The WHO said there are increasing fears bird flu might mutate into a virulent form of human flu that could kill hundreds of millions of people around the world, the Washington Times reported Thursday.
"It's coming," said Dr. Lee Jong-wook, the WHO's director-general. He stresses intensified planning is immediately needed. "When the pandemic starts, it will simply be too late."
The latest avian flu strain, blamed for 63 deaths in Vietnam, Thailand, Cambodia and Indonesia, has spread to poultry in Russia and Kazakhstan.
Dr. Michael Osterholm, head of the University of Minnesota's Center for Infectious Disease Research and Policy, told the Washington Times an avian flu pandemic could kill nearly 2 million people in the United States. Worldwide, he foresees as many as 300 million deaths.