Do you know?
Polio (poliomyelitis) mainly affects children under 5 years of age.
One in 200 infections leads to irreversible paralysis. Among those paralyzed, 5% to 10% die when their breathing muscles become immobilized.
Polio cases have decreased by over 99% since 1988, from an estimated 350 000 cases then, to 406 reported cases in 2013. The reduction is the result of the global effort to eradicate the disease.
In 2014, only 3 countries (Afghanistan, Nigeria and Pakistan) remain polio-endemic, down from more than 125 in 1988.
As long as a single child remains infected, children in all countries are at risk of contracting polio. Failure to eradicate polio from these last remaining strongholds could result in as many as 200 000 new cases every year, within 10 years, all over the world.
In most countries, the global effort has expanded capacities to tackle other infectious diseases by building effective surveillance and immunization systems.
Polio and its symptoms
What causes Polio?
Polio is a highly infectious disease caused by a virus. It invades the nervous system, and can cause total paralysis in a matter of hours. The virus is transmitted by person-to-person spread mainly through the faecal-oral route or, less frequently, by a common vehicle (e.g. contaminated water or food) and multiplies in the intestine. Initial symptoms are fever, fatigue, headache, vomiting, stiffness in the neck and pain in the limbs. One in 200 infections leads to irreversible paralysis (usually in the legs). Among those paralysed, 5% to 10% die when their breathing muscles become immobilized.
People most at risk
Polio mainly affects children under 5 years of age.
What are the signs and symptoms of Polio?
Polio can cause a wide range of symptoms that can have a serious effect on everyday life.
Fatigue is the most common symptom It can take many forms in people with the condition, including:
muscle fatigue – where your muscles feel very tired and heavy, particularly after physical activity
general fatigue – where you feel an overwhelming sense of physical exhaustion, as if you have not slept for days
mental fatigue – where you find it increasingly difficult to concentrate, have problems remembering things and make mistakes that you would not usually make
The fatigue experienced by people with polio is usually worse in the early afternoon and improves with rest or brief naps.
Increasing muscle weakness is another common symptom . It can be easy to confuse muscle weakness with muscle fatigue, but they are different.
Muscle weakness means that you are increasingly unable to use affected muscles, whether you feel fatigued or not. Weakness can occur in muscles that were previously affected by an active polio infection, as well as in muscles that were not previously affected.
There may also be associated shrinking of affected muscles, known as atrophy.
Muscle and joint pain
Muscle and joint pain are also common . Muscle pain is usually felt as a deep ache in the muscles or muscle cramps and spasms.
The pain is often worse after you have used the affected muscles. It can be particularly troublesome during the evening after a day’s activities.
Joint pain is similar to arthritis and consists of soreness, stiffness and a reduced range of movement.
As well as the common symptoms of Polio, several associated symptoms can arise from the combination of fatigue, muscle weakness and muscle and joint pain.
Because of the common symptoms mentioned above, most people with PPS become less physically active than they used to be.
This can often lead to weight gain and, in some cases, obesity. This in turn can make any fatigue, muscle weakness and pain worse.
As well as weight gain, the combination of fatigue, weakness and pain can lead to walking difficulties and increasing difficulty with mobility.
Many people with Polio will require a walking aid such as crutches or a cane at some stage, and some people may eventually need to use a wheelchair.
Sleep apnoea affects many people with PPS. It is a condition in which the muscles in your throat relax during sleep, which can lead to problems sleeping.
Once the muscles relax, the airway in your throat can narrow or become totally blocked. This interrupts the oxygen supply to your body, which triggers your brain to pull you out of deep sleep so that your airway can be reopened and you can breathe normally.
Weakness in the muscles you use for chewing and swallowing may lead to problems swallowing (dysphagia), such as choking or gagging when you try to swallow.
You may experience changes in your voice and speech, such as hoarseness, low volume or a nasal-sounding voice, particularly after you have been speaking for a while or when you are tired.
Swallowing problems are usually mild and progress very slowly. A speech and language therapist may be able to help.
Sensitivity to cold
Some people with Polio find that they become very sensitive to cold temperatures or a sudden drop in temperature as a result of poor blood supply.
Because of this intolerance to cold, people with Polio may need to wear extra layers of clothing to try to stay comfortable.
There is no cure for polio, it can only be prevented. Polio vaccine, given multiple times, can protect a child for life.