Poliomyelitis

Poliomyelitis is an infectious disease caused by a virus; usually causes only mild symptoms but in rare cases can attack the brain and spinal cord and cause paralysis or death

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Oral Polio Vaccine

Poliomyelitis is a viral disease that can affect nerves and can lead to partial or full paralysis. It is caused by infection with the poliovirus which can be spread by direct person-to-person contact, by contact with infected mucus or phlegm from the nose or mouth, or by contact with infected feces. There are three basic patterns of polio infection: subclinical infections, nonparalytic, and paralytic.

Symptoms

Symptoms vary based on the pattern of infection and can range from asymptomatic with subclinical poliomyelitis to partial or full paralysis. Treatment is aimed at controlling symptoms while the infection runs its course. Since the development of the polio vaccine, the incidence of the disease has been greatly reduced. The prognosis depends on the form of the disease (subclinical, nonparalytic, or paralytic) and the site affected.

Post-Polio Syndrome

Post-polio syndrome (PPS) is a condition that can affect polio survivors decades after they recover from their initial poliovirus infection. Most people who get infected with poliovirus (about 72 out of 100) will not have any visible symptoms.

About 1 out of 4 people with poliovirus infection will have flu-like symptoms that may include:

• Sore throat
• Fever
• Tiredness
• Nausea
• Headache
• Stomach pain

These symptoms usually last 2 to 5 days, then go away on their own.

Poliomyelitis

More serious symptoms

A smaller proportion of people with poliovirus infection will develop other, more serious symptoms that affect the brain and spinal cord: Paresthesia (feeling of pins and needles in the legs) Meningitis (infection of the covering of the spinal cord and/or brain) occurs in about 1 out of 25 people with poliovirus infection Paralysis (can’t move parts of the body) or weakness in the arms, legs, or both, occurs in about 1 out of 200 people with poliovirus infection. Paralysis is the most severe symptom associated with polio, because it can lead to permanent disability and death. Between 2 and 10 out of 100 people who have paralysis from poliovirus infection die, because the virus affects the muscles that help them breathe. Even children who seem to fully recover can develop new muscle pain, weakness, or paralysis as adults, 15 to 40 years later. This is called post-polio syndrome.

Note that “poliomyelitis” (or “polio” for short) is defined as the paralytic disease. So only people with the paralytic infection are considered to have the disease.

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J. von Heine, Poliomyelitis, 19th Century

Transmission

Poliovirus is very contagious and spreads through person-to-person contact. It lives in an infected person’s throat and intestines. Poliovirus only infects people. It enters the body through the mouth and spreads through: Contact with the feces (poop) of an infected person. Droplets from a sneeze or cough of an infected person (less common).

You can get infected with poliovirus if: You have feces on your hands, and you touch your mouth. You put in your mouth objects like toys that are contaminated with feces. An infected person may spread the virus to others immediately before and up to 2 weeks after symptoms appear. The virus can live in an infected person’s feces for many weeks. It can contaminate food and water in unsanitary conditions. People who don’t have symptoms can still pass the virus to others and make them sick.

Prevention & Treatment

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Warmsprings busts

There are two types of vaccine that can prevent polio:

Inactivated poliovirus vaccine (IPV) given as an injection in the leg or arm, depending on the patient’s age. Only IPV has been used in the United States since 2000.

Oral poliovirus vaccine (OPV) is still used throughout much of the world.

Polio vaccine protects children by preparing their bodies to fight the poliovirus. Almost all children (99 children out of 100) who get all the recommended doses of the inactivated polio vaccine will be protected from polio.

Diagnostic Methods

Poliovirus can be detected in specimens from the throat, feces (stool), and occasionally cerebrospinal fluid (CSF) by isolating the virus in cell culture or by detecting the virus by polymerase chain reaction (PCR).

CDC laboratories conduct testing for poliovirus, including:

• Culture
• Intratypic differentiation
• Genome sequencing
• Serology
• Virus Isolation and Detection

Virus isolation in culture is the most sensitive method to diagnose poliovirus infection. Poliovirus is most likely to be isolated from stool specimens. It may also be isolated from pharyngeal swabs. Isolation is less likely from blood or CSF.

