LONDON (NYT NEWS SERVICE).- On Broadway, theater doors are shut. In Milan, the Teatro alla Scala opera house is silent. In Paris, theaters including the storied Comédie-Française announced Friday they were closing down temporarily, too.

Across the United States and across Europe, theaters and other cultural venues have drawn the curtains as authorities try to halt the spread of the coronavirus.

But Friday afternoon, inside the National Theater in London, the show was going on. Dozens of people milled around in the foyer of the concrete building on the south bank of the river Thames, many of them with a drink in hand. They were about to go in and see “The Seven Streams of the River Ota,” Robert Lepage’s seven-hour saga about the repercussions of the atomic bombing of Hiroshima.

Tasha Kitcher, 22, said she wasn’t worried about sitting next to a stranger for such a long time. “We’re British,” she said, “so it’s, like, whatever.”

Barbara Shep, 65, was a little more concerned. She would ask to move if someone next to her coughed or sneezed, she said. “But I think you’ve got to carry on and just try and be as careful as you can,” she said.

“I’m quite glad it’s seven hours,” said Alastair Knights, 30. “I think I’d happily stay in there for double that, if it meant that I wasn’t just looking at my phone going, ‘Argh.’”

On Friday, Britain’s approach to containing the coronavirus seemed out of step with other European countries. France, Denmark, and Austria, for example, have restricted indoor gatherings to fewer than 100 people. But the government here has not placed any restrictions on events. At a news conference Thursday, Prime Minister Boris Johnson simply advised anyone showing symptoms of the virus to self-isolate for seven days.

Patrick Vallance, the government’s chief scientific adviser, explained the government’s reasoning to BBC radio on Friday. “The most likely place you’re going get an infection from is from a family member, a friend, somebody very close, in a small space,” he said.

There were 798 confirmed cases in Britain on Friday morning, although on Thursday, health authorities estimated that between 5,000 and 10,000 people in the country were infected.

It’s not just theaters that are open: Most of London’s museums were open Friday, too, including Tate Modern, despite an employee there having tested positive for the coronavirus.

Some event organizers in Britain have decided to take their own actions, canceling or postponing tours and festivals. On Friday, the Premier League, Britain’s top soccer competition, announced it was suspending matches.

But cultural venues, most of which are not insured against pandemics, were waiting for instructions from the government.

In a statement on Friday, the Society of London Theater, a trade body, said, “Following the latest government advice, theaters continue to stay open as part of the scientific rationale for managing the coronavirus outbreak.”

“In uncertain and anxious times, theater can provide a much-needed boost and escape,” it added.

Over 15.3 million people saw plays and musicals in London in 2019 — more than 1 million more than on Broadway — according to the society.

The society had issued guidance to its members to limit contact between staff and audience members, such as at stage doors. Theaters should also deep clean venues regularly, it added. Actors were told to sign autographs with their own pens.

On Wednesday, Daily Mail Online, the website of The Daily Mail newspaper, published a story with the headline: “The best time to snap up theater tickets!”

Tickets for popular shows in London’s West End, including “Hamilton” and “Wicked,” were now available for just 15 pounds, about $18, “as tourists cancel bookings amid the coronavirus outbreak,” the website said.

Five London theater owners turned down or did not respond to interview requests to discuss coronavirus for this article. Philip Bernays, chief executive of the Theater Royal, Newcastle Upon Tyne, in northeastern England, said that he understood why the government had not ordered closures. “It’s an immensely complicated situation,” he said. “It’s about balancing safety and the economy.”

Some impact of the coronavirus could be seen in London’s theaters on Friday. During a packed performance of “Hamilton” at the Victoria Palace Theater, a few attendees wore face masks. At one point in the show, Gavin Spokes, playing King George, cleared his throat and made a look of mock virus-related concern at the audience. He got a huge laugh.

And at Shakespeare’s Globe theater, a cleaner was rubbing down handrails with Safe Zone Plus, a disinfectant that kills viruses, as school groups and tourists waited to see a performance of “The Taming of The Shrew.”

A few groups had canceled bookings, but some shows including Saturday evening’s performance of “Macbeth” were sold out, said a spokeswoman for Shakespeare’s Globe.

Inside, Georgina Frylink, 37, a nanny on a trip from Edinburgh, was sitting in the mezzanine with a friend, nursing a drink and waiting for the show to begin. She was the only person in the audience who looked worried. “My boss is a doctor, and she advised against going to large gatherings,” she said.

“I’m a bit nervous,” she said, when asked how she would feel if someone coughed, “but it’s a little bit too late to do anything about it now.”

The play soon began. Five minutes in, a woman about 30 feet from Frylink started to cough, quickly raising her elbow to her mouth (as advised by health authorities). The woman unwrapped a sweet, but it didn’t seem to help. She kept hacking into her arm.

But no one in the audience turned around to look. Even Frylink didn’t. They were absorbed by the action onstage. Then everyone laughed at a joke.

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