WASHINGTON (AP) - U.S. officials advised Americans against most travel to Mexico on Monday as a swine flu virus that began there spread to the United States and beyond. With 40 cases now reported
in the U.S., President Barack Obama urged calm, saying there was reason for concern but not yet "a cause for alarm."
Dr. Richard Besser, acting director of the Centers for Disease Control and Prevention, said that so far the disease in the United States seems less severe than the outbreak in Mexico, where more than 1,600 cases have been reported and where the suspected death toll has climbed to 149. No deaths have been reported in the U.S, 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.
"We are taking it seriously and acting aggressively," Besser said. "Until the outbreak has progressed, you really don't know what it's going to do."
The U.S. stepped up checks of people entering the country by air, land and sea.
And Besser said a new U.S. travel advisory was being prepared suggesting "nonessential travel to Mexico be avoided."
The confirmed cases announced on Monday were double the 20 earlier reported by the CDC. Besser said this was due to further testing - not further spreading of the virus - in New York at a school in Queens, bringing the New York total to 28.
Besser said other cases have been reported in Ohio, Kansas, Texas and California. He said that, of the 40 cases, only one person has been hospitalized and all have recovered.
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 Homeland Security Secretary Janet 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 center of the outbreak, suspended schools nationwide. A European Union official advised against nonessential travel to parts of the U.S. and Mexico, while 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 traveler 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 travelers, 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 traveling to, from, or through Mexico, but had not canceled flights.
Besser said the best way to keep the disease from spreading is by everyday precautions such as frequent handwashing, covering up coughs and sneezes and staying away from work or school if not feeling well.
Besser said that for now he'd prefer people "not giving that little kiss of greeting that they're used to right now."
While the cases reported so far in the United States seem relatively mild, Besser said far more will be known about the disease's transmission traits and severity in a week or two. He said the particular virus at issue had not been seen before, either in the United States nor in Mexico.
U.S. authorities are not currently recommending that people put on masks in the workplace to protect against infection. The evidence "is not that strong" that the wearing of protective masks effectively limits the outbreak of such diseases, Besser said.
He 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.
A private school in South Carolina was closed Monday because of fears that young people who recently returned from Mexico might have been infected. Officials of Newberry Academy in Newberry, S.C., said some seniors on the trip had flu-like symptoms when they returned.
State Department of Health and Environmental Control spokesman Jim Beasley said test results on the students could come back as early as Monday afternoon. To date, there have been no confirmed swine flu cases in the state.
Overseas stock markets fell as investors worried that the outbreak could derail economic recovery. U.S. stocks fluctuated as the swine flu threatened the travel industry, with major indexes modestly lower by mid-afternoon.
The New York City school where 28 cases have now been confirmed
was closed Monday and Tuesday.
Also, 14 schools in Texas, including a high school where two cases were confirmed, will be closed for at least the next week. Some schools in California and Ohio also were closing after students were found or suspected to have the flu.
In Mexico, the outbreak's center, soldiers handed out 6 million face masks to help stop the spread of the virus that is suspected in up to 103 deaths. Most other countries are reporting only mild cases so far, with most of the sick already recovering.
Spain reported its first confirmed swine flu case on Monday and said another 17 people were suspected of having the disease. Also, three New Zealanders recently returned from Mexico are suspected of having it.
"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.
Associated Press writers Mark Stevenson and Olga R. Rodriguez in
Mexico City; Frank Jordans in Geneva; Mike Stobbe in Atlanta; Maria
Cheng in London and Eileen Sullivan and Robert Burns in Washington
contributed to this report.