Confirming 40 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."
But administration officials said they were already waging a vigorous campaign of prevention, unsure of the outbreak's severity or where it would show up next.
"We want to make sure that we have people where they need to be, equipment where it needs to be and, most of all, information shared at all levels," Janet Napolitano, head of the Homeland Security Department, told reporters.
The World Health Organization "now has us at a level 3" out of six levels of intensity, with six being a full pandemic, she said.
"Even if they raise the level today, our preparations are as if they had already been raised. We are proceeding as if we are preparing to a full pandemic," she said.
She said travel warnings for trips to Mexico would remain in place as long as swine flu is detected.
