Source: United States Centers for Disease Control and Prevention
Link: https://www.cdc.gov/coronavirus/2019-ncov/cases-in-us.html
According to the official CDC website, last updated February 26, 2020:
CDC is closely monitoring an outbreak of respiratory illness caused by a novel (new) coronavirus. The outbreak first started in Wuhan, China, but cases have been identified in a growing number of other international locations, including the United States. This page will be updated regularly on Mondays, Wednesdays, and Fridays.
As of February 26th, 2020, the CDC has only tested 445 Americans since January 21st.
Those official figures represent about 15 tests per day. One cannot measure what isn’t tracked. As the experts say, continue to listen and remember this is a fluid situation that’s constantly changing (just like the virus).