SHIRLEY – E-alerts and website warnings informed residents last week that the town was on EEE (Eastern Equine Encephalitis, or “triple-E virus) alert after mosquitoes infected with the virus were found on Mt. Laurel Circle.

As a result, the Massachusetts Dept. of Public Health (MDPH) upped Shirley’s EEE-risk level to moderate.

The upshot was that spraying was set for Tuesday, Aug. 27, at night, from 8 pm to 12, targeting the spot where infected mosquitoes were found and the area within a mile radius.

Fast action, all things considered. But it was no automatic response. In a on-line memo last week, Town Administrator Mike McGovern spotlighted preliminary work that went on behind the scenes.

Responding to the news from MDPH, the selectmen directed McGovern and his staff to “take the necessary steps” to protect residents from the dangerous EEE virus, he said.

“We will ask the State to begin spraying at the very earliest date,” the memo reads, in part. But “certain steps” had to come first.

Wheels started turning when state and regional health officials notified the selectmen that MDPH had found virus-infected mosquitoes in samples collected from a test site: Mt. Laurel Circle, off Lancaster Road near Route 2 and the Lancaster town line, a mile from the Lura A. White Elementary School.

On Wednesday, August 21, the Nashoba Associated Boards of Health notified the town that the Massachusetts Department of Public Health (MDPH) had detected EEE virus in mosquitoes collected from Shirley and that the bugs were a “mammal-biting” species, raising the EEE-risk level in Shirley to “moderate,” McGovern said.

Sketching a flow-chart of agencies he could reach out to for help, he said the Reclamation and Mosquito Control Board (SRMCB) is in charge of “sanctioned” mosquito control in Massachusetts, with branches across the state via 11 regional programs, including the Central Massachusetts Mosquito Control Program, or CMMCP.

Shirley isn’t one of the communities served by the program,  having voted to opt out of the program at a 1993 Town Meeting.

The program not only tests for infected mosquitoes in member communities on a regular basis, it also provides a series of preventative measures, including destruction of mosquito larvae in breeding areas.

When McGovern reached out to the program, he learned there’s an “emergency provision” that the town – as a non-member – could apply for: “adulticiding.” Basically, spraying to kill adult mosquitoes.

McGovern then scheduled a conference call with the program director to talk procedure and assembled an audience consisting of his Executive Assistant, Mike Gibbons; DPW Director Brandon Kelly, Conservation Agent Mike Fleming and Board of Health clerk Sandi Hill.

First step: Submit a letter requesting the emergency service to state and district organizations involved. After the request was approved, spraying was set for Tuesday, August 27 from 8 pm to midnight.

The delivery system consists of a truck-mounted sprayer that emits a mist of “low-active” solution, which is about four-percent pyrethroid, a known bug-killer. It activates fast and doesn’t last long.

According to an emergency phone-alert issued by the MDPH over the weekend, residents in the spray-zone, a mile around Mt. Laurel Circle, were  advised to stay indoors Tuesday night, close windows, and turn off A/C. The stay-indoors advisory also applies to pets.

The call didn’t include special precautions for beekeepers, but it might be a good idea to cover hives. It did, however, offer advice to avoid mosquito bites, such as scheduling outside activities during the day (dawn to dusk) and when out at night, wearing long-sleeves, long pants and insect repellent with DEET.

A similar shout-out could also go to neighboring Harvard, which, like Shirley, opted out of the program and was notified last week that EEE-infected mosquitoes were found in that town. The Harvard Board of Health scheduled an emergency meeting this week to discuss the EEE risk and how to address it.

Devens, whose boundaries encompass parts of Ayer, Harvard and Shirley, does belong to the program.

MassDevelopment, the state agency that governs Devens, notified residents and businesses in that community of the EEE-threat last week as well and advised them to “take precautions when outdoors.”

Ayer Shirley Regional School District Superintendent Mary Malone reacted to the news of Shirley’s EEE issue in an e-mail message to parents that included a forwarded Press Release from the town .

With school set to open this week and because the LAW elementary school is in the mosquito-spraying target zone, students there wouldn’t have outdoor recess for two days, this week and next. “There will be no outside recess (at LAW) on Thursday, August 29 or Tuesday, Sept. 3,” the notice states. (No school on Friday, Aug. 30 or Monday, Sept. 2. )

There have been no area cases of EEE reported. But information on the state website indicates the ado in this instance isn’t over-kill. Far from it. Eastern Equine Encephalitis is a serious threat and the virus is dangerous. It shows up every year, seasonally. Two kinds of mosquitoes carry it: bird-biting and mammal-biting, like those found here.

At the next level, a high risk scenario includes environmental factors optimal for mosquito-breeding.

Standing water, for example. Personal protection advisories include repairing door and window screens and getting rid of water that pools in outdoor receptacles such as in bird baths, flower pots and old tires.

In high risk cases, aerial spraying might be a reasonable response, to reach breeding areas not accessible by truck.

No flying crop dusters are anticipated around here, however. One truck, one date: Tuesday, Aug. 27, from 8 pm to midnight. Again, the target zone is Mt. Laurel Circle and the area within a mile radius.

More information is available on the state website or may be obtained from the State Reclamation and Mosquito Control Board or on the website www.mass.gov/dph/mosquito