Polio or Poliomyelitis is a life-long disabling disease caused by Poliovirus. Administering polio vaccine to children is inevitable to eradicate this disease.

Polio

PNS SHIFA

Online Consultation

Syed Intisar Hussain

Overview

Polio, short for poliomyelitis, is a life-threatening viral disease caused by poliovirus. It is easily transmitted from person to person, and the most severe symptom of this infection causes complete or partial paralysis<a href="#accordion">[8]</a>.

Polio has been around since ancient times, but with the help of the right vaccines and immunization solutions, most of the world is free of polio. Mass immunizations have helped people develop herd immunity and even now while cases still prevail in low-income countries, they are not lot in number. In 1988, a global initiative was taken for the eradication of the virus and the following regions are now completely polio-free<a href="#accordion">[13]</a>: 
&nbsp;

<ul>
	<li>Western Pacific</li>
	<li>The African region</li>
	<li>The Americas</li>
	<li>Europe</li>
	<li>South East Asia</li>
</ul>

This leaves only two countries that still have recent cases reported of poliomyelitis, i.e., Pakistan and Afghanistan. The lockdown affected the prevalence of polio cases in Afghanistan, with only 4 reported cases in 2021<a href="#accordion">[10]</a>. In Pakistan, a total of 22 cases were reported in 2020, all from Khyber Pakhtunkhwa. There was no report of any more cases in 2021. Balochistan reported one case of polio in 2021<a href="#accordion">[1]</a>. It is safe to say that with the help of mass immunization programs carried on by the government, Pakistan is on the road to becoming polio-free. 
&nbsp;

There are three types of polioviruses, and each requires its strain to be included in the vaccine formulation for its eradication despite being structurally similar. Today, only type 1 of the virus remains. Type 2 and 3 were completely eradicated from the world. The world was declared free from the type 2 poliovirus in September 2015, around 5 years after being type 2 polio-free since the last recorded case in 1999, in India<a href="#accordion">[2]</a>. The world was declared free of type 3 virus in October 2019, with the last reported case being in November 2012.

Type 1 on the other hand is still prevalent in Pakistan and Afghanistan with both countries carrying out programs of mass immunization for its eradication.&nbsp; 
&nbsp;

Signs And Symptoms

Poliomyelitis can be so mild that there are no visible symptoms, and even goes unnoticed. While in severe cases, it can cause death. The virus can affect people in different ways and is not always paralytic polio, also known as abortive polio. This type of polio often causes signs similar to the flu, including<a href="#accordion">[14]</a>:&nbsp;

<ul>
	<li>Sore throat</li>
	<li>Fever</li>
	<li>Vomiting</li>
	<li>Headache&nbsp;</li>
	<li>Fatigue</li>
	<li>Back pain</li>
	<li>Neck pain</li>
	<li>Stiffness or pain in the limbs</li>
	<li>Muscle weakness</li>
	<li>Numbness</li>
</ul>

Severe cases of polio are rare, but the initial symptoms are similar to that of non-paralytic polio. This may include loss of reflexes, muscle cramps or weakness, irregular breathing, flaccid paralysis and sometimes even death may occur.&nbsp; 
&nbsp;

Post-Polio Syndrome: Even after you have recovered from polio, some effects remain in your body after your recovery. This phenomenon is termed post-polio syndrome. PPS mainly targets nerves and muscles in patients<a href="#accordion">[4]</a>. These symptoms appear 30-40 years after suffering from polio and the symptoms include severe joint pain and weakness, muscle weakness, muscle atrophy, swallowing issues, sleep apnea, and decreased body tolerance for colder temperatures<a href="#accordion">[15]</a>.&nbsp; 
&nbsp;

Causes

Polio is easily spread through infected feces. Practice of poor hygiene like improper hand-washing or consuming contaminated food are the major factors of its transmission, but the virus can also be spread through sneezing, coughing or anything that suspends saliva droplets into air<a href="#accordion">[5]</a>.

The mechanism of the virus involves the entrance of it into the body through the mouth or the nose. The virus tends to multiply in the throat, and travel to the digestive and the respiratory system. It also tends to multiply in the intestines, and is easily spread to the different parts of the body by entering the bloodstream from the intestines.

