POLIO FOUND IN LONDON SEWAGE, FIRST SINCE `80s

Polio has been detected in sewage samples in London, the first sign since the 1980s that the virus could be spreading in Britain, but no cases have been found, authorities said.

The risk of infection from the disease, which causes paralysis in children in under one per cent of cases, was also low because of high vaccination rates, the U.K. Health Security Agency said.

The agency nevertheless encouraged parents to make sure their children were vaccinated after the discovery of the virus during routine waste water surveillance.

Nationwide vaccination levels are above the 90 per cent needed to prevent outbreaks, but London's coverage rates among the undertwos has dipped below that in recent years.