The cautions suggested by the Centers for Disease Control and Prevention for those who contract the virus but don’t need to be hospitalized are the sort of measures that might be workable in Denver or Houston but seem less so in New York, where the average size of an apartment built during the past 20 years is 866 square feet. They include the directive to “stay in a specific room and away from other people in your home” and to use “a separate bathroom.”

The line between an appropriate response and an excessive one is not terribly clear. This week I encountered a friend who had transitioned to Clorox wipes as a means of disinfectant because “this was not a time for Seventh Generation.” Someone else described herself as only mildly concerned about the spread of coronavirus but, nevertheless, she was planning to stock up on canned goods.

At the same time, some companies have told employees who have recently been to Italy, where 400 cases of infection had been identified by Thursday, to remain at home. Members of New York’s fashion industry are at particular risk because so many have been in Milan for the Fall 2020 shows held this month. Recently, Hearst Magazines instructed editors and others who had returned home from Italy, Iran and parts of Asia during the past 30 days to work remotely for two weeks.

Food markets and restaurants in Chinatown are bearing the greatest burden of collective fears, even though no cases of Covid-19 have been identified in New York as of this writing. The Chinatown Partnership has estimated a 40 to 60 percent drop in sales for these businesses since the coronavirus first emerged in Wuhan, China.

That the safety of meat and fish is more strictly regulated in this country, Tiffany Chau, the Partnership’s policy director told me, has had little effect on shopping and eating habits. Chinatown’s retail model is built on low prices to attract a high volume of sales. Now that model is imperiled. A few weeks ago, a campaign called “Show Some Love in Chinatown’’ was devised in an attempt to lure people back.

In the coming weeks, city officials will remind New Yorkers to wash their hands, cough into their elbows and wed themselves to bottles of Purell, but they are unlikely to assume any culpability for what could now or someday be the most serious rupture to the safe management of a major outbreak of infectious disease.

Since 2004, 17 hospitals have closed in New York resulting in a net loss of beds and the chance that if the city were beset by an epidemic, it might not be able to accommodate the needs of everyone who got sick.