A spike in Island Covid cases has closed a bevy of businesses at the peak of summer and left two patients hospitalized with the virus for the first time since early spring.

TestMV — the Island’s free testing site — has also received approval to move from the West Tisbury School to the Agricultural Hall, with the facility seeing a rise in test recipients in recent weeks.

Health agents have reported 54 new Covid-19 cases since Sunday, August 8, with 10 reported on Tuesday, 13 on Wednesday and now 18 new cases reported Thursday. The 54 cases reported over the past five days come after case levels reached near-zero totals at the beginning of the summer.

But they have spiked in recent weeks, peaking during the traditionally busiest weeks on the Island.

At least four Edgartown restaurants — Alchemy, The Port Hunter, Covington and The Newes From America — have been closed at various points this past week due to Covid-19 cases among staff. The Port Hunter and The Newes From America pub have reopened; the Covington and Alchemy restaurants remain closed through next week, according to signs and Instagram posts.

Edgartown health agent Matt Poole said in an interview that the closures were part bad luck, part the unfortunate reality of working in the food service industry on Martha’s Vineyard, where employees often live in close quarters and work in multiple establishments.

“Part of what you’re seeing here are employees working in more than one establishment,” Mr. Poole said. “Employee housing is also a significant complicating factor. The transmission that you’re seeing is often happening in housing, not in the workplace.”

Two patients were hospitalized with Covid-19 at Martha’s Vineyard Hospital as of Thursday afternoon, according to hospital spokesman Marissa Lefebvre. A patient who was hospitalized over the weekend in serious condition remains hospitalized in the same condition. The patient had received only one vaccine dose.

The second patient was hospitalized Wednesday morning in fair condition, Ms. Lefebvre said. She said in an email Thursday that she could not share the patient’s vaccination status.

The hospital classifies patient condition as good, fair, serious or critical, in increasing order of severity.

Concerns about the rising incidence of Covid cases, about half of which have occurred in fully vaccinated people, has boosted traffic at Test MV, which offers free testing for people without symptoms, said Mary Breslauer, a spokesman for the test site.

“We’ve been getting higher numbers, numbers that correlate with last summer,” she said. “A lot of this seems to be a direct result of cases at the restaurants.”

Mondays, Wednesdays and Fridays, when Test MV takes reservations by phone, have been the busiest, she said, with up to 150 people per day. People can also reserve a testing slot by registering online. Details are at ihimv.org. Breslauer noted that the turnaround time for test results is now 2-4 days because of increased volume at Quest Diagnostics labs, which processes the tests.

West Tisbury selectmen agreed Wednesday to allow Test MV to move its testing site to the Ag Hall later this month from the West Tisbury School, where it has been located since June.

Ms. Breslauer said the organizers of the site thought at one time they might discontinue testing after Labor Day, but rising cases have only increased need.

“It’s clear we need to stay open. There needs to be an operational test site,” Ms. Breslauer said.