MEXICO CITY — Mexico reported three new deaths from the swine flu epidemic Saturday and urged citizens not to let their guard down against a virus that has killed 19 in people in Mexico and is spreading across Asia and Europe.
Health Secretary Jose Angel Cordova said Mexico's confirmed swine flu cases jumped to 473, including the 19 deaths. The previous confirmed death toll in Mexico was 16, and many more deaths are suspected.
Mexico's last confirmed swine flu death occurred Wednesday, Cordova said. However, he said 11 people were suspected to have died from the virus in the last 24 hours. The news came after the toll in Mexico appeared to be leveling off and Cordova said hospitals were handling fewer patients with swine flu symptoms.
The global caseload was nearing 800 and growing. Cases outside Mexico suggested the new swine flu strain is weaker than feared, but governments moved quickly anyway to ban flights and prepare quarantine plans. Experts warned the virus could mutate and come back with a vengeance.
A World Health Organization official said he thought the agency's infectious disease alert level ultimately would be raised to its highest point.
"I would still propose that a pandemic is imminent because we are seeing the disease spread," Michael Ryan, the agency's director of global alert and response, said in Geneva. "We have to expect that Phase 6 will be reached; we have to hope that it is not."
The level will be raised when the agency sees evidence of sustained person-to-person transmission of the virus outside North America. So far, he emphasized, that has not occurred, with the exception of a handful of cases.
"These viruses mutate, these viruses change, these viruses can further reassort with other genetic material, with other viruses," Ryan said. "So it would be imprudent at this point to take too much reassurance" from the small number of deaths.
The U.S. Centers for Disease Control and Prevention also said it's too early to declare victory.
"We have seen times where things appear to be getting better and then get worse again," said Dr. Anne Schuchat, the U.S. agency's interim science and public health deputy director. "I think in Mexico we may be holding our breath for some time."
In the first known reported case of the new, mutated virus infecting another species, pigs in the province of Alberta have become infected and are under quarantine. Canadian and U.S. officials said the pigs are recovering and do not pose a food safety risk.
Ryan said the WHO would send 72 developing countries 2.4 million courses of the antiviral agent Tamiflu from its emergency stockpile. The drug's manufacturer, Roche, said that it would send an additional 3 million doses and that it was scaling up production of the drug.
President Barack Obama used his weekly radio address to reassure the public that his administration is squarely confronting the outbreak. He underscored that 50 million courses of flu treatment were stockpiled in anticipation of any outbreak, preparations he credited the Bush administration for.
Later, he spoke with Mexican President Felipe Calderon about efforts to contain the virus.
Worldwide, Italy confirmed its first case of the disease in a man who recently had returned from Mexico, and Ireland confirmed its first case. Costa Rica also confirmed a case, the first in the Caribbean outside Mexico.
Swine flu cases have been confirmed in 18 countries, but experts believe the actual spread and the number of cases is much bigger than the numbers suggest.