“We’re not willing to run out of N95 masks,” Dr. Susan Ray, an infectious disease specialist at Grady Memorial Hospital in Atlanta, said in a phone interview, referring to the masks by their technical name. “That’s not O.K. at my hospital.”

At some point she may have no choice. Grady executives said on Monday that the hospital had a little more than a month’s supply of N95 masks; they did not immediately explain whether that estimate was based on normal levels of use or accounted for a possible spike in need. With global supplies already depleted from the outbreak in China and manufacturers facing an explosion of new orders as the virus spreads, some hospitals in the United States have been unable to get new shipments of N95 masks or even an estimate of when they might become available…

Protecting health care workers from the virus is essential to managing the epidemic, to ensure hospitals, urgent care centers and other facilities can handle inevitable surges in sick patients. A number of doctors and nurses around the country have already been quarantined for two weeks after patients they interacted with tested positive for the virus; health care workers in China have gotten sick and even died amid extreme shortages of masks and other protective gear.