A centre to fight emerging infectious diseases was yesterday opened by the World Health Organisation in collaboration with disease control and prevention experts in Guangdong, where Sars emerged more than three years ago. 'Today is a great day. With your support, the WHO collaboration centre is formally set up and marks a major milestone in southern China's public health history,' said centre director Deng Feng , seconded from the Guangdong Centre for Disease Control and Prevention. Vice-Health Minister Wang Jiefu pledged that China would positively participate in international co-operative efforts to prevent and control emerging infectious diseases. 'We can't tell where and when they will emerge or how they will harm humans or how fast they will spread,' he said. Within months of Sars being contained in July 2003, the even more pathogenic H5N1 bird flu virus struck in Asia and has now spread to Europe, the Middle East and Africa. Shigeru Omi, the WHO's regional director for the Western Pacific, said many countries did not have sufficient public health infrastructure or the capacity to prevent and control emerging infectious diseases. Most countries had traditional centres for disease control and response systems, but many did not function as early warning systems and their laboratory capacity to confirm pathogens was limited, he said. The selection of Guangdong as the venue for the WHO Collaborating Centre for Surveillance, Research and Training on Emerging Infectious Diseases was not random, said the WHO's country director in Beijing, Henk Bekedam. 'The Guangdong [centre for disease control] has long been a tried-and-tested warrior in the fight against infectious diseases. The expertise and commitment of its personnel are well known in the story of Sars and beyond,' he said. China's top Sars expert, Zhong Nanshan, said it was significant to the province, country and world that the centre had been set up in southern China because it was where 'chances of animal transmission [of diseases] to humans are greater ... and this is also an area with a high outbreak of bird flu'.