WASHINGTON - 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 United States, President Barack Obama said there was reason for concern but not yet "a cause for alarm."
Dr. Richard Besser, acting director of the Centers of 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 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 initially 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.
The best way to keep the disease from spreading, he said, is by taking everyday precautions such as frequent handwashing, covering up coughs and sneezes and staying away from work or school if not feeling well.
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 Mexico.
He said authorities are not currently recommending that people across the country 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, he said.
Besser said that for now he'd prefer to focus on regular handwashing, and people "not giving that little kiss of greeting that they're used to right now."
He said about 11 million doses of flu-fighting medications from a federal stockpile have been sent to states in case they are needed. That's roughly one quarter of the doses in the stockpile, he said.
There is no vaccine available to prevent the specific strain now being seen, he said. However, 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.
Meanwhile, the European Union health commissioner advised Europeans to avoid nonessential travel to Mexico and the United States.
Besser said that including the U.S. in the advisory seemed unwarranted at this time.
State Department Robert A. Wood said the commissioner's remarks were his "personal opinion," not an official EU position, and therefore the department had no comment.
"We don't want people to panic at this point," Wood said.
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