This virus also travels up to the nervous system and exerts it effects, hindering the communication of the brain with the rest of the body<a href="#accordion">[9]</a>. The body&rsquo;s motor neurons in the spinal cord are the most affected part in cases of paralytic polio.&nbsp; 
&nbsp;

Diagnosis

In many cases, polio can be easily recognized by the symptoms, but several tests are prescribed to confirm the diagnosis<a href="#accordion">[14]</a>. These tests include:&nbsp; 
&nbsp;

<ul>
	<li>Physical Examination: A thorough physical examination is conducted which may involve the checking of your muscles, especially respiratory function to determine the virus&rsquo; effect on the spinal cord. Muscle reflexes are also tested along with the stiffness of the muscles and the movement of your neck or limbs<a href="#accordion">[12]</a>. 
	&nbsp;</li>
	<li>Virus Isolation And Detection: This is the most crucial part of the diagnosis of poliovirus. The virus is best isolated from stool specimens or a buccal swab. While isolation from blood or CSF is difficult, in some cases it is still performed. An average of 2 stool samples are collected from the patient, at least a day apart. These samples are ideally collected within 14 days after the onset of the symptoms<a href="#accordion">[7]</a>.&nbsp; 
	&nbsp;</li>
	<li>Cerebrospinal Fluid Examination: Cerebrospinal fluid is present in the brain and the spinal cord. The test is done with the help of a lumbar puncture with a thin long needle between the vertebrae. The obtained fluid is then tested for blood cells, especially the number of leukocytes and also proteins. However, a CSF examination is not as robust because these conditions can also occur due to other types of infection.&nbsp; 
	&nbsp;</li>
	<li>Oligonucleotide Mapping: Also known as fingerprinting, this process involves observing the genetic sequence of the isolated virus to determine if the virus originated from a vaccine, or if it is a wild type of virus. 
	&nbsp;</li>
	<li>Blood Test: It is the most common type of test carried out for polio diagnosis. The test detects the presence of antibodies against the poliovirus.&nbsp; 
	&nbsp;</li>
</ul>

Treatment

The approach taken for treating polio is symptoms-based i.e., they target the treatment of the symptoms to aid the body in fighting off the virus then the virus itself since there is no direct cure<a href="#accordion">[18]</a>.

The key to getting better faster and avoiding the worsening of the disease is the right care to support your body. Following are the steps suggested by healthcare practitioners for proper recovery from polio:

<ul>
	<li>Complete bed rest</li>
	<li>Isolation to stop further transmission</li>
	<li>In case of the occurrence of paralysis, passive moments are employed to avoid any physical deformity</li>
	<li>Use of positive pressure ventilator to aid in breathing</li>
	<li>Pain relievers&nbsp;</li>
	<li>Antibiotics in case of urinary tract infections</li>
	<li>Antispasmodics to ease muscle stiffness&nbsp;</li>
	<li>Pulmonary rehabilitation</li>
	<li>A mobility aid like a wheelchair or a stick</li>
	<li>A complete well-balanced nutrition 
	&nbsp;</li>
</ul>

<div>Apart from the paralysis and muscular atrophy, polio can do a lot more damage to the human body. Following are some of the complications that is often faced by polio patients:</div>

<ul>
	<li>Pharyngeal paralysis</li>
	<li>Myocarditis</li>
	<li><a href="https://www.merisehat.pk/disease/hypertension-57" target="_blank">Hypertension</a></li>
	<li>Post-polio syndrome</li>
	<li>Gastrointestinal hemorrhage</li>
	<li>Cardiovascular collapse</li>
	<li><a href="https://www.merisehat.pk/disease/osteoarthritis-64627" target="_blank">Joint pain</a></li>
	<li>Myalgia</li>
	<li>Atrophy</li>
	<li>Fatigue 
	&nbsp;</li>
</ul>

Only a small number of the total infected population develop paralysis. But several risk factors and common factors in the people who have suffered from paralytic poliomyelitis&nbsp;have been penned down after years of research,&nbsp;including:

<ul>
	<li>Removal of tonsils</li>
	<li>Not being immunized for poliovirus</li>
	<li>Children</li>
	<li>Polio&nbsp;</li>
	<li>Exposure during pregnancy</li>
	<li>Immunocompromised individuals</li>
	<li>I/M injections</li>
	<li>Excessive exercise</li>
	<li>Caretaking or coming in contact with a polio patient 
	&nbsp;</li>
</ul>

Prevention is better than treatment. Especially when it comes to polio, there are several vaccinations that have been developed over the years. There are two types of vaccines available: 
&nbsp;

