Polio has been detected in sewage samples in the British capital, the first sign since the 1980s that the virus could be spreading in the country, but no cases have been found, authorities said.
The risk of infection from the disease, which causes paralysis in children in under 1 per cent of cases, was also low because of high vaccination rates, the UK Health Security Agency (UKHSA) said.
The agency nevertheless encouraged parents to make sure their children were vaccinated after the discovery of the virus during routine wastewater surveillance particularly those who may have missed shots during the Covid-19 pandemic.
Nationwide vaccination levels are above the 90pc needed to prevent outbreaks, but London’s coverage rates among the under-twos have dipped below that in recent years.