They have been hampered not only by a staggering drop in customers, but also by the difficulty of procuring supplies and getting workers back to the city from holiday travels that were supposed to have ended nearly a month ago.

The industry survey estimated that the cost to the restaurant and catering industry across the country had already reached $85 billion. It called the epidemic the industry’s Waterloo, after the final defeat of Napoleon Bonaparte in 1815, and warned that enterprises with insufficient cash flow or popularity would likely never reopen.

“Yes,” said Ms. Du, “there will be a lot that can’t survive.”

Pang Mei’s Noodle Shop opened in 2015 in one of Beijing’s distinctive alleyways known as hutongs, offering pungent, chili-soaked noodles in the style of Chongqing, the city in central China. It is an offshoot of a chain from Chongqing owned by a cousin of Ms. Du’s husband, Yuan Jie, and has won a devoted following. (A year after it opened, Eater included it as one of 38 “essential Beijing restaurants.”)

In the last days before the Lunar New Year holiday in January, Ms. Du recalled in an interview, she felt anxious as she worked the register. The first worrisome reports of the coronavirus were emanating from Wuhan, she said, referring to the city now recognized as the center of the outbreak. The regular crowd was “very much at ease, happily slurping noodles.”

“People did not really take it seriously,” Ms. Du, 34, said. That was five weeks ago.

Like most small shops and restaurants in Beijing, the couple planned to close for the holiday and reopen on Feb. 6. But the epidemic, and the government’s efforts to contain it, had ripple effects that disrupted the restaurant’s supply of spices and peppers from Chongqing.

The ones in Beijing are “not as flavorful,” Ms. Du explained. In any case, many of the city’s markets also closed. “We didn’t even have the very basic seasonings.”