The Center for Disease Control and Prevention (CDC) reportedly took four days to test a person with the first confirmed case of coronavirus where the origin of the disease is unknown because they 'didn't fit the criteria'.
Officials said the patient is being treated at UC Davis Medical Center in Sacramento.
The patient, who is a resident of Solano County, was admitted into the hospital on February 19.
But questions are now being asked over the CDC's handling of the case after an email from medical center officials to employees revealed that the CDC took four days to test the patient for the deadly disease despite requests from staff at the center.
The leaked memo also suggested medical center staff may have been unnecessarily put at risk after some have now been told to go into isolation and watch for symptoms.
According to the email, the CDC didn't test the patient, who has not been identified, for coronavirus until February 23.
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The Center for Disease Control and Prevention (CDC) reportedly took four days to test a person with the first confirmed case of coronavirus where the origin of the disease is unknown because they 'didn't fit the criteria'. This image shows residents of San Francisco, California, on Wednesday
Questions are being asked over the CDC's handling of the case after an email from medical center officials to employees revealed that the CDC took four days to test the patient for the deadly disease despite requests from staff at the center. People wear masks in San Francisco, California, on Wednesday
The CDC tested the patient, who has not been identified, for coronavirus on February 23. The test results came back on Wednesday. This illustration shows a transmission electron microscopic image of an isolate from the first US case of COVID-19
The patient, who is a resident of Solano County, is being treated at UC Davis Medical Center (pictured) in Sacramento
According to the internal memo from UC Davis Medical Center obtained by CBS13, the patient was transferred from another Northern California hospital on February 19 and was already intubated and on a ventilator.
However, despite requests from medical center officials for the CDC to test the unknown individual, the patient was only tested for coronavirus on Sunday - four days after they were admitted to the hospital - because 'the patient did not fit the existing CDC criteria for COVID-19', the email said.
The email from the David Lubarsky, vice-chancellor of human health services, and Brad Simmons, interim CEO of UC Davis Medical Center, to the center employees confirmed that the test had come back positive Wednesday.
'Upon admission, our team asked public health officials if this case could be COVID-19. We requested COVID-19 testing by the CDC, since neither Sacramento County nor (the California Department of Public Health) is doing testing for coronavirus at this time. Since the patient did not fit the existing CDC criteria for COVID-19, a test was not immediately administered,' said the email, which added that, 'UC Davis Health does not control the testing process'.
The hospital has been treating one other confirmed case of coronavirus, though the other patient contracted the disease through travel after returning to the US from China on February 2.
'This is not the first COVID-19 patient we have treated, and because of the precautions we have had in place since this patient's arrival, we believe there has been minimal potential for exposure here at UC Davis Medical Center,' the email said.
However, the email said some staff members had been warned to go into isolation and to stay vigilant to any developing symptoms.
'A small number of medical center employees have been asked to stay home and monitor their temperatures,' the email said.
The CDC confirmed that the person had not recently returned from a foreign country, and had not been in contact with another confirmed case.
The news suggests that fears of the disease spreading locally in the US could now be a reality - while President Donald Trump continued to tell the public that the risk to Americans is 'low'.
Coronavirus cases in the US have now risen to 60, including 42 passengers who were aboard the Diamond Princess cruise ship, three people repatriated from China and 15 on US soil
More than 82,000 cases of coronavirus have been confirmed globally and more than 2,800 deaths have been reported
Trump announced in a press conference Wednesday night that the US was 'very ready' to tackle the disease as he also handed Vice-President Mike Pence the task of leading the nation's response to the disease.
The US has taken extreme precautions to ensure that anyone traveling back from China has been quarantined in order to limit the spread of the disease.
News of the first case where a patient has no known connection to travel abroad or to another known case has raised concerns over how the disease could spread across America.
A statement from CDC confirmed the first possible instance of 'community spread' in the US Wednesday evening.
'At this time, the patient's exposure is unknown. It's possible this could be an instance of community spread of COVID-19, which would be the first time this has happened in the United States. Community spread means spread of an illness for which the source of infection is unknown,' the statement said.
The CDC did not rule out that the patient may have been in contact with an infected individual who is yet to be diagnosed or linked to the individual.
'It's also possible, however, that the patient may have been exposed to a returned traveler who was infected,' the statement said.
