Miranda Carnero, 18, and Jorge Juarez, 18, wear masks as they wait to clear U.S. Customs crossing from Ciudad Juarez, Mexico.AP PHOTO
MEXICO CITY — The World Health Organization raised its global alert level on the spreading swine flu virus Monday, but stopped short of declaring a global emergency — even as the United States said it was acting as if the outbreak would grow into a full pandemic.
The U.S. government advised Americans against most travel to Mexico and ordered stepped up border checks in neighboring states. The European Union health commissioner advised Europeans to avoid nonessential travel both to Mexico and parts of the United States.
The suspected number of deaths rose to 149 in Mexico, the epicenter of the outbreak with nearly 2,000 people believed to be infected.
The number of U.S. cases doubled to 40, 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. Worldwide there were 73 cases, including six in Canada, one in Spain and two in Scotland.
While the total cases were still measured in hundreds, not thousands, Mexican Health Secretary Jose Angel Cordova said the epidemic was entering an extremely dangerous phase, with the number of people coming down with the disease mushrooming even as authorities desperately ramped up defenses.
“We are in the most critical moment of the epidemic. The number of cases will keep rising, so we have to reinforce preventative measures,” Cordova said at a news conference.
The WHO raised the alert level to Phase 4, meaning there is sustained human-to-human transmission of the virus causing outbreaks in at least one country.
Its alert system was revised after bird flu in Asia began to spread in 2004, and Monday was the first time it was raised above Phase 3.
“At this time, containment is not a feasible option,” as the virus has already spread to several other countries, said WHO Assistant Director-General Keiji Fukuda.
Putting an alert at Phases 4 or 5 signals that the virus is becoming increasingly adept at spreading among humans. That move could lead governments to set trade, travel and other restrictions aimed at limiting the disease’s spread.
The WHO’s Phase 6 is the pandemic phase, characterized by outbreaks in at least two regions of the world.
Many experts think it may be impossible to contain a flu virus already spreading in several countries.
Russia, Hong Kong and Taiwan said they would quarantine visitors showing symptoms of the virus amid global fears of a pandemic, an epidemic spread over a large area, either a region or worldwide.
President Barack Obama said the outbreak 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 virus in the United States seems less severe than in Mexico. Only one person has been hospitalized in the U.S.
“I wouldn’t be overly reassured by that,” Besser told reporters at CDC’s headquarters in Atlanta, raising 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.”
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,” said Janet Napolitano, head of the Homeland Security Department.
“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.
Mexico canceled school at all levels nationwide until May 6, and the Mexico City government said it was considering a complete shutdown, including all public transportation, if the death toll keeps rising. Labor Secretary Javier Lozano Alarcon said employers should isolate anyone showing up for work with fever, cough, sore throat or other signs of the flu.
Amid the warnings, the Mexican government grappled with increasing criticism of its response. At least two weeks after the first swine flu case, the government has yet to say where and how the outbreak began or give details on the victims.