Massachusetts health officials say the state’s first West Nile virus-positive mosquito of the year was detected after mosquitoes were tested in a Clarksburg lab. As officials warn that activity can be hard to predict, they urged residents to use insect repelle
Warmer weather arrived with a familiar reminder for people in the Berkshires: mosquitoes are back, and West Nile virus is already showing up in the state’s testing.
Massachusetts health officials said the first West Nile virus-positive mosquito of the year was found after mosquitoes were tested in a Clarksburg lab. The Massachusetts Department of Public Health said researchers identified the virus in a June 16 batch of mosquitoes tested for certain diseases.
Public Health Commissioner Robbie Goldstein, MD, PhD, said the timing is what officials typically see as summer begins. “With warmer weather and summer officially beginning this week, it is the time of year when we typically begin detecting West Nile virus in mosquito populations,” Goldstein said.
West Nile virus is transmitted to humans through the bite of infected mosquitoes. The DPH said that in 2025, nine people contracted the virus. As of June 25, officials said no human or animal had been diagnosed with the virus in Massachusetts.
For those who can be affected, age plays a role in severity. The DPH said anyone is susceptible, but people older than 50 have a higher risk for “severe disease.” Officials also said most infected patients experience no symptoms, while those who do feel sick can develop fever and flu-like symptoms.
State Epidemiologist Dr. Catherine M. Brown said the pattern of transmission can be difficult to forecast. “With West Nile virus, it is difficult to predict the amount of activity we will see,” Brown said. She advised the public to regularly check mosquito-borne diseases webpages on mass.gov.
The guidance from the DPH focused on practical steps residents can take now. Officials urged people to apply insect repellent containing ingredients such as DEET when they are outside. They warned DEET should not be used on infants under two months old and should be used in concentrations of 30 percent or less.
Health officials also pushed families to reduce mosquito breeding near homes. The DPH advised people to mosquito proof their homes by not having standing water nearby or in the home. explaining that mosquitos lay their eggs in still water. Animal owners were told to empty out buckets, tires, or wading pools, particularly when it rains.
For horse owners, officials’ advice was specific: keep horses in indoor stalls at night to reduce exposure to mosquitoes. The DPH also warned the public about Eastern Equine Encephalitis (EEE). Officials said no mosquitos carrying the virus have been detected as of Thursday.
They added that horse owners should use mosquito repellent on horses that is vet approved.
Officials also set out what to do if an animal appears sick. If an animal is suspected of having WNV or EEE, owners are required to report to the Department of Agricultural Resources, Division of Animal Health by calling 617-626-1795, and to the Department of Public Health by calling 617-983-6800.
West Nile virus Massachusetts Berkshires Clarksburg lab mosquitoes DEET mosquito-borne diseases Robbie Goldstein Catherine M. Brown Eastern Equine Encephalitis EEE
West Nile is back?? great…
So they found it in a lab test, not like someone actually got sick, right? Still better to spray everything though because mosquitoes don’t care. I’m already paranoid about my yard now.
Clarksburg lab… isn’t that where they like, grow stuff or whatever? Feels like they’re testing mosquitoes like every year and people just ignore it until it’s too late. Also “no human or animal diagnosed” but they’re still saying older than 50 is higher risk… so should I be hiding indoors now?
They say “hard to predict” which is funny because every summer it’s the same thing, just different headlines. I swear these mosquitoes are getting worse like climate change plus whatever. Do they actually do anything besides say use repellent? Because I did and I still got bitten day one.