Nobody dares predict the possible human toll should a bird flu pandemic break out in China, with its 1.3 billion people and 14.2 billion domestic fowl - accounting for about one-fifth of the global population for each.
When asked if the government had made an assessment of a worst-case scenario, Shu Yuelong , director of the National Influenza Centre, said: 'I can only tell you that the World Health Organisation estimated that 5 million to 150 million people would die worldwide if there is a pandemic.
'It is very difficult to estimate the possible toll in China - it really depends whether it takes place in the cities or the countryside.'
What makes China so vulnerable to bird flu is the way it keeps its huge number of domestic poultry, mostly in backyard farms with other livestock such as pigs. Domestic pigs can serve as a 'mixer' because they can easily become a conduit through which a virus such as H5N1 can mutate into a new human flu virus.
Adding to the problem is the fact that many farms are exposed to wild fowl or migratory birds, potential carriers of H5N1. No province is spared the risk, with all of China exposed to three major migratory routes.
'There are 14 billion poultry in China and to monitor the health of 14 billion is an enormous challenge,' said Henk Bekedam, the World Health Organisation's China representative.
