WHO: Swine Flu Now A Pandemic, 1st In 41 Years

She would not say which country tipped the world into the pandemic, but WHO flu chief Keiji Fukuda said the situation from Australia seemed to indicate the virus was spreading rapidly there — more than 1,300 cases were reported by Thursday.

In Chile, authorities have identified almost 1,700 cases to WHO.

Many health experts said the world has been in a pandemic for weeks but WHO became too bogged down by politics to declare one. In May, several countries urged WHO not to declare a pandemic, fearing it would cause social and economic turmoil. At the time, WHO said it would rewrite its pandemic definition to avoid announcing one.

But with the recent surge in cases across Europe, Chile, Australia and Japan, the agency was under increasing pressure to acknowledge a pandemic.

"This is WHO finally catching up with the facts," said Michael Osterholm, a flu expert at the University of Minnesota.

David Ropeik, an expert in risk perception and communication at Harvard University, says the word pandemic is less frightening than when emerged during worries about bird flu a few years ago.