Traces of polio virus found in London sewage as health officials declare national incident Officials believe there has been some spread between closely linked individuals in northeast London - probably extended family members.
Traces of the polio virus have been found during a routine sewage inspection in London, leading the UK Health Security Agency to declare a national incident.
Health officials are now concerned about the community spread of the virus after samples were collected from the Beckton Sewage Treatment Works in London, but have stressed the risk to the public is extremely low.
Several closely-related polio viruses were found in sewage samples taken between February and May. It has continued to evolve and has now been classified as a 'vaccine-derived' poliovirus type 2 (VDPV2).
Officials believe there has been some spread between closely linked individuals in northeast London - probably extended family members - and that these people are now shedding the type 2 poliovirus strain in their faeces.
Urgent investigations will try to establish the extent of community transmission and to identify where it may be occurring.