Covid-19 case numbers have increased sharply on the Vineyard just as the Island prepares for the weekend’s July Fourth festivities, prompting public health officials to issue advisories this week for people to take precautions.

According to the Martha’s Vineyard boards of health, 100 cases were reported this week, with the number of daily cases trending upwards.

In light of the rising numbers, as well as three hospitalizations in the past week, the CDC classification system designates the Vineyard as high risk, Tisbury health agent Maura Valley said in her daily emailed report on case numbers Thursday.

At a press briefing on Wednesday morning, leaders at the Martha’s Vineyard Hospital urged the public to be extra cautious amid the influx of summer tourists.

“We know it’s here, and it’s very contagious,” said hospital president and chief executive offficer Denise Schepici said, reporting she herself had recently come out of quarantine due to Covid-19.

Ms. Schepici and chief nurse Claire Seguin confirmed that the new Omicron subvariants BA.4 and BA.5 are present on the Island. They said the subvariants are resistant to immunity, both from vaccines and previous infection.

Due to the surge, health officials asked members of the public to avoid the use of the hospital emergency room for minor ailments in an attempt to protect staff from infection.

“We are fragile, and we really need to protect people at the hospital,” Ms. Seguin said.

She and Ms. Schepici reported there had been significant numbers of infections among hospital staff, with 14 in April, 29 in May and 36 so far in June. Additionally, they said there had been eight cases among staff at Windemere, the Island’s only nursing home.

Meanwhile, on top of the ongoing Islandwide labor shortage, infections among staff have put a squeeze on businesses, with a number of restaurants forced to temporarily close in recent weeks. According to Caroline Cooney, executive director of the Martha’s Vineyard Chamber of Commerce, business are working to adapt to the trending cases.

“I have seen some businesses that I know did close due to multiple staff members having Covid-19,” Ms. Cooney said. “For the most part, it is business as usual. People are rolling with it and closing if they need to. They are doing the best they can.”

Janet Hathaway, assistant to the Edgartown board of health, also confirmed this week that many businesses that are housing their staff are reporting cases.

Free at-home test kits and K-95 masks are available at every Island town hall. Health officials urged those who test at home to report their results, warning that the likelihood for at-home antigen tests results to go unreported leads to incomplete public health information.

Chilmark health administrator and inspector Marina Lent echoed the level of concern expressed by hospital leaders this week, describing the rise in case numbers as dramatic and citing high transmission in the community.

Interpreting the lack of increased concern among the broader public, Ms. Lent argued that due to minimal immediate symptoms among those who are vaccinated, Covid-19 risks are generally underrated.

“Long Covid concerns me a lot. People are feeling a lot more casual about Covid because symptoms have been mild, but these long Covid symptoms are not mild,” Ms. Lent said.

She also expressed some concern about the upcoming Independence Day festivities, specifically the large parade in Edgartown.

“Outdoors shoulder to shoulder, you are taking a risk there. We have no guarantees of safety, but people can reduce their risk a lot. Looking for a less crowded spot, wearing a mask,” Ms. Lent said. “If I was going to the parade I would wear a mask there.”

At the briefing, hospital leaders also gave an update on vaccination rates for Dukes County: 95 per cent of county residents have had a first shot, while 59 per cent have had two shots plus a booster. In addition to its ongoing vaccine clinic, the hospital is also offering pediatric vaccines for children six months to five years old. Vaccination appointments can be made online on the hospital website at mvh.org.

Anyone who tests positive using a home test kit is asked to report it at rapidtestmv.org.

Thomas Humphrey contributed reporting.