A man residing near Seattle has been diagnosed with a new coronavirus after traveling to China, the first confirmed case in the United States and the first outside Asia, the Centers for Disease Control and Prevention said Tuesday.

The man in his 30s returned to the United States last Wednesday from Wuhan in central China -- the epicenter of the outbreak of the pneumonia-like illness. The man has been isolated and is in good condition, the health protection agency said at a press conference.

An official assured that the risk of the novel coronavirus to the American public at large "remains low at this time," while noting the confirmation that human-to-human spread is occurring in Asia raises the level of concern about the virus.

According to the agency, the individual -- a resident of Washington state -- reached out to a local medical provider about his condition on Sunday, and received treatment. Laboratory testing of a specimen led the center to confirm on Tuesday the first U.S. case of the coronavirus.

The individual did not take a direct flight from Wuhan to an airport serving the Seattle area. He reported that he did not visit the Wuhan seafood market where local health authorities believe the virus originated, and did not know anyone who was ill.

"He was just traveling from that area (of Wuhan)," a U.S. health official said.

From last Friday, the agency began implementing public health entry screening at San Francisco International Airport, Los Angeles International Airport, and John F. Kennedy International Airport in New York. No individuals have been referred to hospital or discovered with infections through the screening, according to the agency.

The agency said it will expand screening to airports in Atlanta and Chicago.

China has confirmed 440 cases of the new coronavirus, with nine deaths reported. The virus has also been confirmed in Japan, South Korea, Taiwan and Thailand.

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