Poliomyelitis is an acute, highly infectious viral disease that affects the nerve and can lead to partial or total paralysis causing irreversible neurological damage.
The worldwide polio immunization program has allowed to eradicate the virus in most parts of the world, but the disease remains endemic in Afghanistan, Nigeria and Pakistan, and outbreaks have been reported in Somalia, Kenya and Syria.
Polio is caused by poliovirus, a pathogenic microorganism transmitted only between humans via fecal-oral route or by contaminated food or drinks that have been in contact with infected mucus, saliva or phlegm.
Initial symptoms include fever, weakenss, vomit, neck stiffness and pain in the limbs.
There are different forms of polio:
- Mild polio: also known as minor or abortive poliomyelitis, this form may be asymptomatic or cause generic flu-like symptoms.
- Greater or paralytic poliomyelitis is the most severe form and occurs in about 10% of cases. The initial symptoms are easily confused with those of a common flu, but worsen after about ten days. The patient complains of severe pain and muscle spasms, loss of reflexes and skin sensitivity, flaccid paralysis and inability to walk. Generally only the lower limbs are involved, though also muscles of the throat, neck, chest and abdomen may be compromised; there is a respiratory failure risk if the poliovirus reaches the spinal cord nerves that control thorax muscles.
A trail of invalidating symptoms known as Post Polio Syndrome (PPS) may follow the recovery from polio for a long time (more than 30 years). Among the most common symptoms there is general fatigue, sleep apnoea, muscle atrophy and joint weakness, difficulties breathing and swallowing, poor tolerance to the cold.
Cures and Therapy
At the present moment there is not a cure for polio, therefore action is focused towards prevention, immunization and symptom relief.
The therapy of paralytic form includes:
- Physical therapy to minimize muscle damage and slow the paralysis progression.
- Invasive mechanical ventilation via tracheotomy when polio affects respiratory muscles.