Aerial spraying to combat disease-carrying mosquitoes is expected to start within several days in Southeastern Massachusetts, state health authorities announced Tuesday amid growing concerns about the early arrival of Eastern equine encephalitis.
The decision to launch planes over 11 cities and towns was made after additional samples of human-biting mosquitoes were found infected with Eastern equine in Easton, where virus-carrying insects were also found last week, and in Lakeville. The disease, widely known by the acronym EEE, can cause serious disease and death.
“While we expect to see EEE-
positive mosquitoes every year, these pools were unusual and concerning because they included mammal-biting mosquitoes weeks earlier than usual,” state public health commissioner John Auerbach said.
Auerbach said the state is getting planes and insecticide ready for spraying, which he said would be done as soon as weather conditions are conducive to targeting as many mosquitoes as possible.
Aerial spraying often sparks concerns about health risks to residents and potential environmental damage to sensitive crops and waterways, but Auerbach said the chemical used carries a “minimal risk” to pets and people and that care is taken to avoid delicate agricultural areas and waterways.
Auerbach encouraged residents to continue taking precautions by using mosquito repellent and avoiding outdoor activities during peak biting times between dusk and dawn.
“Aerial spraying by itself does not eliminate the risk of mosquito-born illness,” said Auerbach. “In fact, if the public stops taking the precautions I’ve mentioned, after aerial spraying, they may be putting themselves at significant risk.”
Spraying will occur over Bridgewater, Carver, Easton, Halifax, Lakeville, Middleborough, Norton, Plympton, Raynham, Taunton, and West Bridgewater.
Auerbach said a price for spraying has not yet been determined. Last year, Dr. Alfred DeMaria, a disease specialist at the Department of Public Health, told the Globe it costs the state about $1 million each time it does aerial spraying.
But Auerbach said he has been “assured by the governor and by legislative leaders that money should never be an object with regard to taking appropriate steps to reduce the risk to the public.”
While some communities have already conducted ground-based spraying, many of the swaths of Bristol and Plymouth counties that are the most mosquito-infested remain inaccessible by ground because they lack roads, said state insect specialist Mark Buffone.
The early arrival of EEE-
infected mosquitoes is a result of the warm winter, said state veterinarian Dr. Catherine Brown.
“High temperatures . . . not only speed up the reproductive cycle of the mosquitoes, so you can get more mosquitoes faster, but it also speeds up development of the virus within the mosquitoes,” Brown said.
Southeastern Massachusetts is a natural hotbed for EEE-
infected insects, Brown said, because of the region’s plentiful white cedar and cattail swamps, which are prime habitats for the mosquitoes that carry the virus and the birds that help spread it.
No human cases of the disease have been reported this year in Massachusetts, but two people acquired EEE infections last year, including a Raynham man who died. That case and the large number of infected mosquitoes in the past two years led the Department of Public Health to adopt a more aggressive plan to fight EEE and West Nile virus, which is also transmitted by mosquitoes.
After the death of an 80-year-old Raynham man in September, town leaders, along with officials from other communities, accused the state of ignoring pleas for spraying.
Now, town leaders say they are relieved the state will be spraying their communities.
“I wish it happened earlier this year, but I am grateful it is happening now before we lose another life,” said Joseph Pacheco, a Raynham selectman. “I have always felt it is necessary and effective, and it’s welcome news to me.”
Pacheco said state officials told the town’s health agent that spraying probably would not happen there until Monday.