
A scientist in Washington State believes coronavirus may have been spreading for six weeks before it was detected, and there could be a 'few hundred' people currently infected amid an 'already substantial outbreak'.

At least 74 confirmed cases of COVID-19 had been reported as of Sunday afternoon with the majority being on the west coast of the United States but new cases were confirmed in Rhode Island - where a patient in their 40s had traveled to Italy in mid-February - and Illinois where the third ‘presumptive case of novel coronavirus,’ was announced. Two people have made full recoveries in Illinois.

But anxious shoppers descended on supermarkets, stocking up on supplies like bottled water, canned food and Clorox wipes after more than half a dozen California residents were diagnosed with the disease in recent days.

The number of confirmed infections in Washington reached eight Sunday as two men in their 60s - both with underlying health conditions - were in critical condition. One was stable at Valley Medical Center in Renton, the other was at Virginia Mason.

Trevor Bedford of the University of Washington said the illness has likely spread within the community as none of the people confirmed to be infected had recently traveled.

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A new coronavirus study 'strongly suggests that there has been cryptic transmission in Washington State (pictured) for the past 6 weeks,' a scientist has said. In three new cases confirmed near Seattle the victims don't have a history of recent travel

Arrows on a diagram show how coronavirus case WA2 stems from the same tree as WA1, the first two cases reported in the US

Travelers wear protective mask as they walk through in terminal 5 at O'Hare International Airport in Chicago, Sunday. In Illinois, the third ‘presumptive case of novel coronavirus,’ was announced

Rhode Island Director of Health Nicole Alexander-Scott, left, and R.I. Gov. Gina Raimondo, right, face reporters during a news conference, Sunday. Alexander-Scott took questions on what she described as the state's first presumptive positive case of coronavirus. Officials said the person is in their 40s and had traveled to Italy in February of 2020

But anxious shoppers descended on supermarkets, stocking up on supplies like bottled water, canned food and Clorox wipes after more than half a dozen residents were diagnosed with the disease in recent days. A shopper is pictured in Oregon

Bedford said a team at the Seattle Flu Study had compared the first reported case of COVID-19 in the United States to the second case, and found that it was on the same evolutionary tree.

Sharing a diagram, Bedford tweeted Saturday: 'This strongly suggests that there has been cryptic transmission in Washington State for the past 6 weeks.'

Bedford posted on social media that case WA2 is likely to have come from case WA2 as they appear almost identical in make-up.

The academic also noted that they were discovered in the same area of Washington State, Snohomish County, as he put the probability value at 0.3. Anything less than 0.5 is statistically significant and effectively rules out the chance the findings are random.

'It's possible that this genetic similarity is a coincidence and these are separate introductions. However, I believe this is highly unlikely. The WA1 case had a variant at site 18060. This variant is only present in 2/59 viruses from China,' Bedford continued.

'I'd assess the p-value for this coincidence at 2/59=0.03 and so is statistically significant. Additionally, these two cases are geographically proximal, both residing in Snohomish County.

'I believe we're facing an already substantial outbreak in Washington State that was not detected until now due to narrow case definition requiring direct travel to China.'

Bedford said they will be working closely with Public Health Seattle and King County as well as the Washington Department of Health to fully investigate the outbreak.

The virus, immunity and evolution expert added that they hope to provide an update on the number of infections in Washington State soon.

'An update, because I see people overly speculating on total outbreak size. Our best current expectation is a few hundred current infections,' Bedford tweeted Saturday. 'Expect more analyses tomorrow.'

Coronavirus wasn't detected in the country before January 19 and the initial cases were in Washington

Sonya Tran, of Randolph, Massachusetts, front, and Bobby Ratanasim, of Providence, Rhode Island, behind center, wear protective masks while playing a Nintendo game, Thursday, in Boston. Tran and Ratanasim said concerns about the coronavirus played a role in wearing masks to the conference

Zhang Bin, right, walks with a friend along a street, both wearing protective masks in the Koreatown section of Los Angeles on Friday

A 'medically high-risk' male in his 50s died of coronavirus overnight Friday in Kirkland hospital EvergreenHealth

Scientists not affiliated with the research said the results did not necessarily surprise them and pointed out that for many people - especially younger, healthier ones - the symptoms are not much worse than a flu or bad cold.

'We think that this has a pretty high rate of mild symptoms and can be asymptomatic. The symptoms are pretty non-specific and testing criteria has been pretty strict, so those combinations of factors means that it easily could have been circulating for a bit without us knowing,' said Justin Lessler, an associated professor of epidemiology at the Johns Hopkins Bloomberg School of Public Health.

'And that was what a lot of us was thinking was likely.'

The man who died Friday was a 'medically high-risk' patient in Kirkland hospital EvergreenHealth, just two miles from Life Care in Kirkland.

Two confirmed cases in Washington are connected to the long-term care home, Life Care where a total of 25 staff and 27 residents of the nursing facility were showing symptoms of coronavirus, health officials said Friday.

But the new cases reported Sunday were not from the Life Care Center, Katie Ross, a spokeswoman for the Washington Health Department, said.

The Washington Public Health Laboratories confirmed the test results for both cases were positive but 'haven't identified a connection', King County Public Health said in a press release.

The CDC and local health officials sent an emergency response team to Life Care to try to control the escalating situation.

Frank Riedo, the medical director of infection control at EvergreenHealth Hospital, previously did not seem to rule out the possibility the cases are related.

'At the present time, we do not see a connection between the two. But there are some evolving threads that are being investigated,' said Riedo.