'This case was detected through the US public health system — picked up by astute clinicians. This brings the total number of COVID-19 cases in the United States to 15.'
Officials said they will be tracing the infected individual's contacts to see how they may have been infected and if any other individuals may be at risk.
A chief doctor at the medical center refuted Trump's claims that the US is 'ready' for an outbreak and sent a stark warning that the local Californian community is not prepared.
'We don't have that much data, so we don't really know how many symptomatic, or asymptomatic patients there are in the community right now. The testing is very limited. We would like to have more widespread testing so we know where this virus is — who's sick and who is at risk,' Dr Dean Blumberg, the Chief of Pediatric Infectious Diseases at the UC Davis Children's Hospital, told CBS Sacramento.
Blumberg said that if community transmission is confirmed, there could be many more cases out there.
'We only have this one confirmed case of community transmission, but it suggests that we don't know where they got it from, so the person who exposed them, so there's probably other cases in the community that we don't know about,' Blumberg said.
The UC Davis Medical Center has not responded to a request for comment from DailyMail.com.
School closure amid fears of coronavirus
Meanwhile, school administrations in Washington state have been taking precautions of their own.
In a letter to families, officials announced that Bothell High School would be closed on Thursday.
According to Michelle Reid, the superintended of the Northshore School District, officials have gained more insight into 'the number of families in our community that traveled internationally during our time off'.
Reid said a Bothell High School staff member returned to work on Monday after a week of international travel.
'They reported that a family member who was traveling with them became sick on Tuesday, and was taken to the hospital, and is currently being treated, monitored and quarantined. The staff member is also quarantined at home for 14 days.
'At this time, there is no confirmation that the family member's illness is connected to the coronavirus outbreak, but out of an abundance of caution, the family member is being testedm,' Reid wrote.
Meanwhile, school administrations in Washington state have been taking precautions of their own. In a letter to families, officials announced that Bothell High School (pictured) would be closed on Thursday
The Department of Health issued a letter that indicated that the risk to students at the high school was minimal and that they didn't believe the situation warranted closing the school.
However, Reid said she wasn't taking any chances and closed the school 'out of an abundance of caution'.
Support services staff have been taking initial steps to disinfect the areas where the staff member traveled on the campus.
Officials are also in the process of contacting the families of students and staff or visitors that the staff member came into contact with on Monday.
Coronavirus cases in the US have now risen to 60 with the addition of this case together with two more Diamond Princess cruise evacuees confirmed on Wednesday.
That figure includes 42 passengers who were aboard the Diamond Princess cruise ship, three people repatriated from China and 15 on US soil.
If community spread is confirmed in this case, this will spark major concerns across the US.
To date, the 59 other cases of the infection have been among people who traveled to Asia or were in close contact with people who had traveled there.
The US's first case that can't be traced to the virus's original source of origin follows hot on the heels of a similarly worrying statement from German officials Wednesday.
Germany's health minister, Jens Spahn, said new cases confirmed in Germany were 'partially no longer trackable' to the virus's original source in China or to hotspots.
New York City prepares for potential coronavirus outbreak
The US has taken measures to quarantine anyone thought to be carrying the disease, including 83 individuals currently in quarantine in Nassau County, New York.
New York City has been ramping up preparations for a potential coronavirus outbreak.
Mayor Bill De Blasio announced at a news conference Wednesday that the city had prepared at least 1,200 hospital beds ready for if or when the disease strikes.
New York City hasn't reported any patients under investigation, but in Chinatown people are already wearing protective masks (pictured). Nearby Nassau county has 83 residents in self-isolation
The city has also distributed 1.5 million face masks to residents and has requested 300,000 more.
De Blasio said he is also requesting the CDC expand its testing of travelers entering the US beyond China, to include Hong Kong, Iran, Italy, Japan, Singapore, South Korea, Taiwan, and Thailand.
'Right now, it is too narrowly focused on travelers coming out of China,' he said.
'We think that needs to be expanded to any traveler coming from a country that's seen a major surge in cases.'
De Blasio said the city is ready to handle a possible spread of the disease.
The plans come as around 700 people have been voluntarily quarantined in New York since February 3 after they returned to the city from parts of China where the disease is widespread.
New York State Health Department officials said that none of the people quarantined were showing symptoms of the disease but they had voluntarily checked into a 14-day self-isolation.
De Blasio said the self-quarantine protocol was working in the city. No active cases of the virus have yet been confirmed in New York City.
