PARIS, May 31 (Reuters) - A bird flu pandemic is almost certain to occur in the long term, but the likelihood of a large-scale outbreak in humans in the next few years is less clear, a World Health Organization official said on Thursday. "The chances of a (bird flu) pandemic over the long term is almost certain .... but over the next few years it seems uncertain," Keiji Fukuda, head of the WHO's global influenza programme, told a conference on bird flu in Paris.
