Dr Carlos Del Rio likens it to an incoming hurricane: people board up their windows and stock up on supplies, but they are only able to tell whether their efforts were successful after the storm has passed.

"To say we're prepared, we're not prepared - I think we'll only know that at the end of the episode," he said when asked the question that is on many people's minds this week: "Is the United States prepared to handle the novel coronavirus?"

"Preparedness is tricky," added Del Rio, a professor of medicine and global health at Emory University in Atlanta, in a phone interview. "Because you don't know how prepared you are until you know what you're facing.

"Having said that, at this point in time, we look like we are not prepared."

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Part of the reason why is a lack of medical testing across the US. Without testing, it is impossible to truly measure just how widespread the virus is, or how to respond effectively.

The coronavirus, which causes COVID-19 disease, originated in China, where it has killed nearly 3,000 people, and spread to dozens of countries. People with COVID-19 typically have a fever and a cough, shortness of breath and other respiratory problems. The virus spreads through person-to-person contact, such as when an infected person sneezes or coughs and those droplets are inhaled by someone else.

On February 28, the World Health Organization said the global risk of the spread and impact of the coronavirus was "very high" - the highest level of alarm.

"We have been dealing with this virus for two months and I think this is a reality check for every government on the planet - wake up, get ready," said Dr Mike Ryan, executive director of WHO's emergencies programme. "You have a duty to your citizens. You have a duty to the world to be ready."

Testing delays

Most public health experts in the US say delays in testing for the coronavirus remains the biggest obstacle for dealing with its potential spread.

The country remains "behind much of the rest of the world" on testing, said Dr William Schaffner, professor of preventive medicine and infectious diseases at the Vanderbilt University School of Medicine in Nashville.

That is because, the Centers for Disease Control and Prevention (CDC), the federal agency responsible for public health, chose to create its own testing kit instead of using one recommended by the WHO and it took longer than anticipated, Schaffner said.

Initially, doctors had to contact their state health department and answer a questionnaire to see if their patient met strict criteria to be tested. That test would then be sent from a state laboratory to the CDC in Atlanta, which at the time was the only place in the US doing such testing. "It was very cumbersome. It took a lot of time and it was just terribly inefficient," Schaffner said.

Once the CDC test was ready, it was sent out to state laboratories to administer - but the kits turned out to be flawed. Schaffner said the hope is that state facilities will be able to carry out effective tests within the next week.

That will be key to knowing just how widespread COVID-19 is across the country. "We don't know yet in the United States whether the coronavirus is widely distributed or whether it is just present in certain small spots," he said.

State and local health agencies then will need to coordinate and put out the necessary directives to respond, depending on the scope of the outbreak. "Are we going to quarantine people? Are we going to ask people not to go out of their homes? Are we going to ask them not to go to sporting events and religious services and the like?" said Schaffner, about what public health experts will be considering.

A Metropolitan Transportation Authority worker sanitises surfaces at the Coney Island Yard in the Brooklyn borough of New York City; the MTA is stepping up efforts to sanitise cars and stations as fears mount over the coronavirus [Kevin Hagen/AP Photo]

Social factors

Krys Johnson, a professor of epidemiology at Temple University in Philadelphia, said a cluster of cases in Washington state raises questions about whether the criteria to decide who gets tested needs to be widened.

Johnson said only people linked to a confirmed case of the coronavirus, or to what is known as a "presumptive positive" - someone who is believed to have the virus - can be tested, too. "The definition for testing hasn't kind of kept up with the knowing that there is likely community spread in Washington state, so that's an issue with preparedness," she told Al Jazeera.

Social factors may also deter people from getting tested for the coronavirus, including the high cost of medical care and lack of comprehensive health insurance.

Johnson pointed to a recent case in Florida, where a man who had just returned from a work trip to China and developed flu-like symptoms went to a hospital believing he may have contracted the coronavirus. His tests came back negative - but he said his insurance company charged him $3,270 for the hospital visit.

In New York state, Governor Andrew Cuomo ordered state insurers to waive the costs of coronavirus testing, including emergency room visits. "These measures will break down any barriers that could prevent New Yorkers from getting tested," Cuomo said.

Also, US federal law does not require employers to grant paid sick leave, which may affect people's ability to stay home when they are sick, as the CDC recommends. Seventy-six percent of all American workers had access to it in 2019, the US Department of Labor data shows, but that figure dropped to 31 percent for workers whose incomes were in the bottom 10 percent.

"These conditions create a near-guarantee that workers will defy public health warnings and trudge into their workplaces, regardless of symptoms," Karen Scott, a PhD student at the Institute for Work and Employment Research at MIT, wrote last month.

"In this way, a manageable health crisis can spiral out of control."

Cameron Nightingale adjusts his mask and gloves, a precaution to protect himself from coronavirus, while walking by cable car in San Francisco, California [Josh Edelson/ AFP]

Protecting workers

Experts also warn that being unprepared could lead to a shortage of healthcare workers, such as nurses, who may be forced to self-quarantine after being exposed to the virus on the job. That recently happened in California when a COVID-19 patient sought care at the UC-Davis Medical Center in Sacramento.

At least 36 registered nurses and 88 other healthcare workers were sent home to self-quarantine after that single patient was admitted, said National Nurses United, a nurses' union that represents more than 150,000 members across the US. The case, the union said, demonstrated "a system failure".

In a preliminary survey of more than 1,000 nurses in California, NNU also said that nearly half (47 percent) of the respondents said they did not know if there was a plan in place to isolate a patient believed to have COVID-19 at their medical facility.

Ensuring that healthcare workers have the equipment and supplies they need to safely do their jobs is also a growing concern, with the US surgeon general recently urging Americans to "STOP BUYING MASKS!" in a widely circulated tweet.

"They are NOT effective in preventing general public from catching #Coronavirus, but if healthcare providers can't get them to care for sick patients, it puts them and our communities at risk!" said Dr Jerome Adams.

Dr Del Rio questioned whether an already strained US healthcare system would be able to handle an influx of coronavirus patients. "We manage healthcare at capacity and ... there's very little empty beds," he told Al Jazeera. "If you were to have a pandemic, what are you going to do with people?"

He also said that while the CDC regulates public health at the federal level, many decisions around COVID-19 will be taken on a state-by-state basis. That could be "a barrier to responding effectively", he said, because states with robust public healthcare systems may fare better than those with weaker ones.

A sign tells customers that all N95 protective masks are sold out at Marin Ace Hardware on March 2, 2020, in San Rafael, California [File: Justin Sullivan/Getty Images/AFP]

Best practices

Johnson at Temple University urged people to listen to public health recommendations and call their primary care physician, urgent care or emergency health department if they believe they may have the coronavirus.

"Call your physician before you go somewhere so you can limit the number of people who are infected," she said. "They would much rather bring you in a back door than have you coughing in a waiting room."

If you are not interested in getting tested but feel sick, she said, you could stay home and use standard flu remedies - cough syrup, fever-reducing medication and getting lots of liquids and rest - until you get better. "For most people, they're not going to need medical intervention," Johnson said.

You should do what you can to prevent getting sick, though. That includes washing your hands properly, using hand sanitiser, coughing into your arm instead of into the air, and minimising the number of times you touch your face, especially on public transport.

"Overall most people are not going to have severe complications from this," she said, adding, however, that "people who are immuno-compromised, or elderly and more at risk ... [need to] know that they do need to be acting out of an abundance of caution."