Polio has for a long time been one of the most debilitating diseases that indiscriminately affects people of all walks of life. Nonetheless, vaccination has been effective in almost eliminating this disease that has limited human progress over the years. Actually, polio is extinct in most countries. Nonetheless, due to the dangers that this disease possesses to most individuals, vaccination against polio is carried in most countries. In light of this, this paper will analyze the various forms of polio, and the polio viruses that lead to these uniquely different types of polio. Importantly, it will conduct an in-depth analysis of each type of polio disease, carefully pointing out the infected part in each type of polio and the symptoms. Further, this paper will check on the success of using vaccination in the treatment of polio and the various types of vaccines that exist. Finally, the paper will form a conclusion based on the analysis of the disease.
Keywords: Polio, symptoms, disease
Epic proportions of loss of life may one day lead to near extinction of the human race. One of the main executioners of human life has been disease, far more than the war. Notably, there are a number of diseases that have plagued us throughout time. That is, the black death in the 14th century, cholera, smallpox, influenza, yellow fever, tuberculosis, and modern day ebola in Africa. With regard to this plight, the world organizations and governments have co-joined to eradicate modern day diseases such as polio.
History of Polio
Since time in memorial polio has astronomically claimed lives over the millennia. To elaborate, ancient Egyptians have carvings depicting individuals with withered limbs. However, severe outbreaks began in the 20th century in Europe and the USA. As a result, in the 1940s and 1950s polio was recorded to have killed or paralyzed over 500,000 people each year all over the world (Koch & Koch, 2012). Today, polio has almost been eradicated from the face of the earth. Actually, polio is only endemic in two countries, Pakistan and Afghanistan (WHO, 2016).
Findings on Polio by CDC and WHO
Under the circumstances above, the CDC and WHO have directed extensive resources and time to the eradication of polio. Basically, polio is an infectious disease caused by the poliovirus and has no known cure. Polio is known by other names such as poliomyelitis or infantile paralysis. Poliovirus causes muscle weakening in about 0.5% of the cases. Consequently, this leads to an inability to move and may occur after a few hours or days (Koch & Koch, 2012).
Furthermore, apart from the weakening of the legs, weaknesses may also occur in the muscles of the neck, head, or diaphragm. Nonetheless, many individuals are able to fully recover from these attacks. In spite of this, statistically about 2% to 5% and 15% to 30% of children and adults respectively, having muscle weakness die. Additionally, 25% of cases show minor symptoms which may be misdiagnosed as not been polio (WHO, 2015). Some of the minor symptoms may be sore throats, fever, headaches, painful limbs, and stiff necks. In this case, the symptoms go away after few days or weeks and individuals go back to their lives without knowledge that they were suffering from polio. Consequently, there are no symptoms for up to 70% of infections. Moreover, the post-polio syndrome may occur later on in life after recovery (Koch & Koch, 2012). Generally, this may be characterized by a gradual development of muscle weakness. Notably, these symptoms are similar to the once that occurred at the time of the initial infections.
In general, the spread of the deadly polio virus is through the entrance of infected fecal matter into the body through the mouth. Additionally, infections can also occur through water or food contaminated by human feces. A less common way of infection is through infected saliva. Polio infected persons may unknowingly spread it to other people for about six weeks after infection. Typically, this is during the disease’s incubation period. Diagnosis of polio is usually done through laboratory findings by testing for the presence of polio antibodies in the patient’s blood (Hinman, Koplan, Orenstein, Brink, & Nkowane, 1988). Simply, this entails detection of antibodies that fight against it in the bloodstream or finding the virus present in the feces.
Signs and Symptoms of Polio
Polio infections may be broadly classified into two patterns namely, abortive poliomyelitis and paralytic or non-paralytic illness. To clarify, abortive poliomyelitis is a minor illness. Furthermore, it does not affect the central nervous system. In contrast, paralytic or non-paralytic is a major illness that affects the central nervous system.
However, poliovirus infection proves to be asymptomatic in individuals having normal immune systems. For this reason, minor symptoms such as respiratory infections, sore throat, gastrointestinal disturbances including nausea and vomiting, influenza- like illness, constipation, and abdominal pain may be realized. Rarely, say 1% of infections, affect the central nervous system. In this case, the individual suffers from non-paralytic aseptic meningitis. Non-paralytic aseptic meningitis is characterized by symptoms such as irritability, headaches, vomiting, lethargy, and fever amongst others (Hayden, Sato, Wright, & Henderson, 1989).
On a positive note, non-paralytic patients do not usually develop to be paralytic. Overly, it is estimated that only between one and five people out of a thousand advance to developing paralytic disease. Polio paralytic disease progresses steadily from developing weak muscles which then deteriorate further to poorly controlled muscles. Finally, the individual becomes paralyzed and is medically pronounced as having acute flaccid paralysis. Paralytic poliomyelitis is categorized as either spinal, bulbospinal, or bulbar depending on where the paralysis has occurred. In general, there are different classifications of the poliomyelitis disease caused by the three serotypes of poliovirus, type1, 2, and 3.
Basically, this type of polio affects about 1% of polio victims. More importantly, the poliovirus replicates itself and destroys motor neurons found in the motor cortex, as well as those found in the brain stem and spinal cord. In effect, this causes paralytic poliomyelitis disease. In addition, depending on the extent of inflammation and neuron damages, it may be classified as spinal, bulbospinal, or bulbar paralysis (Koch & Koch, 2012). Consequently, there is the production of lesions in not only the spinal ganglia, but also the vestibular nuclei, reticular formation, cerebellar vermis, and nuclei. Lesions occur due to the destruction of neuronal cells by the polio virus. As a result of this, the color and appearance of the gray matter are affected. To elaborate, the gray matter found in the spinal column appears swollen and reddish due to nerve cell destruction caused by the inflammation.
