04/27/2009 - Confirming 42 cases of swine flu in the U.S., the Obama administration said Monday it was responding aggressively as if the outbreak would spread into a full pandemic. Officials urged Americans against most travel to Mexico as the virus that began there spread to the United States and beyond.
President Barack Obama urged calm, saying there was reason for concern but not yet "a cause for alarm."
They deny being the source and say they're cooperating with health officials. But Sreenivasan reports that just last year, a report by the nonprofit Pew Charitable Trusts warned that hog farms could become breeding grounds for new strains of the flu.
"The warm conditions and the close proximity of animals being able to pass viruses back and forth and to the human workers," said Bob Martin of the Pew Environmental Group. "It's a situation ripe for the development of a novel virus."
Read the full article U.S. Bracing For Swine Flu Pandemic on the CBS News Web site.