A swine flu pandemic will be officially declared when the disease begins to spread rapidly outside of North America, the chief of the World Health Organisation has said.
The WHO has already put the world on pandemic alert level five and will officially declare a pandemic if it raises the level to six, the highest possible.
This means that a large scale outbreak in the UK, Spain or any other country outside of North America will see the outbreak of H1N1 influenza A turn into a pandemic.
Speaking earlier this week, Dr Margaret Chan, director general of the World Health Organisation, said: ‘The world is in phase 5 now. This means that we need to maintain a high level of vigilance and monitor further international spread of the virus, and further spread in countries that are already reporting cases.
‘We do not know how long we have until we move to phase 6, which indicates we are in a pandemic. We are not there yet. The criteria will be met when we see, in one region outside North America, clear evidence of community-level transmission.’
Swine flu has now spread to 22 countries, with 1,516 confirmed cases and 30 deaths, but large scale outbreaks remain confined to Mexico and North America.