(CBS/AP) Governments are racing to find and contain pockets of swine flu around the globe, seeking to stem both the threat of a pandemic and public panic.
"We're preparing in an environment where we really don't know ultimately what the size or seriousness of this outbreak is going to be," U.S. Homeland Security Secretary Janet Napolitano said Sunday.
The virus officially spread to Europe on Monday, with Spanish authorities saying one case had been confirmed and 17 more people suspected of infection.
Health Minister Trinidad Jimenez said the confirmed case was found in a young man who had recently been in Mexico.
Jimenez told a press conference Monday that the man was responding well to treatment and was not in serious condition.
The EU's health commissioner urged Europeans on Monday to postpone nonessential travel to the United States or Mexico due to the swine flu.
"They should avoid traveling to Mexico or the United States of America unless it is very urgent for them," said Health Commissioner Andorra Vassiliou
In Mexico, the outbreak's epicenter, soldiers handed out 6 million face masks to help stop the spread of the novel virus that is suspected in up to 103 deaths.
CBS News correspondent Hari Sreenavasin reports that many schools, restaurants, daycare centers and other businesses were closed in the Mexican capital city Monday.
Most other countries are reporting only mild cases so far, with most of the sick already recovering. Cases have also been confirmed in Canada - six - and the U.S. - 20 - and other countries from Spain to New Zealand were investigating whether other people with flulike symptoms really have this new swine flu or something else.
There is not a global pandemic yet, but waiting until scientists know if the new virus is going to spread rapidly and easily would be too late.
The U.S. declared the health emergency amid confusion about whether new numbers really mean ongoing infections - or just that health officials had missed something simmering for weeks or months. But the move allows the government to ship roughly 12 million doses of flu-fighting medications from a federal stockpile to states in case they eventually need them.
A spokesman for the World Health Organization, Peter Cordingly, said the virus was spreading quickly in Mexico and the southern U.S. and has the potential to become a pandemic and a global threat.
President Obama is set to address the health crisis Monday in remarks to a meeting of the nation's top scientists.
Dr. Richard Besser, acting chief of the Centers for Disease Control and Prevention, told CBS' The Early Show on Monday that the U.S. government was taking all the needed precautions, and that officials would enact "additional measures as necessary."
The U.S. has not put any travel bans in place, but Besser told The Early Show, "Personally I would think hard about non-essential travel to parts of Mexico that are affected."
The U.S. government has outlined a multiagency response, but seemed determined to project an air of calm, reported CBS News correspondent Kimberly Dozier. They likened their efforts to planning for a hurricane that may never come.
"Really, that's what we're doing right now. We're preparing in an environment where we really don't know ultimately what the size or seriousness of this outbreak is going to be," Napolitano told reporters.
"We do think this will continue to spread but we are taking aggressive actions to minimize the impact on people's health," said Dr. Besser on Sunday.
The World Bank said it would send Mexico $25 million in loans for immediate aid and $180 million in long-term assistance to address the outbreak, plus advice on how other nations have dealt with similar crises. Mexico officials say the flu strain may have sickened 1,614 people since April 13 but laboratory testing to confirm that and how many truly died from it - at least 22 so far out of the 103 suspected deaths - is taking time.
Mexican health authorities asked any residents with flu-like symptoms to work from home Monday if possible.
The European Union called Monday for an emergency meeting to assess the implications of the flu.
"What I can say to European citizens is, 'yes, we are following the situation very closely and very carefully together with all the member states'," EU Commission President Jose Manuel Barroso said in Athens.
Worldwide, attention focused sharply on travelers.
"It was acquired in Mexico, brought home and spread," Nova Scotia's chief public health officer, Dr. Robert Strang, said of Canada's first confirmed cases.
A New York City school where eight cases were confirmed will be closed Monday and Tuesday, and 14 schools in Texas, including a high school where two cases were confirmed, will be closed for at least the next week.
China, Russia and Taiwan began planning to quarantine travelers arriving from flu-affected areas if they have symptoms. Italy, Poland and Venezuela advised citizens to postpone travel to affected parts of Mexico and the U.S.
Singapore, Thailand, Japan, Indonesia, South Korea and the Philippines were checking for signs of fever among passengers arriving at airports from North America. In Malaysia, health workers in face masks took the temperatures of passengers as they arrived from a flight from Los Angeles.
Travelers with flu-like symptoms would be given detailed health checks.
Multiple airlines, including American, United, Continental, US Airways, Mexicana and Air Canada, are waiving their usual penalties for changing reservations for anyone traveling to, from, or through Mexico, but have not canceled flights.
Officials along the U.S.-Mexico border were asking health care providers to take respiratory samples from patients who appear to have the flu. Travelers were being asked if they visited flu-stricken areas.
The U.S. hasn't advised against travel to Mexico but does urge precautions such as frequent hand-washing while there, and began questioning arriving travelers about flu symptoms.
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