COURTESY BY: https://www.dawn.com/ WASHINGTON: America should prepare for a “surge upon a surge” in coronavirus cases as millions of travelers return home after the Thanksgiving holiday, top US scientist Anthony Fauci warned on Sunday. The United States is the worst-affected country, with 266,074 Covid-19 deaths, and President Donald Trump’s administration has issued conflicting messages on mask-wearing, travel and whether the outbreak is under control. “There almost certainly is going to be an uptick because of what has happened with the travel,” Fauci told CNN’s “State of the Union” as the Thanksgiving long…