Three employees of biotech giant Biogen tested positive for the new coronavirus after attending a management meeting with about 175 co-workers over two days last week at a Boston hotel, the company said Thursday.
None of the three infected employees lives in Massachusetts, but the location, size, and duration of the gathering raised concerns about a wider outbreak of the infection in the state. Officials at the Marriott Long Wharf Hotel, where the Biogen event was held, didn’t return a phone call seeking comment.
On Wednesday Biogen sent an e-mail telling all employees who attended the management meeting to work from home until March 16, regardless of whether they had symptoms, according to David Caouette, a spokesman for the Cambridge-based company.
Before Biogen disclosed the infections, Massachusetts had three cases of Covid-19, the illness caused by the virus — one confirmed and two presumptive, according to the state Department of Public Health.
The second presumptive case was announced Thursday, a Middlesex County woman in her 60s who recently traveled to Europe, including northern Italy. She was symptomatic but did not require hospitalization and is recovering at home, health department officials said.
Public Health Commissioner Monica Bharel urged Massachusetts residents to follow the guidelines of the Centers for Disease Control and Prevention for dealing with the disease.
“While the risk to Massachusetts remains low, residents should make sure they and their families are well-informed about Covid-19 and heed the CDC’s updated international travel health alert,” she said.
As of Thursday evening, there were 230 confirmed coronavirus cases in the United States and 14 deaths — 13 in the Seattle area and one in California, according to a database run by Johns Hopkins University using official reports from around the world. There were more than 98,000 cases globally, with nearly 3,350 deaths.
Earlier on Thursday, officials in Tennessee confirmed the state’s first Covid-19 case, a man who had recently returned from traveling to Boston. He has a mild illness and is isolated at his home in Williamson County.
Governor Charlie Baker said Thursday night that he was “under the impression at this point in time” that the Tennessee patient is one of the infected Biogen employees.
“We’ve been talking to the city’s department of public health and to the folks at Biogen and to others about that particular situation,” Baker said at the Old South Meeting House, where he spoke at a ceremony marking the anniversary of the Boston Massacre. "And obviously we’re going to work through the details on that over the next day or two.”
The other two Biogen employees reside in Europe, the company said.
Caouette, the Biogen spokesman, declined to say when Biogen became aware of the infections or provide other specifics. Several other attendees of the management meeting on Feb. 26 and 27 had flu-like symptoms afterward.
The company has also contacted officials at the hotel that hosted the meeting, Caouette said.
All of “these individuals are doing well, improving and under the care of their healthcare providers,” the company said in a statement.
“Protecting our employees and our communities is our priority,” said Biogen, which has 2,400 workers in Massachusetts and 7,500 worldwide. “Biogen has been in regular contact with the relevant public health officials since the time the first cases of illness were reported.”
Since January, Massachusetts has tested 25 residents for the coronavirus, including the three identified by the health department as having the disease, according to the state. As of Wednesday, 719 people have been subject to self quarantine; about 249 are still currently quarantined, state officials said.
Citing advice from the state, MIT said Thursday that it had suspended all international school-related travel for faculty, students, and staff.
“Rare exceptions will be considered,” president Rafael Reif said in an e-mail to the MIT community. He also said MIT was discouraging personal international travel.
Baker said that the coronavirus situation in Massachusetts is evolving but “still relatively low risk,” and he encouraged residents to wash their hands and be hygienic and to stay home if they get sick.
At the Old South Meeting House, Baker said Massport is taking additional precautions at Logan Airport based on guidance from the CDC. He added that domestic travel, based on current guidance from the federal government, “is perfectly appropriate.”
Correction: An earlier version of this story misstated the number of Covid-19 deaths in the Seattle area. Thirteen people have died there.
Jaclyn Reiss, Nestor Ramos, and Hanna Krueger of the Globe staff contributed to this report.