To increase the probability of isolating poliovirus, collect at least two stool specimens 24 hours apart from patients with suspected poliomyelitis. These should be collected as early in the course of disease as possible (ideally within 14 days after onset).

Real-time reverse transcription PCR is used to differentiate possible wild strains from vaccine-like strains (“intratypic differentiation”), using virus isolated in culture as the starting material.

Partial genome sequencing is used to confirm the poliovirus genotype and determine its likely geographic origin.

Serologic Testing

Serology may be helpful in supporting the diagnosis of paralytic poliomyelitis, particularly if a patient is known or suspected to not be vaccinated. An acute serum specimen should be obtained as early in the course of disease as possible, and a convalescent specimen should be obtained at least 3 weeks later.

Cerebrospinal Fluid Analysis

Detection of poliovirus in CSF is uncommon. CSF usually contains an increased number of leukocytes [from 10 to 200 cells/mm3 (primarily lymphocytes)] and a mildly elevated protein (from 40 to 50 mg/dL). These findings are nonspecific and may result from a variety of infectious and noninfectious conditions.

Glossary of Polio

• Albert Sabin - Developed the oral polio vaccine (OPV), which has been instrumental in efforts to eradicate polio.
• Ali Maow Maalin - The last person in the world to be infected with naturally occurring smallpox; worked to eradicate polio in Somalia.
• British Polio Fellowship - A charity organization that provides support and information to those affected by polio and post-polio syndrome in the United Kingdom.
• CD155 - The poliovirus receptor, a critical cell surface protein that poliovirus binds to initiate infection.
• Ciro de Quadros - A public health expert known for his work in immunization and a key figure in polio eradication efforts in the Americas.
• Contact immunity - A form of immunity that occurs when a vaccinated individual transmits the vaccine virus to unvaccinated individuals, indirectly immunizing them.
• Courage Kenny Rehabilitation Institute - Provides rehabilitation services for people with conditions such as post-polio syndrome.
• Cutter Laboratories - A pharmaceutical company involved in an incident where improperly inactivated polio vaccine led to cases of polio.
• DPT vaccine - A combined vaccine against diphtheria, pertussis (whooping cough), and tetanus, not directly related to polio but part of immunization programs.
• DTaP-IPV vaccine - A combination vaccine that protects against diphtheria, tetanus, pertussis, and poliovirus.
• DTaP-IPV-HepB vaccine - A hexavalent vaccine protecting against diphtheria, tetanus, pertussis, polio, hepatitis B, and Haemophilus influenzae type b.
• DTaP-IPV/Hib vaccine - A combination vaccine against diphtheria, tetanus, pertussis, polio, and Haemophilus influenzae type b.
• David Bodian - An American scientist whose research contributed significantly to the understanding of polio's pathogenesis.
• Elizabeth Kenny - An Australian nurse whose innovative treatment for polio survivors improved their rehabilitation.
• Enterovirus C - A group of enteroviruses including the three poliovirus types known to cause polio.
• Frederick Chapman Robbins - Shared the Nobel Prize for discoveries concerning poliovirus, leading to the development of polio vaccines.
• Global Polio Eradication Initiative - A public-private partnership led by national governments with five core partners, dedicated to the eradication of polio.
• Gu Fangzhou - A Chinese virologist who played a key role in developing and promoting the use of oral polio vaccine in China.
• H. R. Cox - Developed a vaccine for Rocky Mountain spotted fever; his work laid the groundwork for future vaccine development, including polio.
• Harry M. Weaver - A neuroscientist whose leadership at the National Foundation for Infantile Paralysis (now March of Dimes) funded critical polio vaccine research.
• Hexavalent vaccine - Combines vaccines against six diseases, including polio, to simplify vaccination schedules.
• Hilary Koprowski - Developed the first successful oral polio vaccine, though it was later replaced by Sabin's vaccine.
• History of polio - Chronicles the impact of polio through centuries, from early descriptions to major outbreaks and the development of vaccines.
• Howard A. Howe - Contributed to early polio vaccine development, particularly in creating a vaccine strain.
• India National PolioPlus - A Rotary International initiative aimed at eradicating polio in India, which was declared polio-free in 2014.
• Isabel Morgan - An American virologist known for her pioneering work on developing a killed-virus polio vaccine.
• Ivar Wickman - Identified polio as a contagious disease and contributed to the understanding of its epidemiology.
