Live Coronavirus Updates and Coverage

President Trump tested negative for the coronavirus, his doctor said in a memo released Saturday evening. The president’s health had been a concern since he spent time at his Florida resort last weekend with a Brazilian official who was later found to have the illness.

“One week after having dinner with the Brazilian delegation at Mar-a-Lago, the president remains symptom-free,” said Dr. Sean P. Conley, Mr. Trump’s doctor, in that memo.

At a news conference earlier Saturday, Mr. Trump announced that he had been tested for the coronavirus on Friday night and was awaiting the results. Vice President Mike Pence also announced the extension of the administration’s European travel ban to the United Kingdom and Ireland.

Whether the president would be tested had been a matter of speculation since it first emerged that a member of a Brazilian delegation that visited Mar-a-Lago had tested positive. Two other people who were with the president at Mar-a-Lago have tested positive, and various members of Congress have been self-isolating after interacting with some of those same people.

Mr. Trump, wearing a “USA” baseball cap, said he decided to be tested for the coronavirus after his news conference on Friday, during which he declared a national emergency.

“People were asking, did I take the test,” he said.

Asked when he expected to have the result, Mr. Trump said, “A day, two days.”

“They send it to a lab,” he said.

It was unclear if Mr. Pence, who interacted with some of the infected Mar-a-Lago visitors, had known that the president was tested. Asked about his own status, Mr. Pence said, “I’m going to speak immediately after this news conference with the White House physician’s office,” which he said had previously advised him that neither he nor his wife needed to be tested.

The White House has begun checking the temperatures of anyone in close contact with Mr. Trump or Mr. Pence. White House staff checked the temperatures of everyone arriving at the news conference.

Reporters pressed Mr. Trump about “mixed messages,” asking about why he shook hands with a row of chief executives who attended his news conference on Friday where he announced a national emergency.

“It almost becomes a habit and you get out of that habit,” he said, noting that “getting away from shaking hands is a good thing.”

Mr. Pence said that, effective at midnight Monday night, the federal government’s European travel ban would apply to the United Kingdom and Ireland.

The House passed a sweeping relief package to assist people affected by the outbreak, after a roller-coaster day of negotiations on Friday, and it now goes to the Senate.

At the news conference, Mr. Trump signaled his approval of the measures, which he noted had bipartisan support.

“It was very nice to see it,” he said.

Spain and France announced drastic, countrywide restrictions on Saturday to contain the spread of the coronavirus.

Spain ordered all citizens to confine themselves to their homes — and to leave only to buy food, go to work, seek medical care or assist the elderly and others in need.

Officials in Spain reported 1,500 new cases, the largest daily increase in the country so far, pushing its total to 5,753. The government ordered all schools, restaurants and bars to close, extending measures that various regional authorities, including in Madrid and in Catalonia, had taken on Friday.

Also on Saturday, Spanish authorities said the wife of Prime Minister Pedro Sánchez, Begoña Gómez, had tested positive for the virus.

France announced the closing of all “non-indispensable” businesses as of midnight, including restaurants, bars, and movie theaters, after a sharp uptick in the assault from the coronavirus. French cases doubled over the last 72 hours to about 4,500. There have been 91 deaths, and 300 coronavirus patients are in critical condition — half of them under 50 years of age.

The measures in both countries follow similar moves in Italy, the hardest hit country in Europe. Italy has been locked down since early in the week, with only groceries, pharmacies and banks allowed to operate. On Saturday, the country reported 175 new deaths, with a total of 1,441, and 2,795 new cases, with the total crossing 21,000.

Officials in Louisiana, New York and Virginia reported their first deaths tied to the coronavirus on Saturday as the number of known cases nationally surged past 2,500. By evening, 49 states, plus Puerto Rico and Washington, D.C., had confirmed cases of the illness. Only West Virginia was without a diagnosis.