'I think … what we're seeing is the tip of the iceberg. We're seeing the most critically ill individuals. Usually that means there's a significant percentage of individuals with less severe illness floating around out there. So in all likelihood there is ongoing low level transmission.'

The death was just two miles from Life Care in Kirkland (pictured). A staff member blocks the view as a person is taken by a stretcher to a waiting ambulance from a nursing facility

At the Life Care nursing facility where concerns of a mass outbreak are mounting, but officials are maintaining the cases are unconnected

'We are very concerned about an outbreak in a setting where there are many older people, as we would be wherever people who are susceptible might be gathering,' Dr. Jeff Duchin, the health officer for Seattle and King County, said.

Duchin added that older adults and people with underlying health conditions like diabetes, heart or lung disease should be especially careful to protect themselves by washing their hands, not touching their faces, and avoiding contact with people who are sick.

The Life Care facility provides 24-hour care for residents, including physician and nurse coverage, many of whom have long-term and chronic conditions.

News of the potential outbreak in the facility is concerning given the higher danger of coronavirus being fatal to individuals who are less healthy or already have pre-existing conditions.

A spokesperson for Life Care told DailyMail.com that the facility was not accepting any visitors or new admissions, and was monitoring all residents and associates for the virus.

A map shows the four previously announced 'unknown origin' coronavirus cases

They said the restricted access had only been put in place earlier that morning, the same day the two cases were confirmed and outbreak fears emerged.

Medical staff wearing protective clothing and masks were pictured transporting a patient on a stretcher into an ambulance at the Life Care facility on Saturday.

The CDC is working with the facility to try to get a handle on the situation, they said, but the individual said they could not confirm reports that the CDC was sending in an emergency response team to the home.

Executive director Ellie Basham said in a statement that the facility is monitoring the situation closely.

'Current residents and associates are being monitored closely. As is normal this time of year, there are various cold and flu-like symptoms being exhibited from residents and associates,' the statement emailed to DailyMail.com read.

'The health department has advised us to monitor for an elevated temperature, cough and shortness of breath. We're consulting with the health department and possibly sending patients to a local hospital for formal COVID-19 testing.'

Several Kirkland firefighters have also been quarantined after they responded to Life Care facility over the last week, according to Seattle Times.

'It impacted multiple crews,' Kellie Stickney, a city of Kirkland spokesperson, said.

The city has not stated where the firefighters are being quarantined.

Worldwide, the outbreak that began in Wuhan, China has sickened at least 83,652 people and killed 2,862 in 54 countries.

Community spread with no traceable origin has been identified in California, Washington, Oregon.

The US will start screening travelers for coronavirus and ramp up production of masks and test kits as the government scrambles to reassure Americans while the disease spreads and businesses cancel conferences and flights.

Donald Trump said on Sunday that travelers to the United States from countries at high risk of coronavirus would be screened before boarding and upon arrival, without specifying which countries.

Delta Air Lines Inc on Sunday said it is suspending until May flights to Milan in northern Italy where most of that country's coronavirus cases have been reported. Flights will continue to Rome. American Airlines Group Inc announced a similar move late on Saturday.

The United States has imposed limits on travelers who have visited Iran and recommended against travel to hard-hit areas of Italy and South Korea.

Trump said on Saturday that the United States was also considering shutting the country's southern border with Mexico to control the spread of the virus, adding, 'We hope we won't have to do that.'

Mexico has reported four coronavirus cases. Its foreign ministry said on Saturday that both governments are in 'close and effective communication, especially the health authorities.'

Delta Air Lines Inc on Sunday said it is suspending until May flights to Milan in northern Italy where most of that country's coronavirus cases have been reported. Flights will continue to Rome. American Airlines Group Inc announced a similar move late on Saturday

Vice President Mike Pence said the government had contracted 3M Co to produce an extra 35 million respiratory masks a month. He urged Americans not to buy the masks, which he said were only needed by healthcare workers. Honeywell International Inc is the other major U.S. mask producer.

U.S. Surgeon General Jerome Adams asked the public to stop buying masks, saying they're ineffective against coronavirus.

Pence, named by the president to be the point-person overseeing the government's response, said more than 15,000 virus testing kits had been released over the weekend. And, the administration is working with a commercial provider to distribute 50,000 more, he said.

The vice president said testing was among the first issues raised by governors he's spoken with so far. Several states have begun their own testing, including Washington state, Oregon and Illinois.

'We're leaning into it,' Pence said.

U.S. Health and Human Services Secretary Alex Azar said more than 3,600 people already have been tested for coronavirus and the capability exists to test 75,000 people. He forecast a "radical expansion of that" in the coming weeks.

Mike Pence, whom Trump appointed last week to run the White House's coronavirus response, said Americans should brace for more cases, but that the 'vast majority' of those who contracted the disease would recover

The United States has 75,000 test kits for coronavirus and will expand that number 'radically' in coming weeks, Azar told ABC's This Week on Sunday.

He also told Fox News that clinical trials of a coronavirus vaccine would start in six weeks but that a vaccine will likely not be available this season.

Democrats, who will challenge Trump for the presidency in the November 3 election, have criticized his administration for downplaying the crisis and not preparing for the disease to spread in the United States.

Pence, whom Trump appointed last week to run the White House's coronavirus response, said Americans should brace for more cases, but that the 'vast majority' of those who contracted the disease would recover.

'Other than in areas where there are individuals that have been infected with the coronavirus, people need to understand that for the average American, the risk does remain low. We're ready,' Pence told NBC's 'Meet the Press'.