The danger of Eastern equine encephalitis being spread by mosquitoes in a section of Southeastern Massachusetts has risen to a level that will require aerial insecticide spraying this week.
The state Department of Public Health has designated 20 communities as high risk. Spraying will occur in targeted areas in Bristol and Plymouth counties beginning Thursday, authorities said. EEE has been found in 164 samples this year, about half from species of mosquito capable of spreading the virus to people.
No human or animal cases of EEE have been detected so far in Massachusetts this year. The last human case in the state occurred in 2013.