Did Thousands of Travelers from China for Three Months Carrying Wuhan Virus Not Begin Infection of Most of United States?

Translate:

Several hundred thousand people traveled from China in December and January, many of them returning to the U. S. from the Chinese Lunar New Year celebrations, and fleeing the wuhan virus outbreak, many of them infected of course, so considering the wuhan is more contagious than most, why would we not expect much of the U. S. to have been infected before the travel bans were enacted?