EMBARGOED: Poliovirus detected in sewage from North and East London

• UKHSA investigation underway to ensure the public is protected
• Public urged to ensure their polio vaccines are up-to-date, especially parents of young children who may have missed an immunisation opportunity; but
• No associated cases of paralytic polio have been detected to date and the risk to the public assessed as low

 The UK Heath Security Agency (UKHSA), working with the Medicines & Healthcare products Regulatory Agency (MHRA), has found poliovirus in sewage samples collected from the London Beckton Sewage Treatment Works.

As part of routine surveillance, it is normal for 1 to 3 'vaccine-like' polioviruses to be detected each year in UK sewage samples but these have always been one-off findings that were not detected again. These previous detections occurred when an individual vaccinated overseas with the live oral polio vaccine (OPV) returned or travelled to the UK and briefly ‘shed’ traces of the vaccine-like poliovirus in their faeces.

Investigations are underway after several closely related viruses were found in sewage samples taken between February and May. The virus has continued to evolve and is now classified as a 'vaccine-derived' poliovirus type 2 (VDPV2), which on rare occasions can cause serious illness, such as paralysis, in people who are not fully vaccinated.

The detection of a VDPV2 suggests it is likely there has been some spread between closely linked individuals in North-East London and that they are now shedding the type 2 poliovirus strain in their faeces. The virus has only been detected in sewage samples and no associated cases of paralysis have been reported but investigations will aim to establish if any community transmission is occurring.

The last case of wild polio contracted in the UK was confirmed in 1984 and the UK was declared polio-free in 2003.

Dr Vanessa Saliba, Consultant Epidemiologist at UKHSA said:

“Vaccine-derived poliovirus is rare and the risk to the public overall is extremely low.

“Vaccine-derived poliovirus has the potential to spread, particularly in communities where vaccine uptake is lower. On rare occasions it can cause paralysis in people who are not fully vaccinated so if you or your child are not up to date with your polio vaccinations it’s important you contact your GP to catch up or if unsure check your red book. 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.”

Jane Clegg, Chief nurse for the NHS in London said:

“The majority of Londoners are fully protected against Polio and won’t need to take any further action, but the NHS will begin reaching out to parents of children aged under five in London who are not up-to-date with their Polio vaccinations to invite them to get protected.

“Meanwhile, parents can also check their child’s vaccination status in their Red Book and people should contact their GP Practice to book a vaccination should they or their child not be fully up-to-date.”

The UK is considered by the World Health Organization to be polio-free with low-risk for polio transmission due to the high level of vaccine coverage across the population. However, vaccine coverage for childhood vaccines has decreased nationally and especially in parts of London over the past few years so the UKHSA is urging people to check they are up to date with their vaccines.

Wastewater surveillance is being expanded to assess the extent of transmission and identify local areas for targeted action. Healthcare professionals have been alerted to these findings so they can promptly investigate and report anyone presenting with symptoms that could be polio, such as paralysis.

Ends

Notes to editors

The London Beckton Sewage Works is a sewage treatment plant covering a large catchment area across North and East London with a population close to 4 million.

The testing was conducted by the WHO Global Specialised Polio Laboratory located at the National Institute for Biological Standards and Control (NIBSC) which is part of the Medicines and Healthcare products Regulatory Agency (MHRA). The centre conducts routine environmental surveillance for wild type and vaccine-like polioviruses as part of the UK’s commitment to the WHO global polio eradication programme.

GPEI reporters guide provides recommendations on how journalists can report responsibly on polio outbreaks.

Live OPV is used in some countries around the world, particularly to respond to polio outbreaks. This vaccine generates gut immunity and for several weeks after vaccination people can shed the vaccine-virus in their feaces.

OPV has not been used in the UK since 2004.

Vaccine viruses can spread in under-vaccinated communities from person to person through poor hand hygiene and water and food contamination (and, less frequently, through coughs and sneezes).

During the spread the virus can mutate into a ‘vaccine-derived poliovirus’. This behaves more like naturally occurring ‘wild’ polio and may, on rare occasions, lead to cases of paralysis in unvaccinated individuals.

UKHSA’s national response has been established in line with National Polio Guidelines.

About Polio

Polio is a rare disabling and life-threatening disease caused by the poliovirus.

Polio is caused by a virus that spreads easily from person to person mainly through the faecal-oral route. It can be spread by poor hand hygiene (when an infected person does not properly wash their hands after using the toilet and then touching food/water that is eaten by others) and, less commonly, through coughing and sneezing. The virus multiplies in the intestine and infected people excrete large quantities of virus in their faeces. The virus can infect a person’s spinal cord, causing paralysis (weakness of parts of the body).

Most people with polio won't have any symptoms and will fight off the infection without even realising they were infected. A small number of people will experience a flu-like illness 3 to 21 days after they're infected.

Symptoms can include:

• a high temperature (fever) of 38C (100.4F) or above
• a sore throat
• a headache
• abdominal (tummy) pain
• aching muscles
• feeling and being sick

These symptoms will usually pass within about a week without any medical intervention.

In a small number of cases, between 1 in 100 to 1 in 1000 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, it can be life threatening.

If you or your child is experiencing unusual symptoms that could be the beginning of paralysis you should always seek medical advice immediately. Symptoms include rapid onset of weakness in a limb which will be flaccid (or floppy). The weakness most often involves the legs, but sometimes affects the muscles of the head and neck, or breathing.

After paralytic polio, movement will often slowly return over the next few weeks and months but many people are left with persistent problems. If you are experiencing these symptoms you should consult a health professional immediately.

About Polio vaccines

The best way to prevent polio is to make sure you and your child are up to date with your vaccinations. The vaccine is given as part of a combined jab to babies, toddlers and teenagers as part of the NHS routine childhood vaccination schedule.

It's given when your child is:

• 8, 12 and 16 weeks old as part of the 6-in-1 vaccine
• 3 years and 4 months old as part of the 4-in-1 (DTaP/IPV) pre-school booster
• 14 years old as part of the 3-in-1 (Td/IPV) teenage booster

You need to have all of these vaccinations to be fully vaccinated against polio.

If you are not up to date, you can have a polio vaccination at any point for free on the NHS.

You should also get vaccinated even if you've had polio before as the vaccine protects against three different types of poliovirus.