A surge in cases tied to international travelers led China, Hong Kong, Singapore and Taiwan to close their borders to foreigners in recent days. They also imposed measures like steep fines for leaving home and tracking bracelets to monitor quarantines.

It’s a troubling sign for the United States, Europe and other places still battling their first wave of outbreaks. Success with containment could be tenuous, and the world could remain on a kind of indefinite lockdown until a vaccine or treatment is found.

Reporter analysis: Motoko Rich, our Tokyo bureau chief, has been covering the coronavirus outbreak for months. She elaborated on some of the psychological toll that can result from being indefinitely locked down: “Being isolated for a long time, without physical and social contact with people from around the world, may have a profound effect at a societal as well as individual level.”

Here are the latest updates and maps of the pandemic. We also have a daily tracker showing the virus’s trajectory by country and U.S. state.

In other developments:

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