San Francisco and other California counties declare local emergencies
Several counties in the San Francisco Bay Area declared local emergencies Wednesday in response to the outbreak.
San Francisco Mayor London Breed declared a local emergency to make it easier for the city to combat possible cases of coronavirus.
'This declaration of emergency is all about preparedness,' Breed said at a news conference on Wednesday.
Several counties in the San Francisco Bay Area declared local emergencies Wednesday in response to the outbreak. Passengers wear masks while they wait for the flights at the LAX airport
San Francisco and Orange County declared states of emergency, while Orange County also backed a bid filed by the city of Costa Mesa to block coronavirus patients from being housed in their cities.
The move will, among other things, help the city get reimbursed by state and federal governments for money it spends on preparedness, Mayor London Breed said at a news conference
Similar declarations occurred in California's Santa Clara and San Diego counties.
Breed's declaration is in effect for the next seven days. A board of supervisors will vote on its continuation on March 3.
President Donald Trump insists risk to Americans is 'low'
Before news of the unknown origin case broke, only two cases of human-to-human transmission of coronavirus had been confirmed in the US.
However, CDC officials had previously warned that it was no longer a matter of 'if' but 'when' the virus would be active in US communities.
Fears are ramping up around the globe, as the number of new confirmed cases outside China has outpaced those inside the country for the first time.
The shock news that the disease may be spreading through community transmission came as President Donald Trump continued to insist that the risk to Americans is 'low' and that the nation is 'very ready' to tackle cases.
Trump announced Vice-President Mike Pence will be in charge of the nation's response to the disease at a White House press conference Wednesday night.
He also declared the US would spend 'whatever' it takes to beat coronavirus.
The shock news that the disease may be spreading through community transmission came as President Donald Trump continued to insist that the risk to Americans is 'low' and that the nation is 'very ready' to tackle cases
'We're very, very ready for this, for anything,' even if it's 'a breakout of larger proportions.'
'Every aspect of our society should be prepared. I think schools should get ready - just in case,' he added later.
The president also revealed one of the 15 Americans diagnosed with coronavirus in the US is 'pretty sick' and being treated in a hospital.
It was unclear if Trump knew about the 'unknown origin' case before the conference.
But Trump said the risk to Americans' health remained 'low,' and that the number of people diagnosed with the virus was small.
Trump said Pence would report to him.
Pence has no medical training; Trump praised his running of healthcare in Indiana when he was governor.
The vice president said extra personnel would be brought in to the White House for 'this whole of government response' to the mounting worldwide health crisis.
The president boasted that he had made 'early decisions' which had kept the level of coronavirus down in the US - but said that he would make sure government health workers have the resources they need.
'They can do whatever they want,' Trump said at the press briefing surrounded by top officials including Alex Azar, his Health and Human Services Secretary - who had denied he was being replaced by a czar just hours earlier.
'If Congress want to give us the money, we'll take the money.'
At the podium, Trump defended his administration's response to the coronavirus thus far, including shutting out non-citizens from China, where the first outbreak was reported.
'Decisions that were ridiculed from the very beginning,' the president said.
'A lot of people thought we shouldn't have done it that early, but we did and it turned out to be a very good thing.'
Asked directly about closing the borders to people from areas with worse infections he said: 'At the right time we may do that, right now it's not the right time.
'But at the right time, and we are checking people as they come through, specifically for the problem, the problem that we're dealing with.
'So we're checking a lot of people coming from South Korea, that's been hit pretty hard, Italy's been hit pretty hard. China, it's obvious what's happening in China, but again the numbers seem to be leveling off and going down in China which is very good news.'
He was also asked if he was prepared to quarantine entire cities - as has happened in Italy and China already - and replied: 'We do have plans on a much larger scale, should we need that.
'We don't think we're going to need it, but you always have to be prepared.'
Trump marveled at the number of people killed annually by the flu, explaining that in the US it numbered between 25,000 and 69,000 a year.
'That was shocking to me,' Trump said.
The president said just 15 people in the US have thus far had coronavirus, with eight returning home, one in the hospital and five fully recovered.
Trump also pulled out a piece of paper that he said listed the best prepared countries to deal with an epidemic, a product of research from Johns Hopkins University in Baltimore.
