U.S. officials declared a public health emergency Sunday as eight cases of swine flu were identified in New York and one was announced Ohio, bringing the total of confirmed U.S. cases to 20.
In a briefing at the White House, the acting head of the Centers for Disease Control and Prevention, Dr. Richard Besser, warned Americans to prepare for a widespread outbreak, yet urged the public to remain calm.
Also Sunday, Homeland Security Secretary Janet Napolitano said the government would release a quarter of its 50 million-unit strategic reserve of antiviral medications, which combat the disease in infected patients, to states where outbreaks had occurred.
Canadian officials, meanwhile, said that four cases had been confirmed in Nova Scotia and two in British Columbia, marking the first time that this particular strain had appeared north of the U.S. border. All six Canadian cases were mild, like those in the United States.
Several other countries have reported influenza-like illnesses that they suspect might be swine flu in travelers returning from Mexico, but as of Sunday evening, none of them had been confirmed.
Nonetheless, many nations moved quickly to limit the disease's spread, in many cases appearing to be near panic. Some, such as Poland and Venezuela, warned against traveling to the United States or Mexico. Others, such as Russia and Brazil, began screening incoming international air travelers for signs of high fever.
China, Russia and Taiwan said they would quarantine returning passengers with flu symptoms.
In Mexico, Health Secretary Jose Angel Cordova said five more deaths had occurred from influenza in that country overnight, bringing the death total to 103. Two of the new cases were confirmed as swine flu, for a total of 22 confirmed swine flu deaths. It was not clear how many of the others were caused by the virus.
The number of suspected swine flu cases in Mexico, meanwhile, rose to more than 1,600.
Swine flu is "serious enough to be a great concern to this White House and to this government," White House press secretary Robert Gibbs said on NBC's Meet the Press, adding that President Barack Obama is receiving frequent updates on the situation.
