Acute Poliomyelitis

Acute poliomyelitis is an acute infection disease caused by the poliovirus, which affects the central nervous system, particularly the motor neurons in the spinal cord. Disease, although often asymptomatic or associated with mild symptoms, can in some cases lead to permanent paralysis and even death. Poliomyelitis is also known as infantile paralysis and causes significant morbidity, especially in children. Thanks to global vaccination campaigns led by the World Health Organization (WHO), poliomyelitis has been largely brought under control.

Etiology and Epidemiology of Acute Poliomyelitis

Poliomyelitis is caused by the poliovirus, which belongs to the Enterovirus genus (types 1, 2, and 3). The poliovirus spreads via the fecal-oral route (through contaminated water water or food). Virus, after entering the body through the mouth, replicates in the intestines and spreads via the lymphatic system. Rarely, the virus reaches the central nervous system, destroying motor neurons and causing paralysis.

Poliomyelitis is most common in areas with poor hygiene and low vaccination rates. Thanks to the WHO’s Global Polio Eradication Initiative, wild poliovirus types 2 and 3 have been eradicated. However, type 1 poliovirus remains endemic in certain regions of still Afghanistan and Pakistan like. Additionally, vaccine-derived poliovirus (VDPV) cases are rarely observed.

Clinical Features and Symptoms

Poliomyelitis infections can manifest clinically in four distinct forms:

1. Asymptomatic Infection

Approximately 90–95% of infected individuals show no symptoms. These individuals can still transmit the virus to others.

2. Abortive Poliomyelitis

This form is characterized by mild and nonspecific symptoms:

• Fever
• Headache
• Sore throat
• Vomiting
• Fatigue

This form does not affect the central nervous system and typically resolves spontaneously within a few day.

3. Non-paralytic Poliomyelitis

In addition to symptoms similar to abortive poliomyelitis, signs of meningitis are present:

• Neck stiffness
• Back pain
• Muscle spasms

No paralysis occurs in this form, and patients generally recover completely.

4. Paralytic Poliomyelitis

This is the most severe form of poliomyelitis and occurs in 0.1–1% of infected individuals. Symptoms include:

Initial phase: Fire, head pain and chest pain.

Paralytic phase: Sudden onset of asymmetric paralysis (usually in the legs). The paralysis is flaccid (limp) and reflexes are absent.

Recovery phase: Some paralyzed muscles may recover, but permanent weakness and atrophy can occur.

If paralytic poliomyelitis affects respiratory muscles, it can lead to respiratory failure and death.

Diagnostic Methods

The diagnosis of poliomyelitis is based on clinical findings and laboratory tests. The following methods are used:

Virus isolation: Detection of poliovirus in stool, throat swab, or brain cerebrospinal fluid (CSF) samples.

Polymerase Chain Chain Reaction (PCR): Used to detect poliovirus RNA.

Serological tests: Detection of antibodies against poliovirus in the blood.

Treatment Approaches

There is no specific antiviral treatment for poliomyelitis. Treatment consists of supportive and symptomatic measures:

Supportive Care

Respiratory support: Mechanical ventilation may be required if respiratory muscles are affected.

Physical therapy: Applied to rehabilitate paralyzed muscles and prevent muscle atrophy.

Pain management: Analgesics and muscle relaxants are used.

Management of Complications

POST-polio syndrome: Management of symptoms such as muscle weakness and fatigue that appear years after the initial infection.

Orthopedic interventions: Surgical procedures may be necessary to correct muscle contractures and deformities.

Prevention and Vaccination

The most effective way to prevent poliomyelitis is through vaccination. Two types of polio vaccines are available:

Oral Polio Vaccine (OPV)

Contains live attenuated virus and provides intestinal immunity. However, it can rarely cause vaccine-associated paralytic poliomyelitis (VAPP).

Inactivated Polio Vaccine (IPV)

Contains inactivated virus and is administered via Dead injection. It is safe and effective.

The WHO recommends the combined use of OPV and IPV in a combination schedule for polio eradication.