Nationwide, businesses, schools and public officials continued to struggle with an outbreak that has left more than 50 people dead and upended nearly all aspects of public life. More than 400 new cases have been reported in each of the last three days.

In the Omaha area, officials reported the first known instance of community spread. In Illinois, a nursing facility where a woman tested positive for the virus was placed on lockdown. And in Pittsburgh, where the first local cases were announced on Saturday, city leaders urged bars to promote social distancing by limiting the number of people they allowed inside.

Elsewhere, officials were making provisions to house and isolate large numbers of people with the virus.

The closing of schools in more than a dozen states continues to create concerns that children may miss meals and parents may not be able to stay home from work. Mayor Bill de Blasio, under increasing pressure to close New York City schools, has refused to cancel classes, maintaining that the schools are a lifeline for the city’s most vulnerable.

After Los Angeles Unified School District announced it was closing, school officials said that they would open 40 family resource centers to provide child care and meals to students whose parents cannot get out of work. North Carolina, on Saturday, was the latest state to close its public schools.

An Italian couple tested positive for the coronavirus in San Juan, Puerto Rico late on Friday, five days after they disembarked a cruise ship heading across the Atlantic.

Costa Cruises, an Italian subsidiary of Miami-based Carnival Corp., says the ship, the Costa Luminosa is now heading to Marseilles, France.

The Costa Luminosa set sail on March 5 from Fort Lauderdale, Fla., for a trans-Atlantic voyage. The ship called for an ambulance when it docked in San Juan on Sunday, March 8.

Puerto Rican doctors suspected that the woman, 68, had the coronavirus and hospitalized her. Her husband, 70, was asymptomatic. By the time Puerto Rico announced the hospitalization, hundreds of passengers had spent the day mingling in colonial Old San Juan, and the ship had left port.

It took five more days to confirm the cases. The island had no tests, so samples were taken from the couple and sent to the Centers for Disease Control and Prevention in Atlanta.

Gov. Wanda Vázquez of Puerto Rico called the delay “unacceptable.”

All the while, the Costa Luminosa has been at sea, passengers circulating freely. Shows have been canceled, but the gym, pool and Jacuzzi remain open. Only on Saturday did the crew rework the lunch buffet to serve passengers directly, said Kathryn Bitner, a 66-year-old passenger from San Diego, Calif.

“No one I know of has been tested in our ship,” Ms. Bitner said in a WhatsApp message.

Costa Cruises said that the ship was not in quarantine, but that the “sanitary protocol” on board had been increased and close contacts of the passengers who tested positive had been isolated in their cabins. Costa Cruises also said that it was instituting a daily temperature check for crew and passengers.

The ship’s final destination is unclear. Passengers were first told that they would get off in the Canary Islands, off West Africa. Then Málaga, Spain. But it now appears that Spain is suspending new cruise ship arrivals, and passengers got a letter from the cruise ship company Friday night telling them that the latest plan is to disembark in Marseille, France, on March 19.

Georgia is pushing back its primary, but other states still plan to vote on Tuesday.

Georgia will postpone its March 24 presidential primary for nearly two months, officials said Saturday, becoming the second state to delay voting in response to the coronavirus outbreak.

The move comes as officials in the next four states scheduled to vote in the primary — Arizona, Florida, Illinois and Ohio — have all indicated they intend to hold their elections on Tuesday as planned, issuing a joint statement on Friday expressing confidence that ballots can be safely cast.

Louisiana on Friday became the first state to postpone its primary, announcing that the April 4 election would be delayed by more than two months.

The Georgia primary will now be held May 19. The sudden decision by Georgia, announced Saturday night, comes as the viral outbreak has upended the presidential campaigns and people worry about gatherings and places where they might become infected.

Israel’s prime minister, Benjamin Netanyahu, said on Saturday that digital and technological means would be employed to track citizens known to have contracted the virus, an extraordinary measure he said was drawn from Israel’s war on terrorism.

In a televised address on Saturday night, he said that Israel was “at war” against an “invisible enemy.”

