Further polivirus samples have been found in sewage in the London areas of Barnet, Brent, Camden, Enfield, Hackney, Haringey, Islington, and Waltham Forest.
The virus has also been found in lower concentrations in areas adjacent to the Beckton catchment area to the south - which is immediately below the Thames - and to the east of Beckton.
This comes after a national incident was declared by the UK Health Security Agency (UKHSA) in June after the virus that causes polio was also found in samples taken between February and May from the London Beckton Sewage Treatment Works, which serves around four million people in north and east London.
But what is polio, what are the symptoms and is there a vaccine?
Here’s what you need to know.
What is polio?
Polio is a serious infection that’s now very rare as it can be prevented with vaccination.
It was officially eradicated in the UK in 2003, but samples have now been found in London sewage.
Polio is caused by a virus that spreads easily when an infected person coughs or sneezes and it can also be caught from food or water that’s been in contact with the poo of someone who has the virus.
What are the symptoms of polio?
Most people who get polio do not have symptoms, but some people get mild, flu-like symptoms, such as:
- a high temperature
- extreme tiredness (fatigue)
- being sick (vomiting)
- a stiff neck
- muscle pain
These symptoms usually last up to 10 days.
Polio can also cause difficulty using your muscles (paralysis), usually in the legs, which can happen over hours or days, but this is rare and is not usually permanent.
Movement will slowly come back over the next few weeks or months.
However, it can be life threatening if the paralysis affects the muscles used for breathing.
You should ask for an urgent GP appointment or get help from NHS 111 if you have travelled to a country where polio is found and have polio symptoms.
What is the treatment for polio?
According to the NHS, treatment for polio will help your body fight off the infection and lower the risk of long-term problems.
It can include:
- bed rest in hospital
- help with breathing
- regular stretches and exercises to prevent problems with your muscles and joints
You may also need to have specialist help such as physiotherapy or surgery if you have any long-term problems caused by polio.
Is there a polio vaccine?
The best way to prevent polio is to make sure you and your child are up to date with your vaccinations, the NHS said.
You can ring your GP to check your polio vaccination status.
The polio vaccine is part of the NHS routine childhood vaccination schedule and is 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.
You can have a polio vaccination at any point if you’ve never had one before, even if you’re not travelling to a country with a risk of getting polio.
You should also get vaccinated even if you’ve had polio before as it protects against different types of polio.