The growing coronavirus outbreak in the United States is revealing serious gaps in the health system’s ability to respond to a major epidemic, forcing hospitals and doctors to improvise emergency plans daily, even as they remain uncertain how bad the crisis will get.

As California announced its first coronavirus-linked fatality on Wednesday, bringing the U.S. death toll to 11, nursing homes were emerging as especially vulnerable to the virus, with more than a million residents, many of them frail. Many of the facilities have a history of struggling to contain even mundane infections.

But the gaps are spread out across the country and affect medical facilities of all types.

In Rhode Island, where two cases have been detected, doctors in protective gear were testing patients with mild symptoms in a hospital parking lot rather than allowing them to enter the emergency room. Officials said the emergency measure was being wound down Tuesday as the state’s testing capacity grows.

Officials in King County, Wash., this week said they were purchasing a motel to house patients who needed to be placed in isolation.

In rural areas of Texas and elsewhere, small hospitals do not have test kits, and central labs for testing samples are hours away. That means hospitals will be unable to conclusively determine whether they have people with covid-19 among their usual seasonal surge in influenza patients.

“There’s not anywhere near a sufficient number of kits to confirm or deny virus, or quarantine or control all these patients,’’ said John Henderson, who heads the association for Texas’s rural hospitals.

Ventilators and intensive care units, necessary to keep the most acutely ill patients alive, are largely limited to larger hospitals and academic medical centers in cities.

Front-line providers are dusting off old protocols for handling previous global health threats including severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), H1N1 and Ebola. But the coronavirus is spreading rapidly and, with mild symptoms that mimic the flu, difficult to detect.

Nationwide, worries are growing about a lack of hospital beds to quarantine and treat infected patients. Major medical centers are typically full even without a flood of coronavirus patients.

“We just don’t have the capacity in the hospitals and health systems to deal with a massive influx of patients and keep them isolated,’’ said Gerard Anderson, a professor of health policy and management at Johns Hopkins University.

Despite weeks of preparations, health planners continue to fret about shortages of masks and gowns for hospital staff, as well as lifesaving mechanical respirators for patients with severe cases of the disease.

“We need masks, we need ventilators for our medical facilities, and we need it fast,” Sen. Patty Murray (D-Wash.), whose state has experienced the largest fatal outbreak in the country, said on Tuesday.

The World Health Organization on Tuesday warned that panic buying and hoarding were creating a dangerous global shortage of protective equipment. China, where the outbreak began, has stopped exports.

Budget-conscious health systems do not maintain large volumes of reserve supplies just for the possibility of a pandemic, said William Jaquis, president of the American College of Emergency Physicians. That leaves the system vulnerable.

“We don’t necessarily have the backup readiness all the time for these issues,’’ he said. “And they do keep repeating.’’

Federal funding for emergency preparedness in health care has been in a slow, steady decline for more than 15 years.

The amount of federal funding given to state and local officials to prepare for health emergencies has been cut in half or more over the past couple of decades, according to Crystal Watson, senior scholar at the Johns Hopkins Center for Health Security.

The two key federal programs amounted to $1.4 billion in 2003. Those two programs amount to $662 million this year.

“Every administration has made cuts to these programs,” Watson said. “It’s been in a downward trend for a long time.”

Seven of the 11 deaths in the United States have been linked to the Life Care Center nursing home in Kirkland, Wash., and that has focused attention on the nation’s more than 15,000 nursing homes and 20,000 residential care facilities.

At risk at both those kinds of facilities are more than 2 million Americans.

Some facilities are prepared for the outbreak, and some are not, according to Lisa Sweet, chief clinical officer of the National Association of Health Care Assistants, a group that represents nursing aides.

“It runs the gamut — there are some good providers who are really on the ball,” said Sweet, who keeps up with reports from members at nursing homes.

At the better facilities, she said, managers have taken special steps: checking the temperatures of employees as they report for work; reminding family members and vendors to steer clear if they are not feeling well; and running special training for infection control.

At others, members have reported to Sweet, there seems to be no urgency to prepare.

“They’re not prepared at all,” Sweet said. “They are putting their residents in jeopardy.”

One of the particular challenges at nursing homes, aside from the vulnerability of residents, is that one worker, if infected, can become a “super-spreader,” said Lauren Ancel Meyers, a professor at the University of Texas at Austin who has studied infectious-disease surveillance.

Moreover, many nurse’s aides at such facilities might be reluctant to stay home if they are not feeling well, because they lack sick leave.