Trump also pulled out a piece of paper (pictured) that he said listed the best prepared countries to deal with an epidemic, a product of research from Johns Hopkins University in Baltimore
Trump announced Vice-President Mike Pence will be in charge of the nation's response to the disease at a White House press conference Wednesday night. Pence (right) has no medical training but Trump praised his running of healthcare in Indiana when he was governor
'John Hopkins, I guess, is greatly respected,' Trump said. 'We're rated No. 1 for being prepared.'
Trump also noted how the US brought in 40 people - American citizens - from a Japanese cruise ship where they had been diagnosed with the virus.
'We thought we had an obligation to do that,' he said. 'We found that it was an obligation that we have, we could have left them and it would have been really bad.'
The White House had asked for $2.5 billion in extra funding for the CDC, but had come under pressure to increase that spending by both Republicans and Democrats.
The press conference was an apparent attempt to calm fears over the virus, which has seen stock markets plunge and Democrats and Republicans both criticizing the official response.
Trump instead suggested that the Democratic 2020 field was largely responsible for the 2,000 point drop in the Dow Jones since Monday morning.
He went on to make reference to his well-known reputation for germaphobia, and provided safety tips for Americans to follow.
'I do it a lot anyway as you probably heard,' he said.
He gave guidance consistent with what public health officials have recommended: taking prudent steps to avoid viral transmissions, as with flu and seasonal colds.
'Wash your hands. Stay clean. You don't necessarily have to grab every hand rail unless you have to. You know, certain things that you do when you have the flu,' he advised.
Then the president told an anecdote.
'I mean, view this the same as the flu. When somebody sneezes, I try to bail out as much as possible when there's sneezing.
'I had a man come up to me a week ago. I hadn't seen him in a long time and I said how are you doing? He said, 'Fine.' He hugs me.
House Speaker, Nancy Pelosi (center, on Monday), who visited Chinatown in New York City on Monday, dismissed Trump Wednesday, saying: 'I don't think the president knows what he's talking about - once again'
'I said, 'Are you well?' He says no. He said, I have the worst fever and the worst flu. And he's hugging and kissing me. … I went back and started washing my hands. So you have to do that,' Trump said.
House Speaker, Nancy Pelosi, who visited Chinatown in New York City on Monday, dismissed Trump Wednesday, saying: 'I don't think the president knows what he's talking about - once again.'
When asked about the criticism made by Pelosi, he slapped back by calling the California Democrat 'incompetent.'
Trump also suggested under Pelosi, Democrats would lose the House again - and he said impeachment 'lifted my poll numbers up by 10 points.'
'She's trying to create a panic,' Trump said. 'And there's no reason to create a panic because we have done so good.'
Azar was on stage to see Pence made czar - hours after he denied claims that he was about to be replaced by an epidemic czar in the project to oversee the US's handling of the coronavirus outbreak.
He claimed after Trump spoke that he was still in charge. 'I'm still chairman of the task force,' he said.
'Having the vice president gives me the biggest stick one can have in the government, on this whole-of government approach. Not in the least.
'When this was mentioned to me I was delighted I get to have the vice president helping ... delighted, absolutely.'
Also on stage was the director of the National Institute of Allergies and Infectious Disease (NIAD) Dr Anthony Fauci, who reiterated the news that trials are set to begin for a vaccine for coronavirus, a record-setting three months after the virus was sequenced.
He added that the vaccine won't be ready for a year to a year-and-a-half.
At that point, it will make little impact on the current outbreak but, in the likely event that the virus is here to stay in coming years, Fauci expects a vaccine will be ready.
During the presser, Bernie Sanders, currently the Democratic frontrunner, sent out a statement blasting Azar for not guaranteeing during Congressional testimony earlier Wednesday that a coronavirus vaccine would be affordable to all.
'Under the Trump doctrine, if you are wealthy you can buy a vaccine and not succumb to the sickness. If you are poor or working class, you may have to get sick or even die,' Sanders said.
'That is an outrage. That is unacceptable. We need a vaccine that is available to all, not just those who can afford it.'
Respirator masks selling for nearly $10,000 on eBay
Several people are trying to capitalize off of the spread of the coronavirus by selling respirator masks for thousands of dollars on eBay.
One seller listed 80 boxes of the masks for $9,999.99 while a 20-pack is listed for $5,000.
Similar masks can be found online or in stores for less than $5.
