U.S. Declares Public Health Emergency, Confirms 20 Cases Around the Country

Dr. Anne Schuchat, director of the CDC's National Center for Immunization and Respiratory Diseases, said it is premature to say the disease in the United States is different than the one that has killed about 86 people in Mexico, and how serious this new virus is compared to typical flu viruses remains to be seen. On Sunday, Canada became the third country to confirm human cases of the unique virus.

Earlier today, Department of Homeland Security Secretary Janet Napolitano said the government declared a public health emergency, which will allow it to free up resources to tackle the issue.

At a White House press conference, Dr. Richard Besser, acting director of the Centers for Disease Control and Prevention (CDC), ensured Americans that the administration is taking aggressive steps to control the outbreak, but that more cases are likely to expect to emerge in the near future.

"Flu viruses are very unpredictable. Outbreak of infectious diseases are very unpredicatable," Besser said. "We view this more as a marathon. We think this will continue to spread but we are taking aggresive action."

There is no vaccination for the swine flu strain, which has elements of pig, bird and human strains. But officials said they have ramped up medical surveillance around the country and as part of the emergency declaration, freed up state and federal resources for prevention. Officials also emphasized the importance of individual care and good hygenic pratices.