Introduction
At the beginning of the twentieth century, one of the most feared and dangerous diseases in most countries was poliomyelitis. Every year, it used to paralyze thousands of children temporarily or even permanently, and a significant number of them died (“History of Polio,” n.d.). The purpose of this paper is to provide the background, signs and symptoms, causative agent, pathology, epidemiology, and host response of this disease. Moreover, information related to poliomyelitis’ diagnosis, treatment, and prognosis will be provided.
Background
The deformed and withered limbs of several Egyptian mummies make it evident that polio first occurred about six thousand years ago. In the twentieth century, and most notably in the 1940s and 1950s, the United States and the whole world faced the problem of poliomyelitis becoming epidemic. Unfortunately, a vaccine became available only in the 1950s, and until then, this disease was a real nightmare for the parents. In May 1988, the World Health Assembly decided to eliminate poliomyelitis. After that, “the estimated global incidence of polio has decreased by more than 99%” (Ranade, n.d.). Most of the developed countries’ elderly and immigrants, however, still face residual poliomyelitis.
Signs and Symptoms
Generally, there are two types of polio: nonparalytic and paralytic. The symptoms of the first type include sore throat, fever, fatigue, vomiting, headache, muscle tenderness or weakness, and back, neck, arms, or legs stiffness or pain (Mayo Clinic Staff, 2017). Signs of paralytic polio are the same and also floppy or loose limbs, severe aches or weakness of muscle, and loss of reflexes (Mayo Clinic Staff, 2017). The symptoms (if they appear) may last up to ten days.
Causative Agent
The causative agent of poliomyelitis is poliovirus; it is a serotype of the species Enterovirus C, which belongs to the family of Picornaviridae. Poliovirus is composed of a protein capsid and an RNA genome (“History of Polio (Poliomyelitis),” 2018). This causative agent of polio was first isolated in 1909 by Erwin Popper and Karl Landsteiner. It infects cells of humans by binding to CD155, an immunoglobulin-like receptor, on the surface of the cell.
Pathology
The virus is ingested into a person’s body with fecal contaminated water or food. Researchers note that “the initial multiplication occurs in the lymphatic tissue of the oropharynx (tonsils) and intestine (appendix), and dissemination to the regional lymphatics is followed by viremia” (“Polio,” n.d.). The spinal cord’s gray matter is inflamed, and in fatal cases, there is the destruction in the hypothalamus, cerebellar nuclei, reticular formation, and cerebral ganglia.
Epidemiology
This virus is spread by the respiratory and the fecal-oral route. In the pre-vaccine era, almost all children were infected with poliomyelitis, but immunization has dramatically reduced the incidence of polio. However, there are still several countries that are of particular concern to the European Regional Certification Commission for Poliomyelitis Eradication. There are several factors that contribute to continued polio transmission (“Disease factsheet about poliomyelitis,” 2018). They include low oral polio vaccine coverage, high incidence of diarrheal diseases, poor sanitation and health service infrastructure, and high population density.
Host Response
As soon as poliovirus reaches the nerve cells, the infection begins because the protruding receptors get attached to the virus particle. After getting inside the cell, the virus hijacks and starts controlling the assembly process of the cell (“Disease factsheet about poliomyelitis,” 2018). Then, in several hours, it makes thousands of copies of itself, kills the cell, and spreads the infection to other ones. The human immune system protects itself is by producing antibodies (“Disease factsheet about poliomyelitis,” 2018). They prevent polio from interacting with another cell by engaging the protein covering of the poliovirus.
Diagnosis
Generally, doctors can recognize poliomyelitis by specific signs and symptoms, such as difficulty breathing and swallowing, abnormal reflexes, and back and neck stiffness. In order to make sure and confirm the diagnosis, it is of vital importance to check several samples for poliovirus (Ranade, n.d.). They include a sample of cerebrospinal fluid, a colorless liquid that surrounds a person’s spinal cord and brain, stool, or throat secretions.
Treatment
The main problem is that there is still no cure for poliomyelitis, even though there is a vaccine. That is why the treatment’s focus is on preventing any possible complications, speeding recovery in various appropriate ways, and increasing the patient’s comfort (“Polio,” n.d.). Moreover, there are supportive treatments that include physical therapy or moderate exercise that help prevent loss and deformity of muscle function; particular portable ventilators that may assist breathing; and pain relievers (“Disease factsheet about poliomyelitis,” 2018). In addition, various surgical techniques may be used to treat those polio patients who have either failed or not had medical treatments.
Prognosis
For a significant number of patients with polio, the prognosis is rather good. Most of the infected people recover quite easily with no complications by following medical recommendations (“Disease factsheet about poliomyelitis,” 2018). Nevertheless, those patients who are diagnosed with paralytic polio have a prognosis that may range from poor to good (Mayo Clinic Staff, 2017). Unfortunately, some of them may have severe complications and become disabled for the rest of their lives.
References
Disease factsheet about poliomyelitis. (2018). Web.
History of Polio. (n.d.).
History of Polio (Poliomyelitis). (2018). Web.
Mayo Clinic Staff. (2017). Polio. Web.
Polio. (n.d.).Web.
Ranade, A. S. (n.d.). Poliomyelitis. Web.