Polio and World Polio Day

Polio and World Polio Day

Dr. Syed Sabahat Asharaf , Dr Bilal A Bhat

Polio (also known as poliomyelitis and infantile paralysis) is an infectious disease that is caused by viruses and may result in a wide range of symptoms in patients. Symptoms can range from a non-paralytic flu-like infection to total paralysis that can occur within a few hours. Children younger than 5 years old are more likely to contract the virus than any other group. According to the World Health Organization (WHO), 1 in 200 polio infections will result in permanent paralysis. The history of polio dates back about 6,000 years. Egyptian mummies have been found with withered and malformed limbs that likely occurred because of polio infection. In 1789, the first description of polio was recorded, and in 1834, the first documented epidemic occurred on the island of St. Helena. In 1855, Dr. Guillaume Benjamin Amand Duchenne showed polio involved the anterior horn cells (nerve cells) of the spinal cord. Landsteiner and Popper discovered the virus in 1908. The Iron lung was developed in the late 1920s to help some polio survivors with polio breathe. One of the most famous people who had polio was U.S. President Franklin D. Roosevelt (1882-1945).
The polio virus was first cultivated in tissue culture (1949), and in 1951, the three types of poliovirus were isolated and identified. During the mid-1950’s (1954), the first large-scale trial of the vaccine developed by Dr. Jonas Salk (dead virus vaccine) was administered by injection, and in 1958, Dr. Albert Sabin’s vaccine (live attenuated virus) was administered as an oral vaccine. In 2000, the U.S. switched to using inactivated polio vaccine by injection. Other countries still may use the oral poliovirus vaccine. Because polio viruses survive only in humans and are transmitted only by human contact, the World Health Organization (WHO) is trying to eradicate polio worldwide. This attempt has been relatively successful with a 99% decrease in polio infections worldwide. Great strides have been made in preventing Polio. It is caused by person-to-person transmission of polio viruses (enteroviruses, three main types). Not receiving the polio vaccine is the highest risk factor for getting infected with poliovirus. The viruses are only spread human to human by direct and indirect contact. Symptoms and signs of polio vary from no symptoms to limb deformities, paralysis, and death. Diagnosis of polio is based on the patient’s history, physical exam, and ongoing symptoms. The virus may be isolated from the patient’s tissues to confirm the diagnosis. There is no cure for polio; treatment is mainly supportive and is aimed at limiting or reducing the patient’s symptoms. For most patients, the prognosis is good because there are few or no symptoms; however, the prognosis declines rapidly as some patients develop more severe symptoms such as limb deformity, paralysis, difficulty breathing, and/or inability to swallow foods. It is possible to prevent polio by vaccination; it may be possible to eradicate polio. There are at least two types of polio vaccine (intramuscular injection or oral attenuated live vaccine), and both types are effective in preventing polio. A polio-like illness has recently been discovered in California in children that produces paralysis like that seen in some polio patients. Enteroviruses are a group of viruses that include the polioviruses (viruses that cause polio) along with other types of viruses called coxsackieviruses and echoviruses. Rhinoviruses (viruses that cause the common cold) are the most common viruses infecting humans.
The second most common viruses infecting humans are the non-polio enteroviruses (all the members of this virus group excluding the polio-causing viruses). Polio is caused by small RNA viruses. They are members of the enterovirus group of the Picornavirus family. There are three types (types 1, 2, and 3) of polio viruses; type I is responsible for about 85% of all paralytic infections. These types are antigenically distinct strains of viruses and infection or immunity to one type does not protect against the other two types, however, if immunity is established to one or all of the three strains, immunity is lifelong. The problem that these viruses cause is the destruction of spinal cord cells (specifically, the anterior horn cells). There are many risk factors for polio spread. Currently, the World Health Organization (WHO) have certified that the Americas, Western Pacific, and Europe are polio free. Other areas have a low incidence of polio, but people in war zones where vaccinations have been interrupted are at a risk getting polio (for example, Afghanistan and Syria). The greatest risk factor for polio is not being vaccinated. People with immunodeficiency (HIV, cancer patients, chemotherapy patients, for example), very young individuals, pregnant females, caregivers for polio patients, travelers to areas were polio is endemic, and lab personnel who work with live polioviruses are at increased risk for polio. Polio, like smallpox, only infects humans. It spreads by person-to-person contact; the virus lives in the throat and in the intestines and is spread through contact with the feces (fecal-oral spread) or by droplet spread in a sneeze or cough. It can also be spread by an infected person who has contaminated food or fluids by touching or tasting them. Unfortunately, a person can be infectious and transmit the virus even before they develop any symptoms. There are polio symptoms and signs. Fortunately, the vast majority of patients who are infected with polioviruses showed little or no symptoms and, in