Polio (Poliomyelitis)

Polio is a serious viral infection that mainly affects children under the age of five. Approximately one in 200 infections results in permanent paralysis and five to ten per cent of those cases are fatal. There hasn’t been a natural case of polio in the UK since 1984 but the disease is still found in other parts of the world.

Confirmed cases per country per year

Incubation period

7-21 days

Symptoms

High temperature, Sore throat, Headache, Abdominal pain, Stiff neck or back, Aching muscles, Feeling or being sick

Possible complications

Paralysis (temporary or permanent), Breathing difficulties, Death

About Polio

Polio is a serious viral infection that is spread by contaminated food or water and mainly affects children under the age of five. It emerged as a serious health threat to the UK in the middle of the 20th century, causing hundreds of deaths and paralysing thousands of children every year.

Thankfully, cases of polio fell dramatically with the introduction of the polio vaccine in the 1950s. The World Health Organisation declared Europe polio-free in June 2002, although the UK has had this status for considerably longer. The last case of paralysis recorded in the UK was in 2000 in someone who contracted polio from the then-used live vaccine (this is no longer offered in Britain).

Polio symptoms

Polio is still found in some parts of the world, which is why vaccination is recommended.

Most people with the illness don’t experience any symptoms and fight off the infection without ever knowing they were ill.

However, a small number of people with polio experience a flu-like illness that appears between three and 21 days after they were infected. In these cases, symptoms include a high temperature, sore throat, headache, abdominal (tummy) pain, aching muscles, and feeling and being sick. These symptoms usually pass within about a week.

Possible complications

In some cases, the polio virus attacks the nerves in the spine and the base of the brain. This can cause paralysis, usually in the legs, that develops over hours or days. The paralysis isn’t usually permanent and movement will often slowly return over a period of weeks or months.

One in 200 infections leads to irreversible paralysis. Among those paralysed, five to ten per cent die due to paralysis of the respiratory muscles used to breathe.

Polio FAQs

Polio is caused by one of three types of poliovirus and is often spread due to contact with infected faeces and poor handwashing. It can also be passed through eating or drinking contaminated food or water.

In some cases, polio is spread when an infected person coughs or sneezes infected droplets into the air. An infected person can also excrete the virus in their stool for several weeks. People are most contagious right before symptoms start and soon after they appear.

During the 1950s, there were approximately 8,000 cases of paralytic poliomyelitis each year. These numbers dropped rapidly after the widespread introduction of the polio vaccine.

The last case of natural polio infection acquired in the UK was in 1984. Between 1985 and 2002, a total of 40 cases of paralytic polio were reported in the UK. Thirty of these cases were vaccine-associated paralytic polio (VAPP), which was a risk of the oral vaccination in use at the time. Nowadays, this is no longer a risk in Britain as we use an inactive version of the virus in the vaccine.

Six other cases had wild virus infection acquired overseas; and in a further five cases, all occurring before 1993, the source of infection wasn’t known but the wild virus was not detected.

The World Health Organisation declared that Europe was polio-free in June 2002. Indeed, wild poliovirus has been eradicated in all continents except Asia, and as of 2020, Afghanistan and Pakistan are the only two countries where the disease is still classified as endemic.

Vaccinations will continue to be given to all children in the UK while there is still a risk that a case of wild poliovirus could enter the country. Also, the oral polio vaccine is still used in some other countries, which could potentially cause a new outbreak as a person can shed the virus.

FIND OUT EVERYTHING YOU NEED TO KNOW ABOUT POLIO VACCINATION HERE

We’re often asked by parents whether we offer “polio drops”, which is how people sometimes describe the oral polio vaccine (OPV) – this is when the polio vaccine is given as a few drops of liquid into the mouth (sometimes on a sugar cube).

As mentioned above, the OPV is no longer available in the UK because it has been linked to cases of vaccine-associated paralytic polio (VAPP).

The OPV vaccine is still used in some other parts of the world. There are continuing efforts to make it less likely to cause VAPP.

A doctor may recognise the symptoms of polio, such as neck and back stiffness, abnormal reflexes, and difficulty swallowing and breathing. To confirm the diagnosis, a sample of throat secretions, a stool sample or a sample of spinal fluid (via a lumbar puncture) is checked for poliovirus.

There isn’t a cure for polio, which is why prevention through vaccination is important. Treatment consists of helping to manage the symptoms of the illness. This could include pain relief, portable ventilators to help with breathing or moderate exercise/physiotherapy to prevent deformity or loss of muscle function.

In June 2022, the UK Health Security Agency confirmed that poliovirus had been detected in sewage samples collected from the London Beckton Sewage Treatment Works.

It’s important to keep this news in perspective. It’s normal for approximately one to three samples of poliovirus to be found in UK sewage every year. These samples come from people who have had the oral polio vaccine and are “shedding” traces of the vaccine in their faeces.

The June 2022 case was unusual because several of the samples were “closely related” rather than one-offs, suggesting that there had been some spread of the virus between closely linked individuals in North and East London who were shedding ‘vaccine-derived’ poliovirus type 2 (VDPV2).

So far there have not been any reports of polio-related paralysis. However, the UK Health Security Agency is urging everyone to check that they have been vaccinated against polio, especially children under the age of five.

Individual advice about protecting your child against polio

Need advice about vaccinating your child against polio? The BabyJabs clinicians are here to listen and answer your questions to help you decide.