Polio is caused by a virus. In most cases it does not manifest clinically (subclinical infection) usually resolves by itself. This type of infection occurs in 95% cases.
Polio infection of its non-paralytic and paralytic varieties usually does not have a cure. Management usually involves control of symptoms while the infection runs its usual course.
Treatment of polio
Treatment outline of polio involves (1):
- Symptoms of fever, headache, back, and neck and muscle pain are relieved by using pain relievers and muscle relaxant medications. Usually NSAIDs like Ibuprofen, Diclofenac and Acetaminofen are preferred.
Aspirin is not used in children with viral infections for fear of Reye’s syndrome that causes severe irreversible liver damage.
Opioids like Morphine etc. are not prescribed as they may suppress breathing further leading to respiratory failure.
- For pain, spasm and stiffness in the muscles moist heat using warm towels and heating pads may be used.
- Patients who have difficulty breathing or have paralysis of respiratory muscles may need breathing support using artificial support like ventilators.
- Those with urinary tract infections need antibiotics. There may be problems in urinating due to difficulty in beginning urinating. This may lead to retention of urine.
Drugs like Bethanechol are prescribed to relieve urinary retention. Some patients may need placement of a urinary catheter to relieve the urine.
- There may be complications like pneumonia due to paralysis. This requires appropriate management with antibiotics.
Some patients may develop Cor pulmonale which is a form of heart failure that occur in the right side of the heart. Heart problems like myocarditis and high blood pressure may also be seen in some patients. These need appropriate therapy.
Due to prolonged immobility there may be loss of normal movement within the intestines leading to constipation. This can be treated with appropriate drugs. Kidney stones are also common in patients with prolonged paralysis.
- Patients with paralysis may benefit from physical therapy, exercises braces or corrective shoes. These may help recover muscle strength and function. Some patients may also need orthopaedic surgery.
- Outcome of polio infection depends on the severity of the infection. If the spinal cord and brain are not involved, which is the case more than 90% of the time, complete recovery is likely.
On the other hand involvement of the brain and spinal cord is a medical emergency and may lead to paralysis of respiration or death.
Lower or upper limb paralysis may persist as weakness or paralysis that leads to disability for life. Disability is more common than death. Lesions of the lower spinal cord lead to disability and those high up lead to respiratory paralysis.
Prevention of polio
Prevention of polio is one of the best approaches towards the disease. Paralytic polio has no cure and may lead to death and disability.
Prevention of polio involves (2-4):
- Maintenance of good hygiene to prevent transmission of the virus. This involves drinking clean water, regular hand washing and appropriate disposal of nasal and mucus secretions.
- Vaccines are of two types. One is the inactivated polio vaccine (IPV) and the other oral polio vaccine (OPV).
IPV vaccine for polio
IPV also called Salk vaccine, is injected in the leg or arm, depending on age. IPV is given to a child at age of 2, 4 and 6-18 months. A booster dose is needed at 4-6 years.
Adults usually do not need polio vaccine if they have been vaccinated as children. However, those who are travelling to a place where there is a polio outbreak, those working with samples of polio virus in a laboratory and those living in contact with a polio virus infected person may need to be vaccinated.
Pregnant women, those with a suppressed immunity and those with HIV require to be vaccinated with IPV. Adult regimen of vaccination is first dose at any time followed by second dose 1 to 2 months later and third dose 6 to 12 months after the second.
OPV vaccine for polio
OPV is also called Sabin vaccine. It contains live but much weakened polio virus given as oral drops.
It helps the receiver’s immune system to recognise the virus and create antibodies against it so that when they are faced with the actual infection they may be able to fight it.
Another benefit of OPV is that children vaccinated with the drops excrete the vaccine virus that is much weakened.
The contacts of the child who are not vaccinated receive the dose of the vaccine virus second hand from them. This contains the polio outbreaks and is important for eradication of polio.