WASHINGTON — Warning that the worst is yet to come, U.S. officials Sunday declared the rapid spread of swine flu to be a public health emergency and freed up 12.5 million doses of antiviral medication to help fight the disease, which has now infected 20 people in five states.
The move comes as state and local authorities, the Centers for Disease Control and Prevention and the international health community step up public awareness, testing and surveillance in an effort to stop the disease before it becomes a global epidemic. On Sunday, four more cases were confirmed in the Canadian province of Nova Scotia.
In Mexico, where the outbreak originated, nearly 90 people have died and thousands of others have become ill from swine flu in the last several weeks.
The World Health Organization said the new swine flu strain has "pandemic potential." A flu pandemic occurs when a new influenza virus emerges, people have little or no immunity to it and there's no vaccine for it.
No deaths have been reported in the United States, but officials confirmed Sunday that eight students at a New York City high school tested positive for the disease after dozens had complained of flu-like symptoms. Some of the students had recently returned from a spring break trip to Cancun, Mexico. The school has been closed as a precaution.
Authorities have confirmed seven more cases in California, two in Kansas and Texas and one in Ohio. More cases are expected in the coming days
"As we continue to look for cases, I expect that we're going to find them. We've ramped up our surveillance around the country to try and understand better what is the scope, what is the magnitude of this outbreak," said Dr. Richard Besser, the acting director of the CDC.
President Obama is getting regular briefings and updates on the outbreak and the steps being taken to address the problem. Homeland Security Secretary Janet Napolitano is heading the federal effort to deal with the outbreak, but numerous other departments, including Health and Human Services and Agriculture, are also involved.
The virus spreading throughout the U.S. appears to be the same strain that's infected Mexico, but health officials are unsure why the U.S. outbreaks haven't been as severe. To date, all U.S. flu victims have recovered, and only one has been hospitalized.
That could change, however, since infectious diseases, and the flu virus in particular, are unpredictable, Besser said.
"Given the reports out of Mexico, I would expect that over time, we're going to see more severe disease in this country," Besser warned. . . . "We do think that this will continue to spread, but we are taking aggressive actions to minimize the impact on people's health."
A "pandemic severity index," developed by the CDC, ranks flu outbreaks in terms of expected deaths and is modeled after the hurricane warning system that the National Weather Service uses.
The mildest flu strains, those expected to kill fewer than 90,000 Americans, would be known as Category 1 outbreaks. The most severe, a Category 5 flu epidemic, could kill more than 1.8 million U.S. residents.
Sunday's health emergency declaration frees up federal, state, and local resources for disease prevention. The move allows agencies to conduct diagnostic tests, if necessary, on young children. It also okays the release 12.5 million courses of antiviral medications Tamiflu and Relenza from the nation's strategic stockpiles. The drugs will go to states in need, with priority given to those with confirmed cases.
The Department of Defense is making an additional 7 million courses of Tamiflu available, said Napolitano.
Both Tamiflu and Relenza help lessen the severity of flu symptoms and shorten the course of the illness, but it's unclear if the drugs will work against the swine flu, Besser said. Since there's no vaccine for swine flu, health officials are trying to determine whether a vaccine could be developed, Besser said.
In addition, the U.S. Department of Agriculture is screening and testing livestock to make sure the food supply isn't infected, Napolitano said. She added that the disease can't be contracted from eating pork.
Travelers entering the United States from infected locations will be subject to "passive surveillance," in which they'll asked questions about their health. Those with symptoms will be isolated, given protective equipment and could be subject to further testing, Napolitano said. Although the State Department hasn't issued an official travel advisory for Mexico, that could change.
"Right now, we don't think the facts warrant a more active testing or screening of passengers coming in from Mexico," Napolitano said. . . . "But again, this is a changing dynamic that we may increase or decrease that as the facts change over the next 24, 48, 72 hours."
She urged travelers to check the Department of State Web site for updates.
While the source of the virus is unclear, Besser said it doesn't look as if bio-terrorism was a factor in the outbreak. "There's nothing that we have seen in our work that would suggest anything but a naturally occurring event," Besser said.
He added that the swine flu strain is like other new flu strains that have emerged. "It's an assortment — it's got genetic components from a number of sources, including human, swine, and avian sources. And that's something that you see with new strains," Besser said.
ABOUT SWINE FLU:
A respiratory disease of pigs, swine influenza infections occur most commonly among humans who're in close proximity to pigs. However, the disease also can spread from person to person. Highly contagious, swine flu has the same symptoms as regular human flu, including fever, cough, sore throat, headache, chills and fatigue.
WHAT YOU SHOULD DO:
Health officials are urging people who've developed flu-like symptoms after traveling to areas where the disease has emerged to contact their doctors to determine what testing and treatment is appropriate.
They say that all people also should cover their noses and mouths with a tissue when coughing or sneezing; wash hands often with soap and water, especially after a cough or sneeze and use alcohol-based hand cleaners when possible. Avoid touching your eyes, nose and mouth since germs cans spread easily spread that way. The CDC also advises avoiding contact with sick people.
Homeland Security Secretary Janet Napolitano urged all citizens to help curb the spread of the disease.
"The government can't solve this alone," she said. "We need everybody in the United States to take some responsibility here. If you are sick, stay home. Wash your hands, take all of those reasonable measures; that will help us mitigate, contain how many people actually get sick in our country," Napolitano said Sunday.
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