CNN  — 

The United States has its first confirmed case of a new virus that appeared in Wuhan, China, last month, the US Centers for Disease Control and Prevention announced Tuesday. The coronavirus has already sickened hundreds and killed six people in Asia.

CDC officials said the United States will be more strict about health screenings of airplane passengers arriving from Wuhan.

The patient, who is not being named, is in isolation at Providence Regional Medical Center in Everett, Washington. He is in his 30s and lives in Snohomish County, Washington, just north of Seattle. He had recently returned from Wuhan.

He arrived at Seattle-Tacoma International Airport on January 15, before any health screenings for the Wuhan coronavirus began at US airports. He sought medical care on January 19. The CDC and Washington state are now tracing the people he was in contact with to see if he might have spread the disease to someone else.

“We believe the risk to the public is low,” said John Wiesman, secretary of health for the state of Washington.

The patient became ill four days after arriving in the United States and sought care. Based on the patient’s symptoms and travel history, doctors suspected the novel Wuhan coronavirus and sent specimens to the CDC in Atlanta, where tests Monday confirmed the virus.

The patient is faring well but is still being kept in isolation out of an a