Poliomyelitis (polio) is a highly infectious disease caused by the poliovirus, an enterovirus from the Picornaviridae family.^1,2 It is extremely contagious and primarily spreads via the faecal-oral route, when faecal matter is ingested through contaminated hands or food. Less commonly, it may spread via a common vehicle, such as contaminated food or water. It can also enter through ingestion of respiratory droplets from an infected person.^3,7

Following ingestion, the virus replicates in the mucosal lining of the gastrointestinal tract, particularly targeting the tonsils and Peyer’s patches. From there, it spreads to deep cervical and mesenteric lymph nodes before entering the bloodstream (viremia). Once effective viremia is established, the virus can disseminate to the central nervous system (CNS), where it replicates within neurons, especially motor neurons in the anterior horn of the spinal cord and brainstem.^3,8,10

The poliovirus accesses the CNS either by crossing the blood-brain barrier or travelling along peripheral nerves. In most individuals, the infection is asymptomatic or results in mild, flu-like symptoms, with recovery occurring within a few days. Symptoms usually appear 7 to 14 days after exposure.^3,10 However, in about 1 in 200 infections, the virus destroys motor neurons, leading to flaccid paralysis, most commonly affecting the legs. More severe forms, such as bulbar polio, impair respiratory and swallowing functions, with a 5–10% mortality rate due to respiratory failure.^7,10  

There are three antigenically distinct serotypes of poliovirus: PV1, PV2, and PV3. Immunity to one serotype does not confer protection against the others, requiring the immune system to generate separate antibodies for each.²

History of polio

Poliomyelitis, known since ancient times, became a major public health issue in the late 19th century, causing widespread paralysis, especially in children. The first clinical description was given by Michael Underwood in 1789, and it was identified as a distinct disease by Jakob Heine in 1840.⁴ Major scientific advances followed: Dr. Ivar Wickman classified polio forms in 1907 and 1908, and Karl Landsteiner and Erwin Popper discovered its viral cause. The "iron lung" was developed in 1928 to help paralysed patients breathe. In 1931, three types of poliovirus were identified.⁶

The fight against polio advanced with the development of vaccines: Jonas Salk's injectable vaccine (IPV) in 1955 and Albert Sabin's oral vaccine (OPV) in 1961.² The UK adopted OPV in 1962 and saw its last natural polio case in 1984.¹ By 1988, polio was eliminated in most developed countries.⁷ That same year, the Global Polio Eradication Initiative began, leading to a 99.9% reduction in cases.⁶ Over 2.5 billion children have since been vaccinated. As of now, polio remains endemic only in Afghanistan and Pakistan.⁵

Pathogenesis

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Clinical features

Approximately 70% of polio infections are asymptomatic, yet individuals can still spread the virus via secretions and stool.⁹ About 25% experience mild, flu-like symptoms that resolve within a few days, while less than 1% develop paralytic polio, characterised by muscle weakness or paralysis.⁹ Paralytic polio has spinal, bulbar, and bulbospinal types, with a fatality rate of 2-5% in children and up to 75% when bulbar involvement occurs, primarily due to respiratory muscle paralysis.²

Nonparalytic symptoms generally appear within 3-6 days, and paralysis within 7-21 days post-infection.² Adults who had paralytic polio may later develop post-polio syndrome (PPS), an irreversible, noninfectious condition marked by progressive muscle weakness and joint pain in affected areas, emerging 15-40 years after the initial infection.⁸ Approximately 25-40% of polio survivors may develop PPS.⁸ PPS is marked by a gradual, irreversible decline in muscle strength, particularly affecting the muscle groups originally impacted by the polio infection.⁸ Additional common symptoms include muscle and joint pain.⁸

While polio typically affects children under five, unvaccinated people of all ages are at risk. Although there is no cure, the polio vaccine offers lasting protection.⁷

Long-term rehabilitation and support needs for individuals recovering from polio

Supportive care is vital in managing acute poliomyelitis, focusing on symptom relief, infection prevention, and mechanical ventilation for respiratory paralysis. Physiotherapy may involve splints to reduce pain and prevent deformities.¹⁰ Post-acute rehabilitation emphasises exercise, counselling, and education for recovery, with orthopaedic surgery sometimes needed to improve mobility and address deformities as patients age.¹⁰ Long-term rehabilitation aims to enhance independence, mobility, and quality of life for polio survivors, which are as follows: 

Exercise and physical therapy

For individuals with muscle weakness, stretching and range-of-motion exercises are crucial for preventing stiffness and maintaining function, especially in the chest and abdomen for breathing support, as well as flexibility in the hips and knees for walking. Low-impact aerobic exercises like swimming enhance cardiovascular endurance without straining joints, while painful activities should be avoided. A tailored approach to strength training, focusing on endurance rather than vigorous exercises, is recommended. To manage fatigue, individuals should break exercise into shorter sessions and gradually increase frequency, ensuring a balance to avoid excess or insufficient activity. Consulting a knowledgeable healthcare provider is essential for customising a therapy plan based on individual strengths and limitations, especially if they have conditions like heart disease.^8,13

