Coronavirus outbreak is officially declared a pandemic, as events, schools are closed and Dow continues to plummet

Dr. Anthony Fauci (left), director of the National Institute of Allergy and Infectious Diseases, and Dr. Robert Redfield, head of the Centers for Disease Control and Prevention, appeared before the House Oversight Committee on Capitol Hill on Tuesday.Pete Marovich/The New York Times

The World Health Organization on Wednesday declared that the novel coronavirus spreading across six continents can now be called a pandemic, and President Trump announced he was sharply restricting travel from Europe to the United States in an attempt to limit the spread of the disease.

Massachusetts cases of the coronoavirus increased slightly to 95 Wednesday, from 92 the day before, and the number of state residents who have been subject to quarantine topped 1,000. Worldwide, the number of cases are more than 120,000 while the number of deaths exceed 4,300.

Trump’s announcement was a sharp departure from his earlier attempts to downplay the threat. He blamed Europe for not acting quickly enough and contended that US clusters were “seeded” by European travelers.

“We made a lifesaving move with early action on China,’’ Trump said in a rare Oval office address. ‘‘Now we must take the same action with Europe.”

Trump announces travel ban for foreign travelers from many European countries

President Trump announced a ban on travel from many European countries for the next 30 days beginning Friday at 11:59 p.m.

Trump said the restrictions won’t apply to the United Kingdom, and there would be exemptions for “Americans who have undergone appropriate screenings.’’ Homeland Security officials later clarified that the new travel restrictions would apply only to most foreign nationals who have been in the ‘‘Schengen Area’’ at any point for 14 days before their scheduled arrival to the United States. The area includes Italy, German, Greece, Austria, Belgium, and other countries. It doesn’t apply to legal permanent residents, immediate family of US citizens or others ‘‘identified in the proclamation.’’

The suspension will start Friday.

Few aspects of life had been left untouched by the virus. It officially ended the 11-year bull market Wednesday, with the Dow now 20 percent from its peak and in bear market territory. In Boston, the MBTA began to see a drop in ridership, as employers ordered their employees to work from home. Boston area colleges announced they would be switching to remote learning, and many told students to leave campus.

A key health official issued dire warnings. “The bottom line: It is going to get worse,” said Dr. Anthony S. Fauci, director of the National Institute of Allergy and Infectious Diseases.

He told a congressional hearing Wednesday that large gatherings across the country should be canceled, part of a virtually unprecedented effort to limit the spread of the disease.

“We are at the point where we could have our hospital system in crisis in three or four weeks, and what we do now will affect them,” Marc Lipsitch, professor of epidemiology at Harvard T.H. Chan School of Public Health and director of the Center for Communicable Disease Dynamics, said in a telephone briefing Wednesday.

Although the WHO declaration of a pandemic merely confirmed what many epidemiologists had believed, it added fire to calls for strong measures to control the virus’s spread.

“I hope it adds urgency to efforts to mitigate [the epidemic] because those efforts need urgency,” Lipsitch said.

He noted that the epidemic can explode in a flash: Italy went from a handful of cases to 10,000 in three weeks, and its health care system has been overwhelmed.

He favors eliminating all gatherings of more than 25 people in a room, saying that 25 is not a “magic number” but “a good conservative one.” That means shutting down cinemas and theaters and stopping church services.

And he thinks the Boston Marathon, scheduled for April 20, should be canceled, even though it’s not known how easily outdoor gatherings promote disease transmission. “We need to err on the side of caution,” he said.

Some Massachusetts organizations are indeed choosing caution.

One of the year’s most significant — and unique —gatherings in Boston joined the list of canceled events.

The massive Ace Comic Con entertainment convention, which features such A-list movie stars as Chris Evans and Tom Hiddleston and was expected to attract more than 30,000 fans to the Boston Convention Center and Exhibition Center on March 20-22, has been postponed, organizers said Wednesday evening.

Meanwhile, four more major universities in Massachusetts announced Wednesday they were ending in-person classes and shifting to online or remote learning.

The University of Massachusetts system (with 75,000 students), Boston University (35,000 students), Northeastern University (22,000 students), and Boston College (15,000 students) all announced such plans, which will drastically curtail campus life and hit the bottom lines of nearby businesses.

They joined a host of other area colleges moving their spring classes online. (Clark University in Worcester was bucking the trend, declaring in a message to parents that the transmission risk is low and “there are no near-term plans to close residence halls or direct students to leave campus.”)

Tufts Medical Center has started to cancel elective procedures and nonurgent appointments to reduce the number of people at the hospital and free up beds for coronavirus patients.

The John F. Kennedy Presidential Library and Museum in Dorchester closed until further notice because two library employees attended a conference last week where other attendees were confirmed to have come down with the coronavirus.

Bain Capital is closing its headquarters in Boston’s Hancock Tower and sending 700 employees to work at home because an employee developed symptoms of Covid-19 after an international trip, even though the illness hasn’t been confirmed by laboratory tests.

Vertex Pharmaceuticals, the Boston-based biotech best known for its drugs for cystic fibrosis, on Tuesday told employees to begin working remotely if their jobs allow, and Tango Therapeutics, a Cambridge biotech, did the same.

At the Encore Boston Harbor resort, members of the hotel management staff are taking the temperatures of guests who are coughing, sneezing, or showing other symptoms of illness, according to Rosie Salisbury, a spokeswoman for the hotel and casino.

State judges have been reducing or canceling jury pools to limit the number of people in the courthouses.

In Rhode Island, Governor Gina Raimondo asked residents to refrain from attending and organizing events of 250 people or more for the next two weeks. That includes parades, sporting events, and other large gatherings. The state is urging anyone 60 years old or older — or with health conditions — to stay away from events for the next two weeks.

But some Rhode Islanders will get a chance to help researchers understand the coronavirus. The principal of Saint Raphael Academy in Pawtucket, the private high school tied to the state’s first coronavirus cases, is asking parents to allow their children to participate in a federal study of why the virus affects various populations differently.

In the United States, just over 1,000 cases have been diagnosed and 29 people have died.

“We expect to see the number of cases, the number of deaths, and the number of affected countries climb even higher,” said WHO’s Director General Tedros Adhanom Ghebreyesus.

In Massachusetts, some 445 state residents are under quarantine, up from 249 a week ago, and 638 have completed their quarantines.

The number of cases in Massachusetts rose only slightly to 95 on Wednesday. A one-day change does not indicate any longer-term trends in the epidemic’s progress in the state.

Of the 95 Covid-19 cases, 77 were traced to a leadership conference of Biogen employees in Boston late last month. Four were related to foreign travel, and 14 remain under investigation.

The state’s Public Health Council voted Wednesday morning to grant Public Health Commissioner Monica Bharel authority to make decisions without first convening the council, including the power to order patients to isolate or quarantine, according to the State House News Service.

Meanwhile, to ensure that people with coronavirus have health insurance, the Massachusetts Health Connector, which sells plans to individuals who don’t get coverage through an employer, has opened a special enrollment period until April 25. Normally, the Connector enrolls new members only from November through January.

Separately, the CDC has promised $11.6 million to Massachusetts and $4.9 million to Rhode Island to support the Covid-19 response.

Material from the Associated Press, STAT, and the State House News Services was used in this report. Travis Andersen, Tonya Alanez, Deirdre Fernandes, Martin Finucane, Priyanka McCluskey, Dan McGowan, Jonathan Saltzman and Emily Sweeney of the Globe Staff contributed.