virus can cause an acute febrile illness or neurologic disease. The overall fatality rate for those with the neuroinvasive disease is about 10 percent.
Currently, Arlington is experiencing “moderate” levels of West Nile. In a statement issue by the town yesterday, residents were informed that the virus infects those of all ages; however, people above the age of 50 face a higher risk for severe infection.
The state Department of Public Health advises residents to take all precautions to avoid mosquito bites, including wearing proper insect repellent that is made with “DEET” (N, N-diethyl-m-toluamide), permethrin, picaridin (KBR 3023), IR3535 or oil of lemon eucalyptus. The town also encouraged residents to be aware of peak mosquito hours; from dusk to dawn.
Additional details about West Nile in Arlington are here >>
According to the CDC, the virus is transmitted to humans when mosquitos feed on infected birds, and then bite humans. Unlike birds, however, humans are considered “dead end hosts,” meaning people cannot continue to pass the virus to other biting mosquitoes, since human West Nile bloodstream levels aren’t high enough.
While avoiding outdoor activity will help decrease risk of exposure, the town also reminds residents to mosquito-proof their homes. In addition to installing or repairing window screens, Arlington is encouraging residents to drain or get rid of items in the house which hold water, as many monquitoes lay their eggs in standing water. Specifcally, the town urged the community to check their rain gutters and drains, as well as emptying flowerpots or birdbaths.
For information about the virus and reports of current and historical West Nile activity in Massachusetts, see the MDPH website. Direct questions or concerns to the Arlington Health Department at 781-316-3170.
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This news announcement based on information from the town website and CDC was published Friday, July 18, 2025.
