For Physicians
Sign Up 0    

Poliomyelitis (Polio)

Overview

Poliomyelitis, commonly known as polio, is a contagious viral infection that targets your nervous system. Young children below the age of 5 years are most likely to be affected by this disease. In its most severe form, polio can lead to nerve injury, paralysis, and breathing difficulties. If it is left untreated, it may prove fatal. Efforts have been made to eradicate poliovirus worldwide, but it still exists in certain regions. Vaccine against this disease is the best way to prevent poliomyelitis. 

Causes

Poliomyelitis is caused by poliovirus, which is a highly contagious virus. It can transmit from one infected person to another through fecal-oral contamination. People living in areas with reduced access to toilets or proper sanitation can contract this disease by drinking contaminated water. The virus is so contagious that it can easily transmit from an infected person to those living with the patient. Less common mode of transmission is through coughing or sneezing. Even people who carry the virus but do not have any symptoms are still capable of transmitting this virus to others. 

Risk Factors And Epidemiology

Polio targets young children, usually those below the age of 5 years. Adults that can be affected by polio include pregnant women, HIV-positive individuals, and people with weakened immune systems. If you are a frequent traveler, you may get exposed to poliovirus if you travel to an area with recent polio outbreak. The risk is higher if you are unvaccinated for poliovirus. Living with or taking care of someone with polio infection can also put your health at risk. Drinking contaminated water from places with active polio cases can spread the infection.

After the advent of the polio vaccine in 1953, the cases of polio have been eradicated from the United States by 1979. However, polio still exists in Afghanistan, Pakistan and Nigeria. There is no gender predilection for this infection. 

Signs And Symptoms

Based on the severity of signs and symptoms, polio can be divided into three categories. The first category is nonparalytic polio, in which the person carries poliovirus but only develops mild symptoms of a viral infection. These symptoms include fever, headache, sore throat, vomiting, fatigue, neck and back pain, stiffness, and muscle weakness.

The second category is called paralytic polio which leads to paralysis of the spinal cord, brainstem, or both. During the initial stage, the symptoms resemble nonparalytic polio, but after a week, neurological symptoms develop. These include loss of reflexes, severe spasms, muscle pain, floppy limbs, sudden paralysis, and deformation of limbs. Paralysis may be temporary or permanent. Permanent paralysis occurs in less than 1% of cases.

The third category is post-polio syndrome. This occurs when poliovirus returns years later after you have recovered from it once. Common symptoms include muscle pain, joint weakness, fatigue, muscle atrophy, difficulty breathing, sleep apnea, cold intolerance, difficulty concentrating, and depression. This can occur 15 to 40 years later after a polio infection. 

Diagnosis

Polio is diagnosed on the basis of clinical presentation in most cases. If you are an adult, your doctor will also require your recent medical and travel history. Your doctor will perform a physical examination to check your reflexes, muscle strength, and movement of your limbs. For an accurate diagnosis, a sample is taken from your throat, stool, or cerebrospinal fluid to check for the presence of poliovirus. 

Differential Diagnosis

Nonparalytic polio must be differentiated from other infections that present with similar symptoms. These include certain bacterial and viral infections or inflammatory diseases that may cause sore throat, fever, headaches, and muscle weakness. Some examples include influenza, common cold, mumps, etc. Paralytic polio should be differentiated from medical conditions that present with muscle weakness or paralysis. These include encephalitis, transverse myelitis, West Nile virus infection, Guillian-Barre syndrome, etc. 

Treatment

There is no absolute cure for polio. Treatment options are only available to relieve symptoms while the infection is still present. Supportive measures that can help with the symptoms include bed rest, use of medications, mechanical ventilation for better breathing, and heating pads to ease muscle spasms. Use of corrective braces and physical therapy can help with walking and muscle pain. If severe breathing issues present, pulmonary rehabilitation can help prove lung functions.

Painkillers can be given for pain and muscle aches, antibiotics for urinary tract infections, and antispasmodic drugs to reduce muscle spasms. All these medications can only provide symptomatic relief but cannot cure the disease. 

Prognosis

Patients with nonparalytic polio often have a complete recovery. Paralytic polio can cause temporary or permanent nerve damage, which can cause paralysis. The mortality rate is higher in individuals who develop paralysis of the respiratory muscles. 

Prevention

The best way to prevent polio is the polio vaccine. Newborn children in the United States receive four shots of polio vaccine at the ages of 2 months, 4 months, between 6 and 18 months, and between 4 to 6 years, respectively. The vaccine contains inactivated poliovirus, which is safe to be administered to children. If you are an adult planning to travel to a part of the world with active polio cases, you should have a booster dose beforehand. If you are unvaccinated or unclear about your vaccination status, it is recommended to get primary polio vaccination shots. The vaccine may cause an allergic reaction in some individuals, which can be managed by immediate medical attention.

Our clinical experts continually monitor the health and medical content posted on CURA4U, and we update our blogs and articles when new information becomes available. Last reviewed by Dr.Saad Zia on May 27, 2023.

 

References

Poliomyelitis (polio) (who.int)

https://www.who.int/health-topics/poliomyelitis#tab=tab_1

What is Polio? (cdc.gov)

https://www.cdc.gov/polio/what-is-polio/index.htm#:~:text=Polio%2C%20or%20poliomyelitis%2C%20is%20a,move%20parts%20of%20the%20body).

-->