By Smitha Mundasad and Philippa RoxbyHealth reportersImage source, Getty ImagesUK health officials say they have detected the virus that causes polio in a concerning number of sewage samples in London.There have been no recorded cases of people ill with the disease in the UK but doctors are on alert. What is polio and how does it spread? It can be a serious infection, caused by a virus which spreads easily,
from the BBC
