Submarine builder Electric Boat has reported more than 100 COVID-19 cases among its employees in the last week alone.

As of 5:30 p.m. Tuesday, the company's case summary showed 408 employees have tested positive for COVID-19 since the start of the pandemic in March, and 58% of the cases have been reported since Nov. 1. The confirmed case total includes employees working in Connecticut and other locations.

“I’m very concerned about this trend as I know you are,” EB President Kevin Graney said in a Nov. 13 announcement to employees. “We understand that cases are rising in the community and that means that we cannot let our guard down — we must adhere to all of the measures we’ve been taking for the last several months.”

Southeastern Connecticut also has seen a surge in cases in recent weeks. The state has reported more than 1,000 cases in New London County, both confirmed and probable, since the start of this month.

The governor's office reported that the county has had 4,828 confirmed cases as of Tuesday, up by 62 since data was reported Monday, and 140 probable cases. Confirmed associated deaths stood at 120, while probable related deaths stood at 35, both unchanged from the previous day.

Lawrence + Memorial Hospital in New London had 23 COVID-19 patients Tuesday, while Westerly Hospital had six. Backus Hospital in Norwich had 19, according to Hartford HealthCare, which owns it.

Graney, in his announcement, reiterated that employees should not come to work if they feel sick. While the company has a “highly committed workforce who wants to be here everyday ... we’ve seen real-world evidence of clusters of skilled shipbuilders infected or thought to be a close contact who must be tested, because one of their co-workers came to work with symptoms,” he said.

He also reminded employees to social distance, particularly when they are eating and don’t have their masks on, and that mask-wearing is a requirement for all employees on EB property.

With Thanksgiving next week, seen by public health officials as a time when COVID-19 cases could surge even more if families gather together indoors as usual, Graney urged employees to rethink their plans.

“My wife and I have changed our traditional extended family Thanksgiving,” he said. “We’ll celebrate together at home — with a much smaller turkey — and will do a brief visit with my wife’s parents, from a safe distance, later in the afternoon.”

The company, deemed an essential business and thus allowed to remain open throughout the pandemic, given its work in support of national security, has instituted a number of changes to create a safer workplace for employees. However, early in the pandemic many employees expressed dissatisfaction at what they said was an insufficient and slow response by the company to keep them safe.

About 4,000 of EB’s 17,000 employees are working from home — a number that has remained unchanged in the last six months. EB instituted voluntary, companywide testing in May.

Graney was among the early wave of employees who tested positive for COVID-19. He announced to employees in early April that he'd tested positive. He has said his case was not severe.

j.bergman@theday.com