Acknowledging that the surveillance would impinge on personal privacy, Mr. Netanyahu said he had sought and received permission from the Justice Ministry.

As the country’s caseload rose to nearly 200, the government mandated the closure of all leisure venues starting on Sunday, including cafes, restaurants, gyms and cultural institutions. Public gatherings are to be limited to 10 people, public transportation will be scaled down and workers have been told to work from home if possible.

Many other countries increased restrictions:

• The British government appears nearer to banning mass gatherings, something it had so far resisted. The number of deaths from the coronavirus nearly doubled on Saturday to 21 and the number of cases surged by more than 300 to 1,140.

• The Afghan government closed all schools and universities for a month and asked people to avoid weddings and engagements — events that usually draw thousands. The war-torn country, which shares a porous border with Iran, reported its 11th case on Saturday. But testing is severely limited, so it’s hard to gauge how widespread the outbreak is.

• Indonesia reported a sharp increase that raised its number of cases to 96, with 5 deaths. The governor of Jakarta announced that schools in the capital would close for two weeks. The transportation minister, Budi Karya Sumadi, has tested positive.

• Singapore has closed all its 70 mosques for five days to disinfect them, after the spread of the virus in at least three countries — Malaysia, Brunei and Singapore — was connected to a gathering of 16,000 people at a mosque near the Malaysian capital, Kuala Lumpur. Four cases in Singapore have been linked to that gathering, which was attended by more than 90 Singaporeans.

• Prime Minister Jacinda Ardern of New Zealand announced that everyone arriving in the country after Sunday night will have to isolate themselves for 14 days. The measure applies to citizens as well as foreigners.

• Rwanda reported its first case, an Indian national who arrived on March 8 from Mumbai. The man sought medical help on March 13, the health ministry said.

• Namibia, in southern Africa, reported its first two cases: a Spanish couple who arrived there on Wednesday. They are both under quarantine, Health Minister Kalumbi Shangula said on Saturday.

• The president of Colombia ordered the border with Venezuela closed.

• Guatemala will bar citizens from the United States and Canada, and recent visitors to those two countries may be asked to self-quarantine for seven days, officials said. Guatemala confirmed its first coronavirus case on Friday: a 27-year-old man who had traveled from Spain to Guatemala via Colombia and El Salvador.

Despite being pressed repeatedly at the White House news conference on Saturday, Mr. Pence did not share substantive new details about Mr. Trump’s earlier claim that Google was developing a website to help people decide whether a test for the coronavirus was warranted and where they could get one.

The confusion started when Mr. Trump thanked Google on Friday for developing the website, which he said would be “very quickly done.”

But later Friday, Carolyn Wang, a spokeswoman for Verily, a subsidiary of Google’s parent company, said that the website was meant to help health care workers triage people for virus screening, that it would be available by Monday and that it would be limited to testing sites in the Bay Area. If the pilot goes well, Verily said, it plans to deploy the project nationwide but there is no timetable for a national rollout.

Ms. Wang said that Mr. Trump’s statement prompted the company to plan to make the site available to the public.

On Saturday, Mr. Pence said the government was working “24/7” on the website and more details would be released at 5 p.m. on Sunday.

“What Google said was that they’re planning to launch a website this coming Monday, March 16, that will enable individuals to do a risk assessment and be scheduled for testing at pilot test, sites in the Bay Area with the goal of expanding to other locations” Mr. Pence said. “And we’re very grateful for that.”

Italians cope with quarantine by singing on their balconies.

Italy is locked down, in the face of what is so far Europe’s most severe coronavirus outbreak. Italians, however, are still getting their voices heard.

At precisely noon on Saturday, millions of Italians, from Piedmont to Sicily, leaned out of windows or stood on their balconies to applaud the health care workers in hospitals and other front-line medical staff who have been working round the clock to care for coronavirus patients.

