It is the first time a wild case of polio has been discovered on British soil since 1984.

Is poliomyelitis back? The British Health Security Agency (UKHSA) warns on the discovery of presence of the virus in London’s sewage.

If this happens one to three times a year, as the microdose of virus present in vaccines often ends up in the stool and therefore in sewage, the UKHSA finding suggests a contamination between humans having given rise to a mutation, polio “derived from a vaccine” behaving like wild polio.

“The detection of a VDPV2 suggests that it is likely that there has been some spread between closely related individuals in north and east London and that they are now shedding the poliovirus type 2 strain in their faeces,” says the UKHSA.

Parents told to make sure children’s polio vaccinations are up to date after number of virus samples found in London sewage https://t.co/7ePU6CZbhi

— BBC Breaking News (@BBCBreaking) June 22, 2022

No wild cases since 1984

The health agency therefore invites the British to check that their children are indeed vaccinated against the virus. They are indeed the ones who are most at risk of poliomyelitis, and are most at risk of paralysis, the main symptom of the disease.

No cases of wild polio had been detected in Britain since 1984 and the country declared itself free of any cases in 2003. The virus caused several outbreaks around the world, mainly in the early 20e century.

The only countries in which it still circulates in the wild are Afghanistan and Pakistan.