US Homeland Security Secretary Janet Napolitano speaks during a news briefing on the swine flu outbreak at White House in Washington, capital of the United States, on April 26, 2009. The US declared a public health emergency Sunday amid an outbreak of 20 confirmed cases of swine flu. [Xinhua]

The Obama administration on Sunday declared public health emergency, immediately after at least 20 cases have been confirmed of swine flu in the United States.

The Department of Health and Human Services "will declare today a public health emergency in the United States," Homeland Security Secretary Janet Napolitano told a White House briefing.

The emergency declaration was "standard operating procedure," Napolitano said, adding the declaration will "allows us to use medication and diagnostic tests that we might not otherwise be able to use, particularly on very young children, and it releases funds for the acquisitions of additional anti-virals."

Similar emergency declarations were issued for floods in recent months in the US states of Minnesota and North Dakota and President Barack Obama's inauguration in January, she said.

According to the secretary, US officials will begin asking travelers about illness if they are entering the country from areas with confirmed swine flu cases. Passengers won't be barred from getting into the United States. But they could be referred for further testing.

"Travelers who do present with symptoms, if and when encountered, will be isolated per established rules," she said.

"They will be provided both with personal protective equipment and we'll continue to emphasize universal hand washing."

A total of 20 swine flu cases have been confirmed in the United States, acting director of the Centers for Disease Control and Prevention Richard Besser said in the same briefing.

The 20 cases confirmed so far are in New York, Ohio, Kansas, Texas and California, Besser told a White House briefing. He also expected more cases and more severe illness among Americans.

Besser says things are moving fast and that authorities expect the virus to spread. But he assured Americans that health officials are taking action to minimize its impact.

(Xinhua News Agency April 27, 2009)