Massachusetts public health officials may be quicker to consider aerial spraying against mosquitoes this season, under a new plan detailed Wednesday.
The Department of Public Health said it was revising its plan regarding Eastern equine encephalitis, an often fatal mosquito-borne illness, because of indications the risk from infections may be increasing.
Under the new guidelines, officials will consider aerial spraying of insecticide in an area when just one mosquito of the type that typically bites humans or other mammals is found infected with EEE. Current rules call for aerial spraying to be considered after two such insects are found.
The new plan also calls for more targeted spraying in specific areas as an alternative to covering a full region. And officials said they will also be exploring the use of additional airplane-based spraying equipment to help respond quicker and with more precision when a risk is pinpointed.
“These revised guidelines will ensure that we mount the most effective, science-based approach to reduce the risk of disease spread by mosquitoes among our residents,” John Auerbach, state public health commissioner, said in a statement.
The department said aerial spraying is just one aspect of a multi-pronged approach to reduce risk of infection from EEE.
Officials said that the pesticide used, Sumithrin, which is combine with Piperonyl Butoxide, has been sprayed for several years and is a less toxic than ones used in the past.
“It is applied at a very low volume, less than an ounce per acre,” said Kevin Cranston, director of the agency’s bureau of infectious disease.
Cranston also said the pesticide is sprayed at night, when adult mosquitoes are buzzing around but other insects, such as bees, are not active to minimize the potential harm.
The health department said it sought advice on its new guidelines from a panel of experts, which included specialists in mosquito control, ecology, climate change, and infectious disease, and public health representatives from Southeastern Massachusetts -- the area hardest hit by EEE.
The state’s action comes in the wake of pressure applied by officials from the South Shore last fall and winter, following the death of 80-year-old Raynham resident Martin Newfield, who was infected with EEE in late August and died in early September.