“The consensus [among her members] is that they don’t get sick leave,” Sweet said. “There’s a large proportion of single mothers in this group who need to put food on the table, and they’re incentivized to work when sick, unfortunately,” Sweet said.

A survey of hundreds of nursing homes published in the Journal of the American Medical Association in 2008 showed that slightly more than half lacked a plan to deal with a pandemic. Only about half had stockpiled supplies such as gloves, alcohol rub, surgical masks and antiviral medications, the study found.

The nursing homes surveyed for the study were in Nebraska and Michigan, but experts said the findings probably were representative of the nation.

Advocates of the nursing home industry said the facilities are better prepared now because of regulations in 2016 regarding emergency preparedness and infection control.

“All facilities need to have an infection-control plan in place, which includes what to do during an outbreak,” said Beth Martino, senior vice president of public affairs for the American Health Care Association. “These plans include the infection-control strategies a center has in place for surveillance of new infectious cases, who to report to and the steps to take to minimize the spread of an illness and manage the ill residents.”

A similar study of assisted-
living facilities published in 2014 found that 41 percent had
no pandemic plan in place.

Lona Mody, a professor of medicine at the University of Michigan and co-author of both studies, said that she thinks many nursing homes have improved in the 12 years since the study but that more needs to be done.

Doctors interviewed by The Washington Post said hospital staff are better trained and are closely counseled not to work if they are feeling Ill.

Federal officials estimated in 2005 that in the event of a severe pandemic, such as the 1918 flu, more than 740,000 people would require ventilators for breathing. But there are only about 200,000 ventilation machines in U.S. medical facilities and a national stockpile, according to experts.

“If it is the severe scenario, we will not have enough ventilators,” said Watson, of the Johns Hopkins Center for Health Security. “I don’t think this [novel coronavirus] is the severe scenario, but if it is, we will have to make some difficult decisions.”

Similarly, a separate analysis for Texas, published in 2017, showed that the state supply of ventilators would come up short in an extreme event.

“I don’t want to imply that covid-19 is in the severe class of pandemics — it could be anywhere from mild to severe given the uncertainty in the data,” said Meyers, who was principal investigator on the study.

But in the situation they studied, “there would have been a huge gap in the amount of ventilators in the stockpile and what we would have needed in a severe pandemic.”

The makers of ventilators said that, indeed, they have seen a dramatic rise in demand.

“We are seeing — and I suspect all the players are seeing — an increased demand for ventilators,” said Elijah A. White, president of ZOLL Resuscitation. “It’s not just China, it’s not just the United States, it’s all over the place.”

If the outbreak expands and individual states have hundreds or thousands of patients instead of just a few, regional plans must be established to coordinate care, said Christopher Greene, an emergency room doctor at the University of Alabama at Birmingham.

Severely ill patients needing to be placed on mechanical ventilators, but not all hospitals have them. Many rural hospitals in Texas, have none, for instance will have to be moved to hospitals with higher levels of care;, and that presents further challenges for ambulance operators and staff, Greene said. “This is a rapidly evolving thing. In a matter of days you can go from 60 cases to many, many more,’’ he said. Large hospitals are devising contingency plans for a growing outbreak, he said, but “we want to see that level of urgency at the federal level as well.’’

Leaders at Rhode Island Hospital in Providence have been planning for weeks for the arrival of the coronavirus. The virus appeared last week in one student and one staff member who traveled to Italy on a trip sponsored by a parochial high school in Pawtucket. As worry spread through the state, people who were sent by state public health officials to the hospital for testing were asked to remain in their cars until a doctor could go out to screen them.

“We have a physician in protective equipment go out to the car and put masks on anybody in the car, and take a history, and do a limited screening exam, and then do the testing, which in most cases is a nasal swab,’’ said John B. Murphy, president of Rhode Island Hospital and Hasbro Children’s Hospital. In the two positive cases, the results were available in four hours.

Now, Rhode Island officials are tracing contacts of all students and staff members on the trip to Italy.

Rhode Island Hospital has
70 “negative-pressure’’ patient rooms — which means airborne particles cannot escape — that can be used to isolate people. The hospital’s engineers are analyzing how to turn entire floors of the hospital into isolation wards.

The hospital has about 25 patients on ventilators on an average day. It can treat more than 100 people on ventilators in a demand surge, Murphy said. Beyond that, he said, in the worst case, the hospital would be forced to work with state officials to find outside facilities to isolate and treat patients.

Update: An earlier version of the story did not make clear that state public health officials referred people to Rhode Island Hospital for testing. They did not self-report.