• Jakob Heine - The first to clinically describe polio in 1840, leading to the disease initially being named Heine-Medin disease.
• Jean Macnamara - An Australian doctor who, with Macfarlane Burnet, used monkeys to research polio and advocate for the benefits of vaccination.
• John Beale (virologist) - A virologist who contributed to the understanding of the molecular biology of poliovirus.
• John Franklin Enders - "The Father of Modern Vaccines," his work on cultivating poliovirus in tissue culture earned him a Nobel Prize and paved the way for the polio vaccine.
• Jonas Salk - Developed the first successful inactivated polio vaccine (IPV), which was introduced in 1955.
• Joseph L. Melnick - His research in poliovirus and enteroviruses contributed to the development of polio vaccines.
• Julius Youngner - A scientist who played a significant role in the development of the Salk polio vaccine.
• March of Dimes - Originally founded to fight polio, this American nonprofit now focuses on the health of mothers and babies.
• March of Dimes Canada - An organization that provides a range of services to people with disabilities, originally established to combat polio in Canada.
• Marguerite Vogt - A renowned cell biologist and virologist who made significant contributions to polio research, particularly in the cultivation of poliovirus in tissue cultures.
• Martha Dodray - A health worker known for her efforts in polio vaccination campaigns in India, contributing to the country's polio eradication.
• Maurice Brodie - An early researcher who, alongside John Kolmer, attempted to develop a killed-virus polio vaccine, though with limited success.
• Ontario March of Dimes - Now March of Dimes Canada, it began as part of the effort to eradicate polio and now provides programs and services to people with disabilities.
• Oral polio vaccine AIDS hypothesis - A controversial and widely discredited theory suggesting that the oral polio vaccine (OPV) could have contributed to the spread of HIV/AIDS.
• Paralytic polio - The most severe form of poliomyelitis, leading to paralysis, respiratory difficulties, and, in some cases, death.
• Polio - An infectious disease caused by the poliovirus, which can lead to paralysis and other severe health issues.
• Polio Children - A charity dedicated to providing education and assistance to children affected by polio, particularly in developing countries.
• Polio Hall of Fame - A monument at the Roosevelt Warm Springs Institute for Rehabilitation in Georgia, USA, that honors scientists and physicians who made significant contributions to the fight against polio.
• Polio eradication - The global public health effort to eliminate all cases of poliomyelitis (polio) infection around the world.
• Polio in Pakistan - Pakistan, along with Afghanistan, remains one of the last countries where polio is still considered endemic, with ongoing efforts to eliminate the disease.
• Polio vaccine - Vaccines used to prevent poliovirus infection; include the inactivated polio vaccine (IPV) developed by Jonas Salk and the oral polio vaccine (OPV) developed by Albert Sabin.
• Polio-like syndrome - Also known as acute flaccid myelitis (AFM), a condition that affects the nervous system, causing muscle weakness and paralysis similar to polio.
• Poliovirus - The virus that causes polio, an infectious disease that can result in paralysis and other serious health issues.
• Post-Polio Health International - An organization that provides information and support to those who have had polio and are experiencing post-polio syndrome (PPS).
• Post-polio syndrome (PPS) - A condition that affects polio survivors years after recovery, characterized by weakening muscles, fatigue, and pain.
• Pulse Polio - An immunization campaign established in India to achieve eradication of polio by vaccinating all children under the age of five years against the poliovirus.
• Raul Andino - A scientist known for his work on the molecular biology of poliovirus, contributing to the understanding and potential treatments of polio.
• Recombinant live vaccine - A type of vaccine being researched for polio that uses genetically engineered viruses to stimulate immunity without causing disease.
• SV40 - A simian virus that was found in some polio vaccine batches produced between 1955 and 1961, which raised concerns about potential health effects.
• Thomas Huckle Weller - Shared the Nobel Prize with Frederick Robbins and John Enders for their work on culturing the poliovirus, facilitating the development of vaccines.
• Thomas Milton Rivers - A virologist whose contributions laid the groundwork for understanding viral diseases, including polio.
• World Polio Day - An observance held on October 24 each year to raise awareness about polio vaccination and eradication efforts worldwide.

Also see

• Polio Hall of Fame

Poliomyelitis Resources
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