North East sewage sites to be tested for polio after virus found in London

Water samples will be tested across the North East. Credit: PA

Sewage checks will be taking place in the North East to see if the polio virus is spreading to the region.

The UK Health Security Agency (UKHSA) said it is carrying out checks on North Tyneside, and in Newcastle and Gateshead, along with a number of other sites across the country.

According to UKHSA, it is happening "on a precautionary basis to determine whether the virus is spreading to other areas".

Samples of polio virus were collected from the London Beckton Sewage Treatment Works, prompting the agency to expand its surveillance outside of the capital.

Polio: What we know so far

What is polio?

Polio is a contagious virus that can be transmitted through coughs and sneezes, but also through food, water or objects that have been in contact with the faeces of someone infected with it.It can live in an infected person's throat for weeks without them suffering any symptoms.

Around 70% of people who have polio have no symptoms.

The last confirmed case of polio in the UK was in 1984 and it was declared eradicated in 2003.

In most cases it appears like the flu with mild symptoms, but in rare instances - more than one in 100 - it can affect the nerves in your spine and brain and cause paralysis.

This paralysis is usually in the legs and normally lasts a few weeks or months.

But it can be life-threatening if the paralysis affects the muscles in your neck that help with breathing.

For those who do suffer some form of paralysis, around 2 to 5% of children and 15 to 30% of adults die.

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What has been discovered in the UK?

The UKHSA, working with the Medicines and Healthcare products Regulatory Agency (MHRA), 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.

Since then the virus has been found in: Barnet; Brent; Camden; Enfield; Hackney; Haringey; Islington and Waltham Forest in London.

While it is normal for the virus to be picked up as isolated cases and not detected again, experts have raised the alarm after several genetically-linked viruses were found in samples between February and May 2022.

The strain of polio is not the natural "wild" strain, but instead, it is a weaker form of the virus that is included in the oral vaccination.

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How did polio come back to the UK?

It is believed someone who received the oral vaccination brought the weakened case to the UK from abroad and then shed traces of it in their faeces.

However, this weakened polio has since evolved into ‘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 spread more easily to people who are unvaccinated and who come into contact with the faeces or coughs and sneezes of an infected person.The UKHSA is working on the theory that a person vaccinated abroad with the polio vaccine – possibly in Afghanistan, Pakistan or Nigeria – entered the UK early in 2022 and was shedding the virus.That person has now passed it onto other, closely linked individuals in north-east London, who in turn are shedding the virus into their faeces.

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Is there anything to worry about?

For the vast majority of the UK, there is nothing to worry about. All children in the UK have been offered the polio vaccine for decades.

The virus has not yet been found outside of London.

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Someone suffering from polio induced paralysis. Credit: AP

Dr Vanessa Saliba, consultant epidemiologist at UKHSA, said: "We are now expanding the sewage sampling nationally to areas that are at highest risk of new poliovirus importations and areas most likely to see spread of poliovirus from London.

"We are in touch with public health colleagues in these areas and will work closely with local areas as the need arises."

Parents are also being encouraged to check that their children are fully vaccinated in order to provide them with full protection. Credit: AP

Sewage sampling is taking place in Birmingham, Blackburn with Darwen, Bradford, Brighton and Hove, City of Bristol, Bury, Castle Point, Leeds, Leicester, Liverpool, Luton, Manchester, North Tyneside, Newcastle upon Tyne, Gateshead, Nottingham, Preston, Salford, Sheffield and Watford.

The UKHSA has said that the sewage sampling strategy will continue to be reviewed as new evidence emerges.

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