Swine Flu Outbreak Not a Pandemic at This Point

May 4 -- SUNDAY, May 3 (HealthDay News) -- Although the number of swine flu cases continued to climb Sunday, the World Health Organization said there is no clear sign yet that the scope of the outbreak has reached pandemic proportions.

That doesn't mean it won't, however.

"At the present time, I would still propose that a pandemic is imminent because we are seeing transmission to other countries," Dr. Michael J. Ryan, director of the World Health Organization (WHO) global alert and response team, said in a teleconference from Geneva, Switzerland, on Sunday. "We have to expect that Phase 6 will be reached. We have to hope that it is not."

As of Sunday morning, the WHO Web site was reporting 787 confirmed cases of swine flu in 17 countries. Mexico has reported 506 cases, with 19 deaths. The United States has confirmed 226 cases in 30 states, according to statistics released Sunday by the U.S. Centers for Disease Control and Prevention.

Currently, the outbreak is gauged a Phase 5, meaning the disease is spreading throughout communities in at least two countries in one of WHO's six regions -- in this case the United States and Mexico. To reach Phase 6, the geographic spread of the disease would have to occur in at least one other country in another region.

However, the Associated Press reported that Mexico's health secretary said on Sunday that the swine flu epidemic in his country apparently is waning.

Jose Angel Cordova told a news conference that Mexico's swine flu death toll remained at 19, while the number of confirmed cases increased slightly, from 473 to 506. Mexico is believed to be the source of the epidemic.

"The evolution of the epidemic is now in its declining phase," Cordova said during a news conference.

U.S. health officials were also cautiously optimistic on Sunday.

"There are several encouraging signs," Dr. Anne Schuchat, interim deputy director for the CDC's science and public health program, said during a teleconference Sunday. "We heard reports that the H1N1 activity might be leveling off in Mexico -- it's too soon to be certain that that's the case."

"Today, I do think we do see some encouraging signs, but we are remaining cautious," Schuchat added. "We have a novel infectious disease -- a new H1N1 virus -- and it's too soon for us to know exactly how this is going to evolve or play out. We can't predict with certainty what the weeks and months ahead will look like. I don't think we are out of the woods yet.

"It's good news that we've only confirmed one death and we have 30 hospitalizations, but it's too soon to say the extent of this disease," she said. "But from what I know about influenza, I do expect more cases, more severe cases, and I do expect more deaths, and I am particularly concerned about what will happen in the fall."

Schuchat noted that the United States needs to be ready for next year's seasonal flu, as well as be prepared for what this new virus might do in the fall. "We are working actively and aggressively to be one step ahead," she said. "We don't know if the virus will come back in the fall harder than it did right now."

There are 30 hospitalizations so far, and some of the cases are severe, Schuchat said. Most of those hospitalized are adolescents and young adults, she noted.

Since schools are the focus of many of the outbreaks, the CDC has issued new recommendations for school closings.

Because children may shed the virus longer than adults, the agency is now recommending that affected schools remain closed for two weeks instead of one, Schuchat said during a teleconference on Saturday.

The U.S. Education Department has said that more than 430 schools had closed, affecting about 245,000 children, the Wall Street Journal reported.

Nancy Cox, chief of the influenza division of the National Center for Immunization and Respiratory Diseases at the CDC, did deliver some welcome news on the nature of the virus itself on Friday. She said that a preliminary analysis of the H1N1 strain found that it lacks certain "virulent characteristics" that made the 1918 flu pandemic strain so deadly.

And the new Secretary of Health and Human Services, Kathleen Sebelius, has made the decision to buy 13 million more courses of antivirals to replenish the antiviral stockpile, Schuchat said. "We don't know if we are going to need them, we just wanted to be ready," she said.

In addition, the United States has shipped 400,000 regimens of antivirals to Mexico at the request of the Mexican government, Schuchat added.

Meanwhile, President Barack Obama has urged Americans to stay calm, noting that it was not clear whether the global outbreak of the never-before-seen flu strain was any worse than "ordinary flus." But, he added, agencies across the U.S. government are preparing for the worst, according to the AP.

In a strange twist on Saturday, swine flu was discovered for the first time during this outbreak in pigs. WHO officials reported on the organization's Web site that the virus had been detected in sick pigs on a farm in Alberta, Canada.

Until now, it was not known whether the virus could infect pigs, even though its genetic makeup clearly points to pigs as the source of the pathogen. However, in this case a human appears to have infected the livestock, not the other way around, the WHO reported. A worker on the farm had traveled to Mexico, come back to Canada and fallen ill. The swine are now under quarantine. WHO officials stressed that the swine flu cannot be transmitted through the consumption of pork products.

(As of May 3, 2009, 11:00 AM ET)