In early January, Mei Lin, the chef and owner of Nightshade, a modern American restaurant in Los Angeles’s fashionable Arts District, read about a new virus spreading rapidly through China. “This is something so serious, it’s super contagious, and I knew it was going to affect the industry somehow if and when it came over to the States,” she said recently of her thinking at the time. Two months later, on March 15, when the city of Los Angeles issued