<ul>
	<li>Inactivated Poliovirus Vaccine (IPV): Developed in 1955 by Dr. Jonas Salk, the vaccine is also known as the Salk vaccine. The composition of the vaccine involves denatured or killed strains of all three poliovirus types. Since it is not a live vaccine, there is no risk of developing vaccine-associated paralytic poliomyelitis. With enough evidence to back this claim, IPV triggers a good response with proper antibody formation and minimal side effects. The vaccine is to be administered intramuscularly or through the intra-dermal route. 
	IPV is one of the safest options out there for immunisation against poliovirus. However, it comes with two downsides. The very first being that despite the triggering of proper antibody formation throughout the body, the efficacy seems to be low in the intestine. This leaves the person exposed to any possible infection with the poliovirus that may be able to replicate in the intestine. Another issue is the production cost and the inconvenience of administration for mass immunisation. This type of vaccine is mostly used in developed nations<a href="#accordion">[19]</a>. 
	&nbsp;</li>
	<li>Oral Poliovirus Vaccine (OPV): Formulated with all three strains of live attenuated virus, this type of vaccine is administered with the target to trigger our body&rsquo;s immune response to the attack of wild poliovirus<a href="#accordion">[3]</a>.&nbsp;OPV is most commonly used in developing countries, especially in countries like Pakistan that are dealing with vaccine hesitancy on the issue of polio. In Pakistan, immunisation&nbsp;is absolutely crucial to become polio free. The biggest drawback of the OPV vaccine is that it may trigger an infection in some people, and even cause a paralytic infection in at least 1 out of 2.5 million administered doses. However, since the side effects are very rare, on average, it is recommended to get around 4 doses of the vaccine as a child. They should get one at the age of 2 months, second at the age of 4 months, third can be administered anywhere from 6-18 months of age, whereas the last dose can be given when the child is 4-6 years old for complete immunity<a href="#accordion">[6]</a>. The advantage of this type of vaccine is that it does not require to be administered by a healthcare professional or involve any syringes making it much easier for mass immunisation,&nbsp;which in case of Pakistan, is often carried out from door-to-door<a href="#accordion">[16]</a>. 
	&nbsp;</li>
</ul>

<ul>
	<li>With the recent pandemic having us leaving no stone unturned, several researchers of Kirov Medical University monitored the effect of bivalent OPV on COVID-19. The research concluded that vaccinated individuals had lesser occurrence of COVID, as compared to the placebo group that was not administered the vaccine<a href="#accordion">[17]</a>.</li>
	<li>Only recently the UK was found to have its first likely outbreak of polio in over 40 years. Despite there being no actual outbreak, close examination of the sewage water of London led the scientists to find strains of poliovirus. However, the general threat from it is very low since most of the population of the UK is fully immunized against the virus<a href="#accordion">[11]</a>. 
	&nbsp;</li>
</ul>

Key Points

<ul>
	<li>Polio is a very old disease that has left countless people paralyzed. It has been eradicated from several regions of the world, but the disease still prevails in Pakistan and Afghanistan.</li>
	<li>There are a total of three types of poliovirus strains. Luckily, type 2 and type 3 are declared eradicated from the world, but Pakistan and Afghanistan still suffer from the infections of type 1.</li>
	<li>In most cases, polio is contracted through unhygienic means and practices involving the handling of stool, improper hand washing, and saliva exchange through droplets or cutlery.</li>
	<li>There are several traditional ways to diagnose the disease with the stool sample culture being the best method.</li>
	<li>There is no cure for polio. The only therapeutic approach is to provide symptomatic relief.</li>
	<li>While not all types of polio may leave you paralyzed, you can suffer post-polio syndrome that occurs decades after you have had polio and tends to cause muscle weakness, joint pain, atrophy, etc.</li>
	<li>There are two types of vaccines available namely IPV, which is administered through the traditional means by a sterile needle with the help of a healthcare practitioner, and OPV which can be administered orally and is the one that is commonly administered in Pakistan.</li>
	<li>Please note that poliomyelitis is a notification priority disease, and must be reported immediately to the relevant healthcare authorities 
	&nbsp;</li>
</ul>

[1] Babakhel, Z., 2022. Pakistan reports second polio case of 2022. [Online]

[2] Prevention, C. f. D. C. a., 2020. U.S. National Authority for Containment of Poliovirus. [Online]

[3] World Health Organization, n.d. Poliomyelitis. [Online]

[4] Cedars Sinai, n.d. Polio (Poliomyelitis). [Online]

[5] Cedars Sinai, n.d. Post-Polio Syndrome. [Online]

[6] Centers for Disease Control and Prevention, 2018. Vaccines and Preventable Diseases. [Online]

[7] Centers for Disease Control and Prevention, 2021. Gloabal Immunization - Diagnostic Methods. [Online]

[8] Centers for Disease Control and Prevention, 2021. What is Polio. [Online]

[9] Cleveland Clinic, 2021. Polio. [Online]

[10] Dawi, A., 2022. Will Afghanistan be Polio-Free in 2022?. [Online]

[11] Doucleff, M., 2022. Polio is found in the U.K. for the first time in nearly 40 years. Here's what it means. [Online]

[12] Dr. Ananya Mandal, M., 2019. Diagnosis of Polio. [Online]

[13] Healthline, 2018. Polio. [Online]

[14] Mayo Clinic, 2020. Polio. [Online]

[15] Mayo Clinic, 2022. Post-polio Syndrome. [Online]

[17] Nadezhda V. Yagovkina, L. M. Z. K. A. S. A. A. T. L. I. K. I. V. G. A. K. K. Y. Y. I. A. A. K. A. N. P. A. A. S. E. Y. S., 2022. Vaccination With Oral Polio Vaccine Reduces COVID-19 Incidence. Vaccination With Oral Polio Vaccine Reduces COVID-19 Incidence, Volume 13.