Hamilton remains one of a handful of communities north of Boston where the evening outdoor activity ban will remain in place after Saturday morning’s cold snap.
Earlier this week, scores of communities from the greater Newburyport area to Cape Ann lifted the ban, citing the temperatures into the 20s on Saturday morning.
On Thursday, Hamilton Town Manager Michael Lombardo said that the temperature in Hamilton dropped to 29 degrees for just an hour on Saturday morning.
When the ban was put in place on Oct. 1, the Board of Health said that it would only be lifted only after a hard freeze – temperatures of 28 degrees or less for four hours or longer – or the threat level is lowered.
The ban was put in place to protect residents from the threat of mosquito-borne illnesses such as West Nile Virus and the more serious Eastern equine encephalitis.
A total of seven human cases of EEE were reported statewide this year, including two north of Boston in Amesbury and Georgetown. Both of the residents that became infected in those towns later died. There were also 24 human cases of West Nile virus statewide, according to the state Department of Public Health.
“The (Board of Health) in consultation with the Northeast Massachusetts Mosquito Control District do not believe that the overnight temperatures for Friday, Oct. (12) were sufficient to kill off the mosquitoes and note that the threat level for Hamilton remains 'critical,'” Lombardo said. “Based on this data and information, they have not lifted the ban.”
The ban means that the bon fire and Jack O'Lantern display that is typically part of PumpkinFest on Satuday will not happen.
On Tuesday, Gloucester, Manchester and Essex all lifted the evening activity ban, according to a report in the Gloucester Daily Times. All three communities had in place the same ban as Hamilton – no organized outdoor activity from 5 p.m. to 8 a.m.
The hard frost on Saturday morning “significantly reduced the threat of mosquito borne illness,” the Manchester-by-the-Sea Board of Health told the Daily Times.
A spokesman for the Rockport School District told the Daily Times the evening activity ban had not been lifted in that town. But later, Rockport High Athletic Director Mary Ryan told the paper that the activity ban had been lifted and evening athletic practices would resume on Thursday.
In Newburyport, officials there agree with Hamilton officials, telling the Newburyport Daily News they do not think a killing frost occurred last weekend.
A community must experience a hard frost or freeze to kill mosquitoes, according to Dr. Catherine Brown, the state public health veterinarian.
“(The state Department of Public Health) recommends that a community maintain any precautions it is taking based on risk level until that first hard freeze,” she said in a prepared statement.
Brown said that according to the National Weather Service, all of Massachusetts except Suffolk County, Cape Cod and the islands experienced a hard frost on Friday night.
“Once a hard frost has occurred the risk of EEE becomes negligible though some small risk for WNV may continue as a few Culex species mosquitoes will move indoors to overwinter,” Brown said in her statement. “Therefore, rare cases of WNV have been identified even after a hard frost.”
Anne Roach, the media relations manager for the state Department of Public Health, said the “critical” risk level, the highest level, remains in place until the first hard frost but it remains up to the individual community when to list the activity ban.
In Wenham, which also put in place an evening activity ban much like Hamilton’s – except it didn’t extend to privately organized evening activities as it did in Hamilton – it was not clear Thursday where the activity ban stands. Health Agent Greg Bernard and Gerald Donnellan, chairman of the Board of Health, could not be reached for comment on Thursday morning. There was no notice on the town website that the ban had been lifted or altered and there has been no Connect-CTY message this week with any update.