Some Reports Put Number of U.S. Swine Flu Cases at 50

Officials in other nations around the globe responded to the threat of a possible pandemic. China, Taiwan and Russia considered quarantines, and several Asian countries scrutinized visitors arriving at their airports, the AP reported.

The European Union on Monday advised against nonessential travel to the United States and Mexico. Early Monday, Spain confirmed that a man hospitalized in the eastern part of the country had tested positive for swine flu, in what's believed to be Europe's first case of the disease. Health authorities were also testing 17 other possible cases in Spain, a major travel link between Mexico and Europe, The New York Times reported.

Responding Monday to the EU's travel advisory, the CDC's Besser said, "Based on the situation in the United States right now, I think it is premature to put travel restrictions on people coming to the United States. As the situation changes, that needs to be evaluated by different countries."

On Sunday, U.S. health officials declared a public health emergency in response to the swine flu outbreak.

Homeland Security Secretary Janet Napolitano said the declaration was a precautionary measure and did not mean that the threat posed by the outbreak was worsening. But, the move allows federal and state governments easier access to flu tests and medications, she said.

Napolitano said the federal government had 50 million doses of the antiviral flu medication Tamiflu, and a quarter of those doses were being released to states, if needed, "particularly prioritizing the states where we already have confirmed incidence of the flu."

On Monday evening, the U.S. Food and Drug Administration, in response to requests from the CDC, issued Emergency Use Authorizations to make diagnostic and therapeutic tools available to public health and medical personnel so they can identify and respond to the swine flu virus under certain circumstances. The agency issued these authorizations for the use of certain Relenza and Tamiflu antiviral products, and for the rRT-PCR Swine Flu Panel diagnostic test.

Napolitano also said Sunday that the Department of Homeland Security had started "passive surveillance protocols to screen people coming into the country."

"All persons entering the United States from a location of human infection of swine flu will be processed by appropriate CDC protocols," she said. "Right now, these are passive. They are looking for people and asking about: 'Are you sick? Have you been sick?' and the like. And if so, they can be referred over for further examination. Travelers who do present with symptoms will be isolated."

Meanwhile, in Mexico, authorities continued to take dramatic steps to try to contain the outbreak. Government officials have canceled all school until May 6, and the Mexico City government is considering a complete shutdown, including all public transportation. And the Cinco de Mayo parade celebrating Mexico's defeat of a French army on May 5, 1862 and Mexico City's traditional May 1 parade have been canceled, the AP said.

Some of the U.S. cases involved people who had recently returned from trips to Mexico, federal officials said. The two cases reported in Kansas involved a husband and wife who had recently been to that country. And The New York Times reported that some of the students at St. Francis Preparatory School, in Queens, had recently come back from Mexico as well.

More information

For more on swine flu, visit the U.S. Centers for Disease Control and Prevention.