The Centers for Disease Control and Prevention confirmed Thursday the first person-to-person transmission of the coronavirus in the U.S., CNBC reports.

The state of play: The disease has already killed at least 171 people in China and infected over 8,000. However, CDC Director Robert Redfield told reporters that the agency's "assessment remains that the immediate risk to the American public is low."

Officials said that a Chicago woman who traveled to Wuhan, China, the center of the outbreak, spread it to her husband. He is in good condition.

They are monitoring 21 other individuals in Illinois for possible infection.

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