Confirmed cases of Covid-19 on Martha’s Vineyard held steady at 12 for a sixth straight day Monday, but hospital leaders warned Islanders to not become complacent.

“It takes only one,” Martha’s Vineyard Hospital president and chief executive officer Denise Schepici said in an open letter to the community sent to Island newspapers. “One person who is COVID-19 positive. One person, in our community who shows no symptoms and innocently is unaware he or she is carrying the novel coronavirus. It takes only one to assist the spread and infect scores of others — without knowing.”

As of Monday the hospital had done 206 tests, with 188 negatives, 12 positives and six pending. No one was hospitalized Monday with Covid-19.

Statewide, a surge in cases continued Monday, with 1,392 new cases for a total of 26,867. There were 88 new deaths reported, bringing the total death toll from the disease to 844.

The Island remains in a state of nearly complete shutdown, with stay-at-home orders in effect in every town, and construction halted until April 21.

“This virus is everything we as Islanders are not,” Ms. Schepici wrote in her letter. “It promotes isolation and protection from each other. Whereas we are a diverse community, bonded in our love for an Island and its treasures that we all cherish.

“However, in order to fight back against COVID-19, we will need to make sacrifices and we will need to make those decisions together.

“No one likes to say, please stay home. But we do so as a request to support our entire community. We greatly appreciate all those who have heeded our call and thank everyone for embracing a spirit of unity with a singular focus of taking care of one another for the safety of one another.”

A strong spring storm moving in from the south began buffeting the Vineyard late Monday afternoon, canceling some ferry service. High winds were in the forecast for overnight.