By Janet Raloff

Web edition: April 27, 2009

As numbers of swine flu cases have been swelling in Mexico in recent days, U.S. medical policymakers have been watching the details with bated breath. “We are closely monitoring the emerging cases of swine flu in the United States. This is obviously a cause for concern and requires a heightened state of alert. But it’s not a cause for alarm,” President Barack Obama noted this morning in his 9 a.m. address before the National Academy of Sciences in Washington, D.C..

“The Department of Health and Human Services has declared a public health emergency,” he said, “as a precautionary tool to ensure that we have the resources we need at our disposal to respond quickly and effectively.

“I’m getting regular updates on the situation from the responsible agencies and the Department of Health and Human Services. . . . the Centers for Disease Control will be offering regular updates to the American people. [Department of Homeland Security] Secretary Napolitano will be offering regular updates to the American people as well so that they know what steps are being taken and what steps they may need to take.

“But one thing is clear: Our capacity to deal with a public health challenge of this sort rests heavily on the work of our scientific and medical communities. And this is one more example why we can’t allow our nation to fall behind [in these fields].”