'We need to be very nimble in our ability to identify and understand the potential risks posed by new viruses emerging from unexpected sources.
'It's important to realise that viruses can emerge through routes that we haven't considered. We need to be alert to those risks and ready to act on them.'
As of January 2012, the World Health Organization has confirmed there have been 583 cases of H5N1 (avian flu) in humans leading to 344 deaths. There have been no human cases in the UK however the strain was found in a flock of turkeys in Suffolk in 2007 and in wild swans in Dorset in 2008.