On average, the US Federal Reserve distributes $34b in paper notes every year. The Fed has begun quarantining physical dollars that it repatriates from Asia before recirculating them in the U.S. financial system as a precautionary measure against spreading the virus.
According to the CDC, it “may be possible” to transmit the virus through objects that have had direct contact with it, but person-to-person contact is the main means of spreading the disease. The CDC recommends U.S. residents returning from China and other high-risk countries stay home for 14 days.