Aquatic therapy

Aquatic therapy provides significant benefits for polio survivors by offering a low-gravity environment that facilitates various exercises, including range-of-motion, strength-building, low-impact aerobic routines, stretching, and swimming. It has been shown to improve strength and reduce pain. Pool accessibility and safety are essential, with water temperatures ideally between 90-92°F. Survivors should start with mild routines to avoid overexertion and gradually increase intensity as stamina improves, using adaptive equipment and modified techniques to maximise the benefits of aquatic therapy.13

Orthotics support and mobility aids

Well-fitted orthotic devices are essential for polio survivors, enhancing biomechanical efficiency and conserving energy. Supportive devices like long-leg braces for knee instability, short leg braces for "foot drop," and hand splints for wrist weakness are crucial for compensating muscle weakness, alleviating pain, improving stability, and protecting and stabilising joints. Custom-made orthotics generally provide better support than off-the-shelf options, and regular adjustments are necessary for comfort. Proper maintenance of the orthotics, including inspections and cleaning, is vital for maximising functionality and enhancing the independence of polio survivors.¹³

Pain management

Polio rehabilitation can take years and often involves managing chronic pain, especially in those with post-polio syndrome (PPS), where pain may persist for up to 20 years.¹⁵ Common pain areas include the shoulders, lower back, legs, hips, knees, and wrists. This pain can severely affect daily life, including sleep, mobility, work, and recreation.¹⁵ Effective management requires a thorough medical evaluation, typically revealing issues from muscle, tendon, or joint overuse.¹⁵ Treatment may include gentle stretching, heat, massage, physical therapy, braces, adaptive aids, and energy conservation.¹⁵ Medications like NSAIDs can help, but should be used cautiously long-term. In severe cases, epidural steroid injections may provide temporary relief. A comprehensive, individualised approach is essential for managing pain in polio survivors.¹⁵

Surgical interventions

Orthopaedic surgery may be necessary to facilitate walking and address potential deformities that can develop over time. Surgical options include releasing joint contractures, correcting muscle imbalances to prevent deformities, or addressing existing deformities directly. Surgical intervention might be needed in cases such as a torn rotator cuff tendon due to extensive arm use for mobility, foot deformities that lead to instability and increased fall risk, or joint replacements in the hip and knee of the stronger leg when they become worn. Patients must inform all healthcare providers about their polio history to ensure tailored care during treatment.¹³

Breathing and sleep problems in polio survivors

Polio survivors, particularly those with post-polio syndrome (PPS), need careful evaluation and management of respiratory and sleep issues due to weakened respiratory muscles. As they age, respiratory function often declines, making pulmonary function tests (PFTs) essential, especially before surgeries for those with a history of using iron lungs. Polio survivors may experience obstructive sleep apnea (OSA), central sleep apnea (CSA), a mix of both OSA and CSA, and/or issues with hypoventilation, typically treated with CPAP or BiPAP. Regular testing is crucial, and effective management may involve nocturnal ventilation or bronchodilators.¹⁴

Speech therapy

Speech therapy is crucial for polio survivors experiencing new swallowing difficulties and issues with vocal endurance. Consultation with a speech therapist can help manage dysphagia and dysphonia, thereby preventing malnutrition and ensuring adequate nutritional intake.¹³ 

Psychological support

Self-help strategies can effectively manage anxiety for individuals with post-polio syndrome (PPS). Mind-body practices like meditation, relaxation exercises, gentle yoga, and tai chi help calm the nervous system, while grounding techniques can aid during panic attacks. Family, friends, and peer group support, along with effective communication with healthcare providers, enhance quality of life.¹³

Disability-friendly workplace support for polio survivors

For many polio survivors, employment is essential for financial security, health insurance, and a sense of purpose, but work demands can strain fatigued muscles and exacerbate cognitive challenges. Regular physical assessments can help identify safe work tasks, as survivors may require longer recovery times from illness or injury. Lifestyle changes and workplace accommodations, such as seeking help with specific tasks, using ventilators during breaks, securing closer parking, or utilising specialised transportation, can help delay early retirement.¹³

Post-polio syndrome (PPS) management

Post-Polio Syndrome (PPS) management focuses on symptom relief and quality of life enhancement, as no targeted treatments exist. Key strategies include lifestyle modifications, pain management, and physical therapy. Annual check-ups and neuromuscular evaluations are recommended for symptomatic survivors, with family support being crucial for treatment adherence.^10,11,12

Summary

Long-term rehabilitation for polio survivors, particularly those with PPS, is vital for enhancing quality of life. A comprehensive approach includes physical rehabilitation, muscle strengthening, respiratory management, and the use of assistive devices. Regular evaluations and personalised exercise programs provide essential emotional backing, enabling individuals to cope with the effects of polio and maintain independence. Ultimately, a holistic strategy that integrates medical care with emotional and social support empowers polio survivors to lead fulfilling lives.