The Trump administration on January 31 placed a ban on foreign nationals who had visited China within the past 14 days, with exceptions for immediate family members of US citizens and permanent residents.
US citizens who have recently visited the Hubei province, where the outbreak started, must submit to a 14-day quarantine when re-entering the US. A second plane was headed to Wuhan on Sunday to remove US citizens in the city, which would be the second instance of such an extraction effort, and may not be the last.
Plus, the US State Department increased its travel warning for China to a Level 4 on Sunday, recommending US citizens "do not travel" to the country because of the virus.