Ms. Suen endured Hong Kong’s earlier problems, like the outbreak 17 years ago of SARS, which killed almost 300 people and briefly knocked the territory’s economy off track. This time feels different, she said, as Hong Kong endures political, economic and social crises all at once.

“During SARS,” she said, “people were still working together.”

The new coronavirus, which has killed hundreds and sickened thousands in mainland China, has been much less prevalent in Hong Kong. One person has died and at least 26 have been infected, mostly while traveling in the mainland. Its hospitals are respected around the world, and its grocery stores remain largely well stocked.

The world is not drawing a distinction, however, in part because the city has tightened but not fully closed the border with the mainland. As a result, people in this global city are feeling increasingly cut off.

The multinational companies that helped make this city global are restricting travel there. Some are advising or requiring returning employees to quarantine themselves. And getting to Hong Kong is becoming increasingly difficult: Virgin Australia on Thursday joined United Airlines and American Airlines in cutting service.