fact, don’t know that they actually had an infection with polioviruses. Those patients who do show symptoms can be placed in one of two groups; non-paralytic polio (minor) and paralytic polio (major). Non-paralytic polio infections develop flu-like symptoms that consist of fever, sore throat, headache, malaise, and muscle stiffness (neck, back). Some people may get a skin rash that resemble a measles rash type. These symptoms last about 10-20 days and they completely resolve thus termed nonparalytic polio. Although paralytic polio symptoms mimic the nonparalytic polio symptoms for about a week, increasing symptoms of severe muscle aches and spasms, loss of reflexes, and flaccid paralysis (limbs become floppy) begin to develop. In some individuals, the paralysis may occur very quickly (within a few hours after infection occurs). Sometimes the paralysis is only on one side of the body. The musculature involved with breathing may become inhibited or nonfunctional, and these patients need assistance with breathing. Post-polio syndrome describes symptoms that develop in patients about 30 to 40 years after an acute polio illness. The cause is unknown.
The post-polio syndrome symptoms include muscle pain, joint pain, and spinal changes such as scoliosis, spondylosis, and/or secondary nerve root and peripheral nerve compression. Slowly progressive muscle weakness (any muscles, including the eye muscles and sometimes termed bulbar polio), generalized fatigue, and cold intolerance may also occur. A physician may make a preliminary diagnosis of polio from the patient’s history and physical examination. For example, if the patient has not been vaccinated and has had contact with individuals who have polio and has symptoms such as muscle stiffness and difficulty with limb movements, breading or swallowing, then a preliminary diagnosis is made. A definitive diagnosis is done by cultivating poliovirus from the patient’s mucus, stool, and/or cerebrospinal fluid. In addition, there are serological tests that detect antibodies directed against poliovirus. Once the virus that causes polio has infected a person, there is no treatment that will cure polio. Early diagnosis and supportive treatments such as bed rest, pain control, good nutrition, and physical therapy to prevent deformities from occurring over time can help reduce the long-term symptoms due to muscle loss. Some patients, unfortunately, may require extensive support and care. For example, some require breathing assistance and special diets if they have difficulty swallowing while other patients may require splints and/or leg braces to avoid extremity pain, muscle spasms, and limb deformities. Some improvement in the symptoms may occur over time, but this improvement is not easily predictable and varies from patient to patient. For example, in the past, patients who needed breathing assistance would be treated with the iron lung. Over time, some would improve and no longer would require iron lung therapy. The prognosis for patients with polio depends on the extent of damage caused by the poliovirus. Many patients may have few if any symptoms and will have an excellent prognosis. However, the prognosis worsens when patients begin to show symptoms of paralysis, especially with decreased ability to breathe or swallow. Many patients who develop more severe polio symptoms progress to lifelong disabilities or death.
World Polio Day was established by Rotary International over a decade ago to commemorate the birth of Jonas Salk, who led the first team to develop a vaccine against poliomyelitis. Use of this inactivated poliovirus vaccine and subsequent widespread use of the oral poliovirus, developed by Albert Sabin, led to the establishment of the Global Polio Eradication Initiative (GPEI) in 1988. The 24th October is celebrated every year to eradicate polio which is a priority for governments, and to implement the strategy to eradicate polio, based on preventing infection by immunizing every child until transmission stops and the world becomes polio-free, as well as adopting polices and having the required funds to put the prescribed strategy in place. WHO is a partner in the Global Polio Eradication Initiative, the largest private-public partnership for health, which has reduced polio by 99%. Polio now survives only among the world’s poorest and most marginalized communities. In 2014, WHO announced that Southeast Asia was polio-free. However, some countries in Africa and the Middle East still have new infections caused by polio because of areas that cannot be reached by vaccine workers. Unfortunately, when there is war in these regions, polio makes a comeback because vaccine efforts are interrupted. The WHO still believes that polio eradication, like smallpox, may happen in the near future. It is possible to prevent polio by stimulating immune system with vaccination. Vaccinating individuals, especially young children, can establish lifelong immunity to the disease. The inactivated polio vaccine needs to be given at 2, 4, and between 6 and 18 months of age with a booster between ages 4-6. In addition, those people who care for polio patients need to be sure they have been appropriately vaccinated and still should use strict hygiene when caring for those patients. Eliminating polio will benefit the world in terms of health and economy. The eradication of polio can save at least $40–50 billion over the next 20 years.

(Dr. Syed Sabahat Asharaf is working at Regional Research Institute Of Unani Medicine, Srinagar and Dr Bilal A Bhat an associate professor at SKUAST-Kashmir. Their views are personal)

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