United States health officials delivered a clear message Tuesday: serious measures could be required to stem the new coronavirus. One top official described the spread of the disease in the U.S. as inevitable.That tone is in clear contrast to the messages coming from the White House. After a sharp dip in the stock market Monday, President Trump tweeted that the disease "is very much under control in the USA." He is scheduled to address the nation again tonight.This episode: congressional correspondent Susan Davis, White House correspondent Franco Ordoñez, and chief economics correspondent Scott Horsley.