A ‘national incident’ has been declared after evidence of polio was found in sewage samples in north east London.
People are now being urged to ensure their polio vaccines are up to date.
The UK Heath Security Agency (UKHSA) has established the national incident to check for cases as a precaution.
Working with the Medicines and Healthcare products Regulatory Agency (MHRA), the UKHSA has found polio in sewage samples collected from the London Beckton Sewage Treatment Works, which serves around four million people in north and east London.
Polio virus has only been detected in sewage samples and no cases of paralysis have been reported, the UKHSA has stressed.
Most people who get polio do not have symptoms but some suffer mild, flu-like issues such as a high temperature, extreme tiredness, headaches, vomiting, a stiff neck and muscle pain.
In one in 100 to one in 1,000 infections, the polio virus attacks the nerves in the spine and base of the brain.
This can cause paralysis, usually in the legs, that develops over hours or days. If the breathing muscles are affected, polio can be life-threatening.
The virus found in recent samples has evolved in England and is now classified as a ‘vaccine-derived’ poliovirus type 2 (VDPV2).
VDPV is a strain of the weakened poliovirus, that was initially included in the oral polio vaccine, which has changed over time and behaves more like the “wild” or naturally-occurring virus.
This means it can be spread more easily to people who are unvaccinated and who come into contact with the faeces or coughs and sneezes of an infected person.
Dr Vanessa Saliba consultant epidemiologist at UKHSA said the risk to the public is extremely low.
She said: “Vaccine-derived poliovirus has the potential to spread, particularly in communities where vaccine uptake is lower.
“Most of the UK population will be protected from vaccination in childhood, but in some communities with low vaccine coverage, individuals may remain at risk.
“We are urgently investigating to better understand the extent of this transmission and the NHS has been asked to swiftly report any suspected cases to the UKHSA, though no cases have been reported or confirmed so far.”
Have you got a story for us? You can contact us here.
Follow us on Facebook, Twitter and Instagram to keep up with all the latest news.
To receive breaking news alerts or newsletters sign up here.
Check out our Watford crime and court Facebook page here.