U.S. Declares Public Health Emergency in Response to Swine Flu

On Saturday, Dr. Anne Schuchat, the CDC's Interim Deputy Director for Science and Public Health Program, told reporters that, because of the wide geographic spread of the virus so far, the outbreak is already "beyond containment."

But she added that U.S. health officials had numerous tools to fight the illness' spread and protect the health of Americans. The viruses found in the United States are resistant to two antiviral medications -- amantadine and rimantadine -- but are susceptible to the antivirals oseltamivir (Tamiflu) and zanamivir (Relenza), Schuchat said.

Schuchat said steps were already being taken to devise a vaccine against this strain of swine flu, although the process takes time. "We are taking the initial steps in terms of preparing the seed virus to hand off to the industry partners, to produce large quantities. But you know it takes months to produce a vaccine," she said.

In response to the developments in North America, countries around the world planned quarantines, tightened rules on pork imports and tested airline passengers for fevers as global health officials tried Sunday to come up with uniform ways to battle the outbreak. Nations from New Zealand to France reported new suspected cases and some warned citizens against travel to North America, the AP said.

World Health Organization Director-General Margaret Chan held teleconferences with staff and flu experts around the world but stopped short of recommending specific measures to halt the disease beyond urging governments to step up their surveillance of suspicious outbreaks, the news service said.

In Mexico, the government has ordered schools closed and all public events have been suspended for the time being, including more than 500 concerts and other gatherings in the city of 20 million residents. Even churches stood empty Sunday, the AP said.

While Mexico's flu season is usually over by now, health officials noticed a sizeable uptick in flu cases in recent weeks. According to a report published in The New York Times on Friday, World Health Organization experts said that most deaths among Mexican patients with swine flu have involved healthy young adults.

That could be worrisome, experts say. Seasonal flus usually strike hardest at infants and the elderly, but pandemic flus -- such as the 1918-19 Spanish flu, which killed an estimated 20 million to 40 million people worldwide -- often strike young, healthy people, the newspaper reported.

Swine flu is a respiratory disease of pigs caused by type A influenza. Swine flu does not normally infect humans. However, human infections do occur, usually after exposure to pigs. Symptoms resemble those of the regular flu, including sore throat, coughing and fever.

More information

For more on swine flu, visit the U.S. Centers for Disease Control and Prevention.