People infected with polio in the UK are unlikely to be aware of it – but if it is allowed to spread it could eventually reach an unvaccinated child, an expert has warned.
Health chiefs are scrambling to find out where the poliovirus is circulating, with the UK Health Security Agency (UKHSA) today declaring a “national incident” after it was detected at sewage works in London.
The samples were found at London’s Beckton Sewage Works, which serves four million people in the capital.
Officials are desperate to narrow the area where the virus – which can cause paralysis – is spreading.
This afternoon, Nicholas Grassly, professor of vaccine epidemiology at Imperial College London, told The Mirror that it was crucial the virus didn’t take root.
He said: “Only one in a few hundred people is paralyzed by polio, even in the unvaccinated population.
“No cases of paralysis have been reported so far, but if the virus spreads it will eventually lead to paralysis in an unvaccinated child.
“The priority now is to identify where it is.”
Prof Grassly said at the moment officials had “no idea” how many people currently have the virus.
It has been detected in sewage several times since February, but Prof Grassly said he believes today’s announcement was made because experts are now confident it is spreading.
The last community outbreak in the UK was in the 1970s, but health officials insist the current risk to the population is low.
“What we can see from the effluent is that it has been detected multiple times and there is genetic diversity, suggesting there may have been local circulation.”
He continued: “Hopefully this goes away but there is a risk it will spread further.
“We don’t want it to reach children who aren’t vaccinated. While not overly worrying at this time, it is of sufficient concern for the UKHSA to conduct this briefing.”
dr Kathleen O’Reilly, associate professor of infectious disease statistics and an expert on polio eradication, said the detection in wastewater helped prevent the virus from spreading in Israel.
dr O’Reilly said, “These results suggest that there may be localized spread of poliovirus, most likely among individuals who are not up to date on polio vaccination.”
She continued: “The results come from sewage samples, as people infected with the poliovirus shed virus in their faeces, which can then be detected in sewage treatment plants.
(Getty Images/Science Photo Library RF)
“Effluent monitoring for polio and other pathogens has been extremely useful in detecting pathogen emergence and acting on those detections early to prevent disease and further spread. Surveillance in London, which identified a vaccine-derived poliovirus, is one such example.
“Another example comes from Israel in 2014, where the poliovirus was also detected in sewage samples and cases of polio were prevented by vaccination.”
Oral polio vaccines sold abroad contain a “weakened” form of the virus — weakened in a lab so it can’t cause disease.
These vaccine-derived forms of the virus persist in the stool and are occasionally detected in routine UK sewage testing conducted in London and Glasgow.
The oral vaccines differ from the polio injections sold in the UK, which contain a completely inactivated form of the virus.
AFP via Getty Images)
Prof David Heymann, Professor of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, said: “Vaccine-derived poliovirus is now present in many countries around the world.
“The virus results from a mutation of the Sabin virus, which is a live virus used to vaccinate against polio, and causes paralysis in some, although most infections are asymptomatic.
“The Sabin virus-based vaccine (oral polio vaccine) is now used only in countries that are in the active eradication phase of polio eradication – other countries have switched to an inactivated poliovirus vaccine that cannot mutate .
“The fact that it was found in UK sewage is a testament to the strength of the UKHSA’s surveillance programmes.
“Its presence in sewage serves as a reminder that polio eradication is not complete worldwide. The high coverage of inactivated polio vaccine in the UK will limit the spread of vaccine-derived polio and protect those who are vaccinated from polio-paralysis. ”
It has sparked calls to ensure people – especially children – have been vaccinated against polio.
dr David Elliman, consultant pediatrician at Great Ormond Street Hospital, said: “Parents sometimes ask why we continue to vaccinate when diseases are uncommon in the UK or polio has been eliminated.
“The answer is that although we are an island, we are not isolated from the rest of the world, meaning diseases could be brought in from abroad.
“The finding of vaccine-derived poliovirus in sewage proves this. Although uptake of polio vaccines in the UK is high, there are children who are unvaccinated and are therefore at risk of contracting polio if exposed to this virus.
“The risk is small but easily avoidable with the vaccine which kills in the UK and therefore cannot cause the disease. There is no upper age limit for the vaccine. Anyone who is not fully vaccinated against polio should seek advice from their health visitor or GP practice.”
The risk of transmission across the community is currently being determined.
Polio is an infectious disease caused by a virus that can spread from person to person and cause paralysis.
Early symptoms of polio in children and adults
According to the NHS, early warning signs can include:
- A high temperature
- Extreme tiredness (tiredness)
- nausea (vomiting)
- A stiff neck
- Muscle aches.
How polio spreads
The latest outbreak in London is said to have been caused by a person returning to the UK after being vaccinated against polio by mouth.
It remains unclear how widely the virus has spread, but it may be limited to a single household or extended family.
Polio is transmitted when an infected person’s stool (feces) comes in contact with another person’s mouth, either through contaminated water or through food.
Another way polio is spread is by oral transmission through the saliva of an infected person.
The potentially deadly disease can be prevented with a vaccine.
“Detection [is] underway to protect the public, who are being urged to ensure polio vaccines are up to date, particularly parents of young children who may have missed an opportunity to be vaccinated,” says the UK Health Security Agency.
“Vaccine-derived poliovirus has the potential to spread, particularly in communities where vaccine uptake is lower,” said Dr. Vanessa Saliba, Consulting Epidemiologist at the UKHSA.
She added: “On rare occasions, paralysis can occur in people who are not fully vaccinated. So if you or your child are not up to date on their polio vaccinations, it is important that you contact your GP to make up for it, or if you are unsure, check your red book.
“Most of the UK population will be protected from vaccination during childhood, but in some communities with low immunization coverage, individuals may remain at risk.”
Parents of children who are not up to date with their polio vaccination course are urged to make an appointment with their GP as soon as possible.
The UKHSA added that the risk to the general population was low.
https://www.mirror.co.uk/news/uk-news/polio-uk-fears-deadly-virus-27303512 Polio will paralyze an unvaccinated child if allowed to spread in the UK, an expert warns