Polio is believed to be spreading in Britain for the first time in decades as health experts warn the NHS to watch out for paralysis cases. The UK Health Security Agency has repeatedly detected the poliovirus in London's sewage works and has called on families to check children are fully vaccinated.
The last community outbreak in Britain was in the 1970s but health officials insist the current risk to the population is low. Oral vaccines against polio offered abroad contain an “attenuated” form of the virus - weakened in a laboratory so it cannot cause disease.
These vaccine-derived forms of the virus remain in stool and are occasionally picked up in routine UK testing of sewage samples, conducted in London and Glasgow. The oral vaccines are different to the polio injections offered in the UK which contain a completely inactivated form of the virus.
