There have been two cases in my county so far...
This is Dane County in Madison, WI
The first person returned from China and went directly to an emergency room, reporting exposure to the virus. He was diagnosed, then quarantined at home for 2 weeks, and he fully recovered.
The second person traveled within the US and had contact with someone with the virus. Upon returning home that person called medical authorities and was instructed how to safely come in for testing and medical care. This person is also under quarantine at home.
If people do this right - ask for help immediately after a potential exposure - the risk is reduced considerably. These two people are not spreading the virus. Doubtless there will be other people who don't take these measures, but I am thankful for those who do.