The number of human cases of West Nile virus in Massachusetts has more than doubled to seven this season, and public health officials have classified Cambridge, Somerville, Watertown and Newton as particularly at risk for the mosquito-borne disease.
The Department of Health said three men – one in their forties, one in their sixties and one in their 80s – had been exposed to the West Nile virus in Middlesex County. The fourth new case was diagnosed in a woman under the age of 19. DPH said she was exposed in Bristol County.
DPH said the Boston area had most of the state’s West Nile virus activity this year and classified Cambridge, Newton, Somerville and Watertown in the high risk category on Thursday. Concord, Lexington, Lincoln, Sudbury, Waltham, Wayland, Weston, and Winchester were placed in the medium risk category. In Bristol Counties, Dighton, Fall River, and Swansea are also classified in the medium risk category.
In July, Governor Charlie Baker signed a bill giving the State Reclamation and Mosquito Control Board new powers to control mosquito-borne diseases such as EEE and West Nile Virus when DPH detects an increased risk.
With Thursday’s announcement that the number of cases of West Nile virus in humans was up to seven, Massachusetts surpassed the number of cases in 2019. Last year, five human cases were reported, according to the DPH. Officials across Massachusetts said people across Massachusetts should use mosquito repellants with an EPA-registered ingredient, wear long sleeves and pants outdoors to reduce exposed skin, and be aware of mosquito activity in the community.