By the time the global coronavirus outbreak arrived in New York this week, the city was armed with hundreds of hospital beds, a growing stockpile of diagnostic testing kits and enough disinfectant to wipe down the entire subway system. Mayor Bill de Blasio’s vaunted health department had honed its response to the potential crisis in recent years by tamping down swine flu, Ebola and other epidemics before they could paralyse the nation’s financial capital and most crowded metropolis. But even though New York City’s preparedness is evident, inevitable points of strain are also beginning to show. The mayor has said he needs the federal government to send hundreds of thousands more disposable protective masks for nurses and other health workers. Some hospitals are already relaxing safety protocols, urging workers to reuse single-use masks for an entire shift where possible. If the epidemic were to turn dire, experts say other resources could become scarce, such as hospital beds, mechanical ventilators and even medical staff. “New York City has one of the greatest health departments in the world,” said Tom Frieden, an infectious disease physician who was a former New York City health commissioner. “But make no mistake, any city in the world would be challenged with an outbreak of the size or scale that Wuhan has had to deal with.” More than 2,000 people have died in Wuhan, the Chinese city at the centre of the outbreak of the novel virus strain, which causes a sometimes deadly respiratory illness called COVID-19. New York City, where 8 million people live in close proximity with one another, is the kind of place where such contagions thrive. So far only four people have tested positive for COVID-19 in New York City. Outside the city, some local governments are already under stress. The county in Washington where all but one of the state’s 10 deaths have occurred is working to buy a motel to house and isolate patients. Los Angeles County on Wednesday declared a health emergency to help cope with the virus. Across the U.S. hospitals are generally running at or near full capacity, according to a recent research paper by scholars at the Johns Hopkins Center for Health Security, which noted that there are about 46,500 intensive care unit beds nationwide. In a moderate outbreak, an estimated 200,000 U.S. patients would need ICU care, according to the paper. If the virus spread along the lines of the 1918 Spanish flu, which killed half a million in the United States, it would become much more likely that capacity would fall short, according to Richard Waldhorn, a co-author of the paper. “I don’t think any place is completely prepared for the scope of the challenge that could be if this turns into a severe pandemic,” Waldhorn said. WASH YOUR HANDS In New York City, Reuters interviewed more than a dozen hospital doctors, nurses, and current and former officials of a health department with a strong reputation for dealing with such crises. Many of them said the city had a right to be cautiously confident about its preparations at this stage. New York is flooded with multilingual advisories reminding the public of the importance of thorough hand-washing. The city has accelerated cleaning schedules for its schools, and the state is disinfecting every subway train every 72 hours. Even so, every outbreak can take unexpected turns, and no one can predict how severe it will prove to be. One point of vulnerability is a potential shortage of the so-called N95 respirators that snugly fit around the nose and mouth, protecting nurses from getting infected themselves. Some hospitals have begun to keep their dwindling stashes under lock and key and have advised nurses who would normally replace their single-use masks between each patient to see if they can reuse the same one through an entire shift. “We actually have them on lockdown,” said Dr. Jennifer Lighter, an epidemiologist at NYU Langone’s network of hospitals and clinics. She said their supply has been disrupted because the masks NYU use are made in China’s Hubei Province, the centre of the coronavirus outbreak, which has been under strict quarantine. Under an emergency conservation plan, NYU is telling staff to reuse masks when treating multiple patients for certain low-risk medical procedures, so long as the masks do not get wet or damaged, Lighter said. Mayor de Blasio has said there is no current shortage of N95 respirators but said the city would need help from the federal government in a more severe crisis. To that end, the U.S. Department of Health and Human Services said this week it was purchasing 500 million N95 respirators over the next 18 months to build the nation’s stockpile. HOSPITAL BEDS Some aspects of the city’s preparedness remain unknown. For example, health officials were unable to answer questions this week about how many mechanical ventilators the city has available for especially sick COVID-19 patients who need help breathing. But the city says it has already lined up about 1,200 hospital beds for COVID-19 patients. “We have immense capacity,” de Blasio said this week. During the 2009 pandemic of the H1N1 influenza strain, commonly known as swine flu, a little more than 900 people were hospitalized with the illness in the city between April and August. Even in the busiest single week during that outbreak, which killed 45 New Yorkers, fewer than 300 patients were hospitalized, according to city data. “Had it been more severe, some problems may have been revealed,” said Isaac Weisfuse, a deputy commissioner at the city’s health department at the time. “These issues don’t get kind of revealed until you are stressed.”