SATURDAY, May 2, 2009 (HealthDay News) -- The swine flu continued to spread across the United States on Saturday, as federal health officials reported there are now 160 confirmed cases in 21 states, with 13 hospitalizations and one death.
"We have information that this novel virus continues to spread with increasing cases and increased states affected, and we are acting actively and aggressively. Our highest priority is the health and safety of the American public," Dr. Anne Schuchat, interim deputy director for the science and public health program at the U.S. Centers for Disease Control and Prevention, said during a noon teleconference Saturday. "We have seen times when things appear to be getting better and then get worse again. With a new virus like this, we don't know how it's going to behave or change over time."
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 noted. However, what individual communities decide to do is up to them and their own analysis of the situation, she added.
The U.S. Education Department said Friday that more than 430 schools had closed, affecting about 245,000 children, the Wall Street Journal reported.
Meanwhile, the scope of the swine flu outbreak in Mexico might not be as great as once thought and the number of new cases there appear to be leveling off.
As of Saturday morning, there were 443 confirmed cases in Mexico, according to the Associated Press.
On Friday, The New York Times reported that only 397 of 908 suspected cases in Mexico that were tested turned out to actually be the H1N1 virus. Sixteen of those people have died.
Mexico had reported about 2,500 suspected cases as of Friday, but the real numbers could be half of that if further testing follows the same pattern, the Times reported.
"Apparently the rate of infection is not as widespread as we might have thought," Jose Angel Cordova, Mexico's health minister, told the newspaper. The materials needed for the test were provided to Mexico by CDC officials.
"While reports from Mexico appear to be encouraging and some are cautiously optimistic, we can't afford to let down our vigilance," Schuchat said during the Saturday teleconference.
However, 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 during a teleconference that a preliminary analysis of the H1N1 strain finds 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, in the last 24 hours, the United States has shipped 400,000 regimens of antivirals to Mexico, believed to be the source of the global outbreak, 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.
If swine flu "is relatively mild on the front end, it could come back in a more virulent form during the actual flu season," he said at the end of a Cabinet meeting on Friday.
Elsewhere, the World Health Organization reported late Friday that the number of confirmed cases worldwide has risen from 364 in 13 countries, with 10 deaths, to 615 cases in 15 countries. And Asia announced its first case, in Hong Kong. Officials there quarantined an entire tourist hotel where the victim, a traveler from Mexico who entered via Shanghai, had stayed Thursday night before getting sick, according to the Times. On Saturday, South Korea reported its first case of swine flu.
On Monday, a 23-month-old Mexican boy who had traveled to Houston for medical treatment died, becoming the first -- and so far, only -- fatality in the United States.
Speaking at a press conference on Thursday, CDC Acting Director Dr. Richard Besser said that while most cases appear to be mild, "six of the cases have been hospitalized, including the unfortunate case we reported yesterday of the child in Texas who passed away."
And scientists were racing to produce a vaccine against the new flu strain, but the shots -- if needed at all -- wouldn't be available until fall at the earliest, U.S. health officials said Thursday.
"We think 600 million doses is achievable in a six-month timeframe" from that fall start, U.S. Health and Human Services Assistant Secretary Craig Vanderwagen told lawmakers.
On Friday, U.S. health officials told reporters that six countries -- the United States, Canada, the Netherlands, Mexico, Germany and New Zealand -- have all shared samples of the virus for testing to further the vaccine effort.
"The good news is that the genes of all of the viruses we have examined to date are 99 to 100 percent identical," Cox said. "This means that it will be somewhat easier for us to produce an influenza vaccine."
"We are aggressively taking the very early steps that are necessary for vaccine manufacture should a decision be made go ahead and ramp up to full-scale production," Cox added.
The current plan is to have vaccine manufacturers complete production of next year's seasonal flu vaccine, then, if necessary, switch to the production of the H1N1 vaccine, Schuchat said.
The flu strain is a combination of pig, bird and human viruses, prompting worries from health officials that humans may have no natural immunity to the pathogen.
Meanwhile, the U. S. Food and Drug Administration and the Federal Trade Commission warned consumers Friday to avoid Internet sites and other promotions that offer products claiming to diagnose, prevent, treat or cure the swine flu virus.
"Consumers who purchase products to treat the novel 2009 H1N1 virus that are not approved, cleared or authorized by the FDA for the treatment or prevention of influenza risk their health and the health of their families," Michael Chappell, acting FDA Associate Commissioner for Regulatory Affairs, said in a news release. "In conjunction with the Federal Trade Commission, the FDA has developed an aggressive strategy to identify, investigate and take regulatory or criminal action against individuals or businesses that wrongfully promote purported 2009 H1N1 influenza products in an attempt to take advantage of the current flu public health emergency."
As with the previously tested strains of the swine flu virus, new testing has found that the pathogen remains susceptible to the two common antiviral drugs Tamiflu and Relenza, according to the CDC.
On Wednesday, the WHO raised the swine flu epidemic level from 4 to 5, signifying that a pandemic is imminent, and urged countries to implement their pandemic plans. And on Thursday, WHO said it would cease calling the virus "swine flu," using instead its scientific name -- H1N1 influenza A -- to help reduce confusion over the danger posed by pigs. Pork consumption does not transmit infection.
Along with Hong Kong, South Korea, Mexico and the United States, swine flu infections have now been reported in Canada, Denmark, New Zealand, Britain, Germany, Spain, Israel, The Netherlands, Switzerland and Austria.
For more on swine flu, visit the U.S. Centers for Disease Control and Prevention.