There is no federal law requiring employers to provide paid, job-protected sick leave; 59 percent of small business employees have it. Ten states, 20 cities and three counties mandate it, though it would still be difficult for small employers to pay for days off for many workers at once, or to replace them.

Workers without sick leave, or without enough of it, risk spreading the disease or staying home and losing their job. (The Family and Medical Leave Act provides unpaid, job-protected leave, but only at companies with 50 or more employees.)

Three Democrats in Congress have introduced a bill to provide interest-free loans of up to $2 million to businesses affected by the outbreak. Others have proposed more expansive paid leave to protect workers and businesses. Senator Elizabeth Warren of Massachusetts released a coronavirus response plan that would, among other things, establish a federal fund to reimburse workers for lost wages if they missed work because of coronavirus symptoms.

Other lawmakers have long proposed a national approach to sick leave. The Healthy Families Act would require employers to pay for sick leave. But that bill might not work well for the coronavirus outbreak, since workers would earn sick time over the course of the year, up to 56 hours.

Eileen Appelbaum, the co-director of the left-leaning Center for Economic and Policy Research, which has studied the effects of two local sick leave mandates, said a disease like coronavirus might require a different response from what states have tried so far. “If someone gets the coronavirus, and they are out of work for two to three weeks or they are quarantined, that’s a place for the government to do something,” she said.

The National Federation of Independent Business, a business trade group that has often supported lower taxes and deregulation, is not calling for any changes to current policy. Holly Wade, the group’s director of research, said the organization opposed any mandated sick leave policies, and does not see a need for targeted loans for small business, given current low costs of borrowing.