Top international health experts from the World Health Organization (WHO) (from L) Takeshi Kasai, Zhou Weigong and Paul Cox gather at the control room of the WHO headquarters in Manila, 02 April 2007, where a team of experts monitor a simulated outbreak of a bird flu pandemic in Cambodia. The rapid containment exercise, Panstop 2007, involves a mock scenario in which a strain of bird flu with the potential for a human pandemic is discovered in a village in Cambodia. The WHO says there have been 281 cases of bird flu infection among humans and 169 deaths worldwide, mostly in Southeast Asia.