Amazon has already warned sellers about selling masks that are 'not in compliance' with its pricing policies
According to Amazon's 'Fair Pricing Policy', sellers are required to set fair prices for its products that are not 'significantly higher than recent prices offered on or off Amazon'.
It's unclear if eBay will be taking this same approach and a DailyMail.com request for comment was not immediately returned.
Diamond Princess evacuees
The White House briefing came as the CDC confirmed the positive test results of an additional six cruise evacuees on Wednesday, including four that had already been announced by local health departments.
At least five of the new patients were evacuated from the Diamond Princess cruise ship last week.
They were then transported to three different quarantine sites: military bases in California and Texas and the National Quarantine Unit in Nebraska.
Two other people who were among the 800-some Americans repatriated from Wuhan, the epicenter of the outbreak in China, have also tested positive for coronavirus.
The CDC had advised against letting 14 American Diamond Princess passengers, whose coronavirus tests came back positive as they were about to board the evacuation flights to the US, continue on the cargo planes.
State Department officials ultimately overrode the health officials on the ground in Japan, where the ship had been quarantined.
CDC officials told Americans to expect US coronavirus cases to rise after the repatriation of the passengers of the cruise ship (pictured), which had the greatest number outside China
Of the 328 evacuated people, more than a dozen 'high risk' passengers were taken on to Nebraska's high-grade quarantine.
CDC officials previously said they expected to see additional cases among the cruise ship evacuees, and diagnoses have indeed rolled in.
On Wednesday, it was reported that dozens of passengers allowed off the Diamond Princess cruise ship developed symptoms.
Officials in Japan said they contacted 813 former passengers of the vessel who had previously tested negative for the virus, and found 45 are now showing symptoms.
All of those with symptoms have been asked to contact doctors and take new tests to check whether they are also infected.
The CDC gave a stark warning on Tuesday that US cities, communities and hospitals would need to ramp up preparations for the virus' spread as more cases were likely on their way.
'Now is the time for US businesses, hospitals and communities to begin preparing for the possible spread of COVID-19,' CDC officials posted on Twitter Tuesday afternoon.
Officials said more coronavirus cases are 'likely to be identified in the coming days, including more cases in the United States' and that 'person-to-person spread will likely continue to occur, including in the United States'.
The CDC's point person on the coronavirus outbreak, Deputy Director for Infectious Diseases Dr Nancy Messonnier had advised parents to talk to their kids' schools about 'teleschooling' in the event of quarantines or class cancellations amid an outbreak.
'I told my children that they are not at risk now, but we as a family need to prepare for significant disruption in our lives,' Dr Messonnier told reporters in a Tuesday press briefing.
In a bizarre twist, she is the sister of Rod Rosenstein, the former attorney general who oversaw the Robert Mueller special counsel investigation and who was a repeated target for Trump's ire.
World Health Organization warns coronavirus has pandemic potential
The global death toll from coronavirus has reached more than 2,800, with the vast majority in mainland China. There are more than 82,000 confirmed cases of the disease.
Earlier this week, the chief of the World Health Organization stopped short of saying the coronavirus crisis was at pandemic levels despite a sudden spike in cases.
Dr Tedros Adhanom admitted in a press conference Monday that the surge of COVID-19 infections was 'deeply concerning' but said he would not declare it a pandemic - which is defined as the uncontrolled worldwide spread of a new disease.
Dr Tedros Adhanom (pictured) admitted in a press conference Monday that the surge of COVID-19 infections was 'deeply concerning' but said he would not declare it a pandemic - which is defined as the uncontrolled worldwide spread of a new disease
He said: 'The sudden increase in new cases is certainly very concerning. There is lots of speculation about whether this outbreak has now become a pandemic.
'For the moment, we are not witnessing the uncontained global spread of this virus and we're not witnessing large scale disease or deaths.'
Instead, the UN-body said the crisis has already been a public health emergency of international concern – the highest warning level – for a month.
But fears of a pandemic have been mounting, with a surge in cases outside of China and deaths declared in Iran and Italy while Afghanistan, Iraq, Kuwait, Bahrain and Oman all confirmed their first cases.
The body, headquartered in Geneva in Switzerland, argues a pathogen must spread easily between humans across the world before it is called a pandemic.
The WHO said the current crisis is a cluster of cases in 36 countries and territories, which can be traced back to Asia.