LENOX – With a record 27 active coronavirus cases, Lenox is now the only Berkshire County community in the statewide high-risk “red zone,” according to the Massachusetts Department of Health’s weekly report released Friday night based on data through Wednesday.

The state’s updated community-level data on the pandemic lists any town with a population under 10,000 and more than 25 cases in the highest-risk category. There are 80 other cities and towns in the “red zone,” all of them east of the Berkshires.

The outbreak in Lenox, where the population is about 5,000, primarily involves a cluster of cases at the Kimball Farms Nursing Care Center on Sunset Avenue, where there are 17 active cases, Tri-Town Health Department Executive Director Jim Wilusz told The Eagle on Saturday. Ten other cases in Lenox are scattered throughout the community, he said.

“It’s a significant concern, we don’t know how it happened,” Wilusz said.

The overall numbers are fluid “moving targets” from day to day, he cautioned. “We knew this was coming, it was only a matter of time after Halloween.”

Tri-Town Health’s current tally of active cases at Kimball Farms Nursing Care Center differs from the Berkshire Healthcare online count, updated on Friday. That report showed 25 confirmed active cases among residents at the nursing center, and six more involving staff, said Lisa Gaudet, vice-president of business development and marketing for Berkshire Healthcare, which owns the Kimball Farms facilities.

In addition, four employees at the Kimball Farms Life Care retirement community and the PineHill Assisted Living facility, both at 235 Walker Street, were listed among current cases, Gaudet said Saturday.

If Lenox continues in the red zone for three consecutive weeks, the outbreak will then require a rollback to phase 3, step 1 of Gov. Charlie Baker’s statewide reopening plan, Wilusz explained.

That would mean outdoor gatherings will be limited to 50 people, down from 100. Gyms, libraries and museums would need to reduce their patronage to 40 percent of normal capacity.

But, he emphasized, there will be no impact on indoor dining at the town’s restaurants, most of which remain open, though some offer takeout and/or delivery only.

“We’re not seeing restaurants causing virus transmission and spread,” Wilusz said, referring to eateries not only in Lenox but also Lee and Stockbridge, the other towns under Tri-Town Health’s regional portfolio.

As of Saturday, Lee had 17 active cases, a record for the town, placing it in the state’s yellow zone for the reporting week that ended Friday. Stockbridge has 5 active cases, still in the state’s lowest-risk gray zone.

“We understand the dynamics of the economy,” Wilusz said. “Restaurants are doing a really good job, they’re in good compliance, working with us.” Several Lenox restaurants imposed temporary shutdowns earlier this month, primarily because of positive tests involving staffers, but have since reopened.

However, Wilusz pointed out, “we’re going into a very tough, challenging post-Thanksgiving period. We don’t know where we’ll be in a month. We’re in the middle of a second surge, but we’re on top of cases and our nurses and other staff are working hard. Until we know about vaccine distribution, we have to be prepared as a county. Talking about a vaccine doesn’t mean we should let our guard down.”

According to state data released Friday, Lenox has had 63 confirmed COVID cases since March 1, including 31 in the last two weeks. The current positive-test rate is 3.41 percent, based on 909 tests in the past 14 days, compared to a 3.05 percent statewide rate.

The statewide total of 81 communities in the highest-risk red zone is up from 62 towns and cities from the previous week, 30 the week before, and 16 a month ago.

The fluctuating numbers reflect a major, abrupt change in the way the state Department of Public Health measures the risk of coronavirus transmission.

To qualify for the red category under the new metrics, communities with populations under 10,000 must have more than 25 cases. For mid-size communities of between 10,000 and 50,000 people, they must have an average of more than 10 cases per 100,000 people and a positive test rate of more than 5 percent. And for larger communities of greater than 50,000 people, they must have more than 10 cases per 100,000 people and a positive test rate of more than 4 percent.

Previously, the state used the number of cases detected on average each day over two weeks to determine if Massachusetts communities are at high risk for coronavirus transmission. The new list factors in population size and positive test rate.

The following 81 communities are in the highest risk level as of Friday:

Attleboro, Barnstable, Bellingham, Berkley, Blackstone, Boxford, Brockton, Chelmsford, Chelsea, Chicopee, Clinton, Dartmouth, Dighton, Douglas, Dracut, East Longmeadow, Edgartown, Everett, Fairhaven, Fall River, Fitchburg, Framingham, Freetown, Gardner, Georgetown, Hampden, Haverhill, Holyoke, Hopedale, Lancaster, Lawrence, Leicester, Lenox, Leominster, Littleton, Lowell, Ludlow, Lunenburg, Lynn, Malden, Marion and Mendon.

Also, Merrimac, Methuen, Middleton, Milford, Millbury, Monson, New Bedford, Norfolk, Oak Bluffs, Paxton, Peabody, Rehoboth, Revere, Rutland, Salisbury, Saugus, Seekonk, Shirley, Somerset, Southbridge, Southwick, Springfield, Sterling, Sutton, Swansea, Taunton, Templeton, Tisbury, Tyngsborough, Upton, Uxbridge, Wenham, West Boylston, West Springfield, Westminster, Westport, Whitman, Winchendon, and Woburn.

Information from NBC Boston 10 and the Boston Globe was included in this report. Clarence Fanto can be reached at cfanto@yahoo.com, on Twitter @BE_cfanto or at 413-637-2551.