As church bells normally drowned out by traffic pealed in the surreal silence that defines Italy since Wednesday’s lockdown, applause filled streets, piazzas and even country roads, after messages went viral on social media calling Italians to put their hands together.

There was a similar response to another online appeal Friday evening, asking Italians to sing the national anthem — or play it on a musical instrument — at exactly 6 p.m. The socially distant flash mob swept social media.

Naturally, not everyone is blessed with a voice like Pavarotti. Some Italians preferred banging on pots and calling out, “We will make it.”

It’s unclear who began the musical interlude, but in the land that gave the world opera, it’s clearly not meant to be a cacophonous mess, and a program for more songs is spreading online. At 6 p.m. on Saturday, Italians will sing “Azzurro,” a 1968 hit by the singer Adriano Celentano, and on Sunday, “Ma il cielo è sempre più blu,” by Nino Gaetano, which topped the charts in 1975.

As thousands of Americans flee from Europe and other centers of the coronavirus outbreak, many travelers are reporting no health screenings upon departure and few impediments at U.S. airports.

Since January, officers from Customs and Border Protection have been on heightened alert for travelers who might spread the virus. The Department of Homeland Security has told employees to look for physical symptoms, search through travel documents and review a federal tracking database.

But travelers, including some who say they showed visible signs of illness, say screening has been lax. Members of Congress this week grilled senior Homeland Security officials over what some described as a porous screening process.

Even top officials at the department acknowledge that fully sealing the United States from the virus is impossible.

“We are trying to reduce and delay the biggest peak in the virus wave hitting on the United States of America,” said Kenneth T. Cuccinelli II, the acting deputy secretary of Homeland Security. “And all of these steps reduce and delay. They do not stop the virus.”

Amid a surge of false information on the new coronavirus, Apple said on Saturday that it will only allow virus-related apps from recognized health authorities — like government agencies, health nonprofits and medical institutions — in its app store.

The company also said that it would prohibit virus-themed entertainment or game apps.

Other big tech companies like Facebook, YouTube and Twitter have said they were working with authorities like the World Health Organization to combat conspiracy theories and misleading medical advice about the virus and to point people to credible sources of information on it.

Apple’s announcement came one day after it closed most of its stores worldwide, becoming one of the first major retailers to take such drastic measures.

The company’s chief executive, Timothy D. Cook, said that Apple would shutter all stores until March 27, excluding those in mainland China — where infections have significantly declined recently — and in Hong Kong and Taiwan.

“The most effective way to minimize risk of the virus’s transmission is to reduce density and maximize social distance,” Mr. Cook said in a statement posted to the company’s website.

Many firms around the world are contemplating similar measures. Patagonia, the outdoor-clothing retailer, said on Friday that it would shut its stores until late March. Starbucks has said it would consider closing stores temporarily as a “last resort.”

The virus has already taken a toll on many businesses, disrupting supply chains and hurting demand in critical markets.

Apple recently reopened all of its 42 stores in China, after closing them for more than a month. But the company has struggled to ramp up production of smartphones amid delays at its factories in China.

Your home dynamics have changed. Here’s how to manage the shift.

More schools are closing, more companies are asking employees to work remotely. Here are some tips to help you work from home more efficiently, and balance home schooling for your children.

And here is more coverage on how the coronavirus affects your day-to-day life here.

Reporting was contributed by Isabel Kershner, Adam Nossiter, Nicholas Bogel-Burroughs, Mujib Mashal, Najim Rahim, Andrew Kramer, Maria Varenikova, Helene Cooper, Hannah Beech, Elisabetta Povoledo, Marc Santora, Johanna Berendt, Choe Sang-Hun, Stephen Castle, Richard C. Paddock, Muktita Suhartono, Elian Peltier, Peter Robins, Keith Bradsher, Damien Cave, Emily Cochrane, Javier Hernandez, Zolan Kanno-Youngs, John Schwartz, Liz Alderman, Mihir Zaveri, Patricia Mazzei, Frances Robles and Annie Karni.