A national incident was declared by UK health chiefs today after it emerged that polio could be spreading in the community once more.
The disease – thought to be resigned to history – has been spotted in sewage samples in parts of London.
It is an evolved version of a weakened form of the virus found in live attenuated vaccines, which use a modified piece of the virus.
But there are signs it is spreading between people as officials have picked up several samples from different people, each with…