Furthermore, there are more damages to the hypothalamus and thalamus caused by the disease. In view of this, there are a large number of early symptoms for paralytic polio. For instance, paresthesia, constipation, difficulty in swallowing and urinating, muscle pains, high levels of fever, headaches, neck and back stiffness, weakness of muscles, and loss of deep reflexes are some of the common symptoms. Altogether, paralysis occurs shortly after the symptoms are realized. Simply put, paralysis takes its hold after the fever has broken and this may take a maximum of ten days. Moreover, there is a correlation between the development of paralytic polio and age.
Equally important, infections to the central nervous system cause nonparalytic meningitis in children, and rarely do they progress to paralysis. As a matter of fact, paralysis in children develops one in a thousand, and in adults it occurs one in every seventy-five infections. Not to mention, paralysis of one leg is most common among children below five years. However, it is more severe among the adults resulting in paralysis of the abdomen and chest, as well as paralysis of all four limbs (Hayden, Sato, Wright, & Henderson, 1989). By the same token, different types of serotypes of the poliovirus cause different rates of paralysis. Consequently, poliovirus type 1 causes the most severe paralysis and type 2 causes the least paralysis rate.
Spinal polio is the most common of all paralytic poliomyelitis. It is caused by infection of the motor neurons found in the anterior horn cells or the ventral gray matter section. Broadly, the infections of the motor neurons affect the patient’s motor skills. In fact, there is damage to the motor neuron ganglia which is caused by inflammation of the nerve cell. In light of this, destroyed nerve cells lead to muscles not being able to receive either brain or a spinal cord signal which leads to the development of muscle atrophy. With regard to this, the individual experiences muscle pain and fever. Further, after two to four days he/she has complete paralysis (Koch & Koch, 2012).
To put it differently, the extent of the paralysis highly depends on the spinal region that was affected. Essentially, the spinal cord may be affected in the lumbar, cervical, or thoracic regions. In addition, paralysis is commonly asymmetrical, therefore, it may affect either one leg and an arm or both legs and arms. Also, paralysis occurs more severely where the limb joins the rest of the body.
Bulbar Polio makes up about 2% of paralytic polio cases. It is caused by the destruction of nerves found in the bulbar brain stem region. Basically, the bulbar region connects the cerebral cortex to the brain stem and by destroying the brain nerves; the virus weakens the muscles around the cranial nerves. In effect, bulbar polio affects the glossopharyngeal, the vagus, and the accessory nerves. Consequently, the individuals experience difficulties in swallowing, breathing, and speaking (Koch & Koch, 2012). Moreover, difficulty in swallowing leads to a buildup of mucus secretions in the air passages which leads to suffocation and death of the patient. Another key point is that the disease causes other symptoms such as difficulty in chewing, experiences of double vision, pulmonary edema, facial weaknesses, and abnormal respiratory rates.
Simply, this is when paralytic polio individuals experience both spinal and bulbar symptoms. Bulbospinal condition is also called respiratory polio. Notably, the uppermost section of the cervical vertebrae is affected by the virus which leads to paralysis in the diaphragm. Worse still, the phrenic nerve needed to inflate the lungs is affected. Additionally, nerves that help one to swallow are also severely affected (Koch & Koch, 2012). Consequently, the individual is unable to breathe without a ventilator. Moreover, the patient’s condition is aggravated by paralysis of the arms or in some cases it may also affect the functioning of the heart and the alimentary canal.
Certainly, since there is no known cure for polio, vaccination is the only sure way to prevent humans from acquiring this disease. In light of this, there are two types of vaccines that prevent polio, the weakened but live polio vaccine and the inactivated poliovirus vaccine. Vaccination through either way enables an individual to fight off possible polio infections (Hinman, Koplan, Orenstein, Brink, & Nkowane, 1988). Noteworthy, vaccination highly reduces transmission rates from one person to another.
Virologist Hilary Koprowski developed the first polio vaccine in February 1950. Essentially, it entailed the use of a weakened but live polio virus being introduced into the human body. In 1955, Jonas Salk introduced the second line of polio vaccine that was made using inactivated poliovirus vaccine (IPV) which was transmitted into the body through an injection. Consequently, 90% of individuals who are given two doses of the polio vaccines develop antibodies to all forms of poliovirus infections (CDC, 2016). Furthermore, after a third dose, it is reported that 99% become immune (Koch & Koch, 2012).
Subsequently, another scientist called Albert Sabin developed an oral polio vaccine best known as OPV. One dose of the vaccine guarantees immunity to all forms of poliovirus diseases in 50% of recipients. However, three doses result in 95% protection from the poliovirus menace. In 1958, OPV was chosen by the US National Institute of Health, along with those of other scientists like Koprowski to be used in the fight against polio (CDC, 2016). On a positive note, OPV has proven to be inexpensive, effective, and easy to administer. In light of this, it is widely accepted by many countries all over the world as the chosen vaccine in the fight against poliomyelitis (Hayden, Sato, Wright, & Henderson, 1989).
In summary, polio has been known for over one millennium as a deadly killer, and a major cause of limitation to human economic and social progress through paralysis. Over the ages, it has claimed millions of lives and crippled many individuals robbing them a chance to fulfill their dreams. However, with the breakthrough of modern science, we can eradicate polio from our communities. Actually, polio has almost been eliminated in most parts of the world and has effectively shown the positive impacts of vaccination in public health.
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