4 days ago
Map shows high West Nile virus risk in 10 Massachusetts cities and towns
The risk for West Nile virus is high in 10 cities and towns in Massachusetts, including Boston, public health officials say.
The communities now listed at high risk for the mosquito-borne illness are Acton, Bedford, Billerica, Boston, Brookline, Carlisle, Chelmsford, Dracut, Lowell and Newton, a map from the Massachusetts Department of Public Health shows.
More than 150 samples of mosquitoes in Massachusetts have tested positive for West Nile this summer, but so far there have not been any human cases of the virus in 2025.
There were 19 human cases of West Nile virus confirmed last year in Massachusetts. The virus is spread from the bite of an infected mosquito.
About 80% of people infected will not get sick. Symptoms include fever, headache, nausea, vomiting, and skin rashes. Health officials say severe symptoms like brain inflammation or meningitis happen in fewer than 1% of reported West Nile cases.
People over 50 years old are more likely to develop severe illness. There have been eight West Nile deaths reported in the state between 2014 and 2023.
Eastern equine encephalitis, known more commonly as EEE, has also been found in Massachusetts mosquito samples this summer. EEE is very rare but not treatable, and about 30% of people with the disease end up dying.
No towns are at high risk for EEE, but 12 are at moderate risk. They are Bridgewater, Carver, East Bridgewater, Easton, Halifax, Hanson, Lakeville, Middleboro, Plympton, Raynham, Taunton and West Bridgewater.
Health officials say the best way to avoid mosquito bites is using insect repellent when outdoors, staying inside during the peak mosquito hours of dawn and dusk, and wearing long sleeves and pants.
