After three straight weeks in the red zone, the town of Tisbury has been required by the state to revert back to stricter coronavirus regulations as Island health agents reported 11 new Covid-19 cases on the Vineyard Tuesday.

In a daily coronavirus update, health agents said that eight of the new cases were tested at TestMV and three came from Martha’s Vineyard Hospital. The Island has now eclipsed 300 positive laboratory confirmed tests, reporting 25 cases since the Friday after the Thanksgiving holiday, 108 over the past two weeks and 309 total.

Case numbers have been increasing at a steady clip on the Island for the past month, leading to the introduction of tighter construction rules in five Island towns last week, and the designation of all three down-Island towns as high risk communities for Covid-19 spread. Edgartown has now been designated a high risk community by the state for two weeks running, and Oak Bluffs was included on the list for the first time last week.

But Tisbury’s third consecutive designation has forced the town to return to step one of the third phase of Gov. Charlie Baker’s four-phase reopening plan, and marks the first time an Island town has had to roll back reopening after businesses and other public spaces shuttered this spring.

Tisbury has now recorded 88 total coronavirus cases since the pandemic began, the most of any Island town. According to the state Department of Public Health, 33 cases have come in the past 14 days, and the town has recorded more than 25 cases per 14 days for the past three weeks.

With the new rules, all indoor performance venues in the town are required to close, and museums, gyms and libraries must transition from 50 per cent occupancy to 40 per cent occupancy. Outdoor gathering limits have been reduced from 100 to 50 people, and outdoor theatre venues have been reduced from 50 per cent capacity to 25 per cent capacity, with no more than 250 people.

The rules took effect on Monday.

In an email to the Gazette, Tisbury health agent Maura Valley confirmed that the Martha’s Vineyard Film Center is not considered an indoor performance venue and would be able to stay open with 50 per cent occupancy. The Vineyard Playhouse, a theatre venue in downtown Vineyard Haven, would be required to close; however, it has not opened since the pandemic began in March.

The Mansion House gym, the town library and the Martha’s Vineyard Museum, all located in Tisbury, will be required to lower capacity to 40 per cent, Ms. Valley confirmed.

Ms. Valley was not immediately sure how long the town would have to remain in step one of the third phase of the reopening plan, but said she had reached out to the state for guidance.

According to an executive order issued by Gov. Baker earlier this summer, a community must revert to stricter guidelines when it has been designated in the red category for three consecutive weekly DPH public health reports. Towns under 10,000 people -- including all six Island towns -- are considered in the red if they record more than 25 cases over a two-week period.

Although Tisbury is the first Island town to be considered high risk for three straight weeks, Edgartown has been in the red category for two weeks and Oak Bluffs for one week. Edgartown has recorded 74 cases since the pandemic began, and 38 in the past two weeks, while Oak Bluffs has recorded 50 total cases, and 36 in the past two weeks.

At an Oak Bluffs board of health meeting, health agent Meegan Lancaster said that the Island’s 14-day running total of positive cases is 108, slightly down from the peak reported two weeks ago but still a large number for contact tracers.

“The number of close contacts these cases are generating is quite substantial. I don’t think we’re really over the hump there,” Ms. Lancaster said.

Martha’s Vineyard Public Schools are now reporting one new case in the Oak Bluffs school and 11 students overall who are in quarantine due to a positive test; three in the regional high school, three in the Oak Bluffs school, four in the Edgartown school and one in the Tisbury school. Another five teachers are quarantining due to a positive test, and 42 students or faculty are quarantining as close contacts of a reported positive case.

“Contact tracing is ongoing on for any new positives,” the school update posted on the superintendent’s website states. Previous updates, including Monday’s, have stated that no virus spread had occurred in the school.

Statewide, the Department of Public Health reported 2,845 new cases on Tuesday and 30 new deaths. There are now 1,191 patients currently hospitalized with the virus, and 239 in the ICU. Both numbers have been steadily climbing since September. The state has now reported more than 221,000 cases and 10,542 deaths.

Aaron Wilson contributed reporting.