The number of reported cases of coronavirus in Massachusetts has jumped to eight, including five cases connected to a conference held in Boston last week, officials said Friday.

That includes one confirmed case and seven that are awaiting final confirmation from the Centers for Disease Control and Prevention.

Two Boston hospitals are testing dozens of people who were at a hotel that hosted a conference now linked to several cases of coronavirus. City and state officials spoke about those cases at a briefing, telling the public to stay calm and take steps to protect themselves.

Health officials announced Friday that three Boston residents and two residents of Norfolk County who attended a meeting organized by biotech firm Biogen last week at the Marriott Long Wharf hotel are presumed to have contracted COVID-19.

The presumed cases from Boston are two women and a man in their 40s, said Marty Martinez, the city's chief of health and human services. All three are self-isolating at home, he said, adding that two are showing symptoms of the virus while the other is not.

Boston's chief of health and human services, Marty Martinez, gives an update on the number of coronavirus cases in Boston on Friday, March 6, 2020.

State Human Services Secretary Marylou Sudders confirmed that the two Norfolk County residents who attended the conference were presumptive positive cases as well.

The people with the two remaining presumptive cases in Massachusetts had recently traveled to northern Italy.

State health officials did not say which city or town each individual lives in.

Properly sanitizing your phone can help protect against illness, including coronavirus.

Marriott said they were informed by health officials of coronavirus cases involving individuals who attended a group meeting between Feb. 24 and 27 at the Marriott Long Wharf. They said they are working with health officials and following their guidance.

Martinez said the Boston residents who are presumed cases had been in "close contact" with one of the confirmed cases. Health officials are looking for people who were in direct contact with the presumed new cases.

Brigham and Women's Hospital said Friday afternoon that the Department of Public Health asked them to test individuals who attended the Biogen conference.

"We have activated our central ambulatory screening and testing plan and will test patients outside the hospital in the ambulance bay," a hospital spokesperson said in a statement.

The hospital said emergency personnel will manage the testing, and those being tested will then return home to await results. They said they do not anticipate an influx of inpatients or any impact to hospital operations or normal patient activity.

Patients are also being tested at Massachusetts General Hospital, according to the Boston Public Health Commission.

Several local restaurants say they are struggling with uncertainty brought on by the coronavirus outbreak.

Friday morning, students at two schools in Wellesley were dismissed early after school officials alerted parents that they had learned that a Wellesley resident who tested positive for COVID-19 — the disease caused by the new coronavirus — is also a parent of children who attend the two schools, Upham Elementary School and Wellesley Middle School.

Wellesley school officials said the goal of the early dismissal was to clean and sanitize the schools. No children were showing symptoms, they said.

The state's first confirmed case came at the beginning of February, when a male student at the University of Massachusetts Boston who had traveled to Wuhan, China, sought medical care after his return from the virus's epicenter. Health officials said the student is continuing to recover at home.

Gov. Charlie Baker said the general public remains at low risk for the coronavirus, but added that the state is "planning and preparing for the potential of more cases to develop."

State health officials said they currently have enough tests for the virus and have been processing about 40 to 50 a day at the state lab. They said they can get test results in 24 hours.

More than 700 Massachusetts residents have been quarantined as a precautionary measure.

Health officials say a man from Tennessee who tested positive for coronavirus traveled through Boston's airport.

Of those quarantined, 470 people have completed monitoring and 249 remain in isolation, according to health officials.

The Baker administration this week urged colleges and high schools to cancel all upcoming international trips in a bid to prevent the spread of the virus. He added Friday that officials have urged organizers of all large-venue gatherings to take "extra universal prevention" precautions such as disinfecting all surfaces and and providing personal hygiene products to attendees.

"It's important that everyone uses common sense on this particular issue," Baker said.

Rhode Island and New Hampshire have also each had two presumptive positive cases of their own. To this point, there have been no reports of positive coronavirus cases in Connecticut, Maine or Vermont.

The Associated Press contributed to this report.