Polio is a highly contagious disease that is spread from person to person through contact with infected secretions from the nose, mouth, or infected stools. The virus enters the host through the mouth and replicates in the intestine, mainly affecting children under five years of age, especially those who are not potty trained (WHO, 2013). Poliovirus is composed of an RNA genome of approximately 7,500 nucleotides and a protein capsid. It infects human cells by binding to the CD155 receptor (the poliovirus receptor (PVR)) on the cell surface. The virus attaches to the host cell and creates a pore in the plasma membrane through which RNA is injected or the virus is ingested by the cell by endocytosis. Statistics from the Center for Disease Control and Prevention (CDC) show that about 72% of people infected with polio will have no symptoms and about 24% of infected people will have minor symptoms, such as fever, fatigue, nausea, headaches and flu-like symptoms. , stiffness in the neck and back and pain in the limbs. Less than 1% of polio cases result in permanent paralysis of the limbs (usually the lower limbs) and die when the paralysis affects the respiratory muscles (CDC, 2014). In 1789, in England, Michael Underwood was the first to clinically describe the disease as a debility of the lower limbs in children. The first epidemics were reported in the 19th century in Europe and in 1843 in the United States, reaching its endemic peak in the United States in 1952, with more than 45,000 cases of paralysis. There is no medicine or treatment for polio. During the epidemic years of the 1950s, patients with severe respiratory problems were placed in an "iron lung", a cylindrical chamber that surrounded the patient's body from the neck down, which used an al... .. middle of paper... ...In the event of a public health and endemic problem, people will be able to access polio vaccines worldwide, and children will not be vulnerable to painful lifelong polio paralysis. (WHO, 2013). References Centers for Disease Control and Prevention. “Polio in a Nutshell.” January 16, 2014. The web. February 27, 2014. http://www.cdc.gov/vaccines/vpd-vac/polio/in-short-both.htmCDC. Updated recommendations from the Advisory Committee on Immunization Practices (ACIP) regarding routine poliovirus vaccination. MMWR 2009;58 (No. 30):829–30.http://www.cdc.gov/vaccines/pubs/pinkbook/downloads/polio.pdfMarch of Dimes Foundation. "Polio." Polio. Np, and Web. March 2, 2014. http://www.marchofdimes.com/mission/polio.aspxWorld Health Organization. “Poliomyelitis Fact Sheet N 114”. WHO. Np, April 2013. Web. February 27, 2014. http://www.who.int/mediacentre/factsheets/fs114/en/