British Health officials have declared it a national incident
In Britain, traces of the polio virus have been found in sewers in east London.
Experts have noted the discovery is the first sign of transmission in the UK since 1984.
The discovery in Beckton has prompted authorities to declare a national incident, as they attempt to track cases.
The virus - which in rare cases causes paralysis - has been mostly eradicated worldwide due to vaccines.
Sky's health correspondent, Ashish Joshi, says occasional cases are not unheard of:

Company Behind Chatbot Calls For Paused Global AI Development
Israeli Ministers Ben-Gvir And Smotrich Barred From Travel To Ireland
Fine Gael Faces Criticism Following Recent EU Migration Decisions
Ceasefire Agreed Between Israel And Lebanon
18 Dead After Russian Overnight Attack On Ukraine
21 Year Old Jailed For Planned Terror Attack On 2024 Taylor Swift Concert
Iran Claims To Have Targeted US Airbase Overnight
Two Teenagers Among Those Dead After Bus Collides With Train In Belgium