WASHINGTON - Confirming nearly 50 cases of swine flu in the United States, the Obama administration said Monday it was responding aggressively as if the outbreak would spread into a full pandemic. Officials urged Americans against most travel to Mexico as the virus that began there spread to the United States and beyond.
President Barack Obama urged calm, saying there was reason for concern but not yet "a cause for alarm."
Yet just in case, administration officials said that they were already waging a vigorous campaign of prevention, unsure of the outbreak's severity or where it would show up next.
U.S. customs officials began checking people entering U.S. territory. Millions of doses of flu-fighting medications from a federal stockpile were on their way to states, with priority given to the five already affected and to border states. Federal agencies were conferring with state and international governments.
"We want to make sure that we have equipment where it needs to be, people where they need to be and, most important, information shared at all levels," Janet Napolitano, head of the Homeland Security Department, told reporters.
Her briefing came shortly before the World Health Organization raised the severity of its pandemic alert level to four from three on a six-point scale. Level 4 means there is sustained human-to-human spread in at least one country. Level 6 is a full-fledged pandemic, an epidemic that has spread to a wide geographic area.
"We are proceeding as if we are preparatory to a full pandemic," Napolitano said.
She said travel warnings for trips to Mexico would remain in place as long as swine flu is detected.
Dr. Richard Besser, acting director of the Centers for Disease Control and Prevention, said that so far the disease in the United States seemed less severe than the outbreak in Mexico, where more than 1,600 cases had been reported and where the suspected death toll had climbed to 149. No deaths had been reported in the United States, and only one hospitalization.
"I wouldn't be overly reassured by that," Besser told reporters at CDC's headquarters in Atlanta.
He raised the possibility of more severe cases -- and deaths -- in the United States.
A European Union official warned against travel to parts of the United States as well as Mexico, but Besser said that seemed unwarranted.
State Department spokesman Robert A. Wood said the EU commissioner's remarks were his "personal opinion," not an official position, and thus the department had no comment. "We don't want people to panic at this point," Wood said.
Still Besser said of the situation, "We are taking it seriously and acting aggressively. ... Until the outbreak has progressed, you really don't know what it's going to do."
The United States stepped up checks of people entering the country by air, land and sea and issued a new U.S. travel advisory suggesting "nonessential travel to Mexico be avoided."
The number of U.S. cases rose to 48, the result of further testing at a New York City school, although none was fatal. Other U.S. cases have been reported in Ohio, Kansas, Texas and California.
Countries across the globe increased their vigilance amid increasing worries about a worldwide pandemic. Obama told a gathering of scientists that his administration's Department of Health and Human Services had declared a public health emergency "as a precautionary tool to ensure that we have the resources we need at our disposal to respond quickly and effectively."
"This is obviously a cause for concern and requires a heightened state of alert, but it's not a cause for alarm," Obama said. He said he was getting regular updates.
The Senate has yet to confirm a secretary of human services, a surgeon general or a director of CDC. The absence of those officials left Besser and Napolitano to brief reporters on the swine flu outbreak.
The quickening pace of developments in the United States in response to the spreading new flu strain was accompanied by a host of varying responses around the world.
Mexico, at the centre of the outbreak, suspended schools countrywide. China, Taiwan and Russia considered quarantines, and several Asian countries scrutinized visitors arriving at their airports.
U.S. customs officials began checking people entering U.S. territory. Officers at airports, seaports and border crossings were watching for signs of illness, said Customs and Border Protection spokesman Lloyd Easterling.
While "the borders are open," Easterling said officials were "taking a second look at folks who may be displaying a symptom of illness."
If a traveller reports not feeling well, the person will be questioned about symptoms and, if necessary, referred to a CDC official for additional screening, Easterling said. The customs officials were wearing personal protective gear, such as gloves and masks, he said.
The CDC can send someone to the hospital if they suspect a case, but no one is being refused entry. Also, the CDC is readying "yellow cards" with disease information for travellers, in case they later experience symptoms.The border monitoring resembles that done during the SARS epidemic earlier in the decade.
Multiple airlines, including American, United, Continental, US Airways, Mexicana and Air Canada, said they were waiving usual penalties for changing reservations for anyone travelling to, from, or through Mexico, but had not cancelled flights.
Napolitano urged Americans to take "common sense" precautions.
"Common sense means washing hands, staying home from work or school if you feel sick, covering your mouth if you cough or sneeze. These are straightforward and simple measures, but they can materially improve our chances of avoiding a full-fledged pandemic," she said.
Administration officials said about 11 million doses of flu-fighting medications from a federal stockpile have been sent to states in case they are needed -- roughly one quarter of the doses in the stockpile.
While there presently is no vaccine available to prevent the specific strain now being seen, there are antiflu drugs that do work once someone is sick. If a new vaccine eventually is ordered, the CDC already has taken a key preliminary step -- creating what's called seed stock of the virus that manufacturers would use.
Stock markets fell overseas and in the United States out of concern that the outbreak could derail economic recovery. Airline and other travel-related stocks suffered the sharpest losses.
