Federal health officials confirmed Tuesday that a case of the new coronavirus has been diagnosed in Seattle. In addition, the Centers for Disease Control and Prevention said they will begin screening passengers for the virus at two additional airports: the Hartsfield-Jackson Atlanta International Airport and Chicago's O'Hare International Airport.
The outbreak has spread from the central Chinese city of Wuhan to cities including Beijing and Shanghai, the CDC said Tuesday. Cases have also been reported outside China, including in South Korea, Thailand and Japan. At least six have died.
The patient in Washington state, a resident of Snohomish County, is a male in his 30s. The CDC said the man arrived in the U.S. around Jan. 15 after visiting Wuhan. He had not, however, visited the seafood market where this virus is said to have originated.
Health officials said the man did not have any symptoms when he arrived, but had read about the viral outbreak online. When he started to develop symptoms, he reached out to his health care provider.
He's currently in good condition but remains hospitalized "out of an abundance of caution," health officials said.
"We are grateful the patient is doing well," Dr. Nancy Messonnier, director of the CDC's National Center for Immunization and Respiratory Diseases, said Tuesday during a call with reporters. She added the risk of spreading the illness to others remains low.
The case in the U.S. comes amid rising concern that the illness could be transmitted through so-called super-spreaders — highly infectious patients with the ability to sicken dozens at once.
Nearly all of the 300-plus cases have been reported in China, including at least 14 health care workers who have fallen ill with the respiratory virus, a coronavirus known as 2019-nCoV.
It's unclear whether those workers were all infected in the same place, but if so, "it just smacks of a super-spreader event," said Michael Osterholm, an international infectious disease expert at the University of Minnesota.
That's when one patient inexplicably produces much higher levels of a virus in his or her lungs, giving the patient the ability to infect dozens of people at a time. Osterholm said super-spreader cases occurred during two well-known coronavirus outbreaks: the SARS and the MERS epidemics. The 2003 SARS outbreak reached more than two dozen countries, sickening 8,098 people. Nearly 800 died.
"For those of us who dealt with SARS and MERS, it's like déjà vu all over again," Osterholm told NBC News. "When you see super-spreaders, you know you've got a problem."
There is no indication the patient in Washington state is a "super-spreader."
China's National Health Commission confirmed 298 cases as of Tuesday evening. The majority have been reported in or near the city of Wuhan, and linked to a food market with live animals. Since the strain was first detected in December, the number of cases and their geographic spread has increased rapidly.
Severe cases have generally been limited to older adults with underlying health conditions. But increasingly, Osterholm said, younger, otherwise healthy adults are falling ill.
What is a coronavirus?
Coronaviruses are a group of viruses that can cause a range of symptoms including a runny nose, cough, sore throat and fever. Some are mild, while others are more likely to lead to pneumonia. They're usually spread through direct contact with an infected person.
The coronavirus gets its name from the crown-like spikes on its surface, according to the CDC. (Corona is Latin for crown.) Including the newly identified form of the virus, there are a total of seven coronaviruses that can infect humans, the CDC says.
There is no specific treatment for the new virus, and no vaccine to prevent it. The National Institutes of Health confirmed Tuesday they are in the "very preliminary stages" of research to develop a vaccine for the new virus, but declined to provide details.
The outbreak is coinciding with massive travel in and out of China in advance of the Lunar New Year on Jan. 25, and prompted the CDC last week to start screening passengers arriving from Wuhan at New York's John F. Kennedy International Airport, the San Francisco International Airport and Los Angeles' LAX. On Tuesday, the CDC announced that it would be screening passengers at two additional airports: Alanta's Hartsfield–Jackson and Chicago's O'Hare. All passengers whose flights originate in Wuhan will be rerouted to one of these five airports.
On Wednesday, the World Health Organization will meet to discuss whether to declare the outbreak a global health emergency. Such a move would help guide countries on how they should respond, usually by offering financial and/or political support. It could also recommend against practices that could be detrimental to affected regions, such as travel and trade restrictions.
"One thing that we've seen in outbreaks in the past is countries try to put up travel bans or propose restrictive travel in an attempt to stop the spread of an outbreak," said Alexandra Phelan, an adjunct professor at Georgetown Law who works on policy issues related to infectious diseases.
North Korea, for example, has reportedly closed its border to foreign tourists until the current coronavirus outbreak is under control.
But, Phelan explained, such policies are ineffective because people still cross borders. "When you put travel bans in place, people don't go through the normal processes. You lose the opportunity to give people medical information, conduct appropriate screening or provide medical treatment," Phelan said.