Viruses

A Look at Polio

Author Kristina Symes , 25-10-2020

Table of contents
An Egyptian stele thought to represent a polio victim. 18th Dynasty (1403–1365 BC).

An Egyptian stele thought to represent a polio victim. 18th Dynasty (1403–1365 BC).

 

Poliomyelitis dates back to ancient times, as captured in this 14th century BC Egyptian carving, detailing a typical symptom of atrophy in one or more of the limbs. 

The modern name, polio or poliovirus, is directly derived from Ancient Greek, poliós meaning ‘grey’ and myelós meaning ‘marrow’, the latter signifying the effect on the grey matter of the spinal cord.

But while the ancient Egyptians and Greeks knew about the disease, it wasn’t clinically described until the late 18th century (AD), by the English doctor Michael Underwood. The disease, now known as polio or poliovirus, was finally ‘formalized’ in the 19th century, thanks to the work of physicians Jakob Heine, who completed the first study on the disease, and Karl Oskar Medin, the first to detail the epidemic nature of Poliomyelitis. This led to the illness often being referred to as Heine-Medin disease rather than polio.

In March 2022, the World Health Organization (WHO) was notified of a few cases of polio circulating in Jerusalem, Israel. As of April 15th, 2022, one unvaccinated four-year-old child had symptoms of polio, but the rest of the six were asymptomatic. The polio cases detected in Israel are circulating vaccine-derived poliovirus type 3. 

 

Given that Israel is a highly-vaccinated country with regular surveillance for disease outbreaks, WHO considers this situation a moderate risk. Trace amounts of the poliovirus have been found in the sewage on the outskirts of Jerusalem, and more testing is underway to assess the actual health risk to residents. As a precaution, Israel began an immunization campaign with inactivated polio vaccines (IPV) and oral polio vaccines (OPV). This includes previously unvaccinated communities. 

 

As we see the news unfold, many of us have questions regarding the poliovirus, like: 

  • What does ‘circulating vaccine-derived poliovirus’ mean? 
  • What is the type 3 poliovirus? 
  • Are vaccinated children safe from poliovirus? 
  • Do we need a booster dose for polio even if we are vaccinated? 
  • Can you get polio from the vaccines? 
  • Can polio be eradicated? 

Podcast on Polio with Dr. Stephen Berger 

To make sense of the latest polio news for us, an infectious disease expert, Dr. Stephen Berger (MD), discusses polio cases, vaccines, and more on a podcast with Robert Herriman of Outbreak News. 

 

Polio in Israel with Dr. Stephen Berger

 

Dr. Berger is affiliated with the Tel Aviv Medical Center, Emeritus Associate Professor of Medicine at the University of Tel-Aviv School of Medicine, and co-founder of GIDEON informatics – the world’s most comprehensive database for infectious disease data.  

What is Polio?

Polio is an infectious disease caused by the poliovirus. It is also known as poliomyelitis. Most individuals infected with the poliovirus will not exhibit symptoms (and are not considered to have polio). According to the CDC, one in four may have flu-like symptoms for a few days. However, for the small percentage who experience symptoms, the poliovirus can affect their brain and spinal cord and lead to meningitis and limb paralysis. This paralysis can lead to severe disability and can be fatal. 

 

How Does Polio Spread? 

Polio is spread through water or food that has been contaminated with the feces of an infected person. The virus multiplies in the host; it is then excreted and can contaminate others. People who are asymptomatic can also transmit the virus to others. 

Do People Still Get Polio? 

The short answer is that yes, a small percentage of people still get polio every year. 

The Global Polio Eradication Initiative that started in 1988 was widely successful. While in the late 1980s, the poliovirus paralyzed over 350,000 children annually, that number was lowered to about 175 reported cases in 2019. However, due to the global COVID-19 pandemic and related lockdowns and political strife in certain countries, cases began to rise again.

Symptoms of the Infectious Disease: Poliovirus

Polio is highly infectious and is spread through the fecal-oral exchange, mainly affecting children under the age of 5 but adult cases are not uncommon. Symptoms of polio include fever, sore throat, headache, vomiting, and still neck.

Although the disease of polio is feared for its more extreme outcomes, such as paralysis, these develop in only 1-2% of all cases. Less than 10% of cases are fatal, with most infections of polio being asymptomatic.

Campaign to End Polio by Prevention and the Vaccine

It is unknown how many deaths Polio has caused through the ages, but a significant global campaign has been in place since the 1950s as a response to the epidemic in the United States. 294,094 cases were reported from 1944 to 1953; 108,159 from 1954 to 1963; and 514 from 1964 to 1973. The campaign, combined with the effective polio vaccine, has led to the country being declared polio-free in 1979.

The establishment of the Global Polio Eradication Initiative (GPEI) in 1988 had a huge impact on the fight to end poliovirus.  Over 2.5 billion children were vaccinated with the polio vaccine since then, with 20 million volunteers in 200 countries taking part in the campaign.

Fantastic progress in the prevention of polio has been made with wild cases dramatically reducing from an estimated global incidence of 350,000 in 1988 to only 33 reported cases in 2018 – but the work isn’t over yet. The infectious nature of the disease caused by poliovirus could easily lead to extensive outbreaks and see the numbers increase again, despite the effective vaccine, as has been recently observed with measles. 

Although Type 2 has not been detected since 1999, nine outbreaks of vaccine-strain virus infection were reported since the OPV2 withdrawal in 2016, posing a threat to its complete eradication. The last reported case of Type 3 was in Nigeria, back in November 2012.

 

Polio cases worldwide, 1996-today. GIDEON.

Wild polio cases worldwide, 1996 – today, GIDEON.

 

Now is the time for the final push to limit the disease to the history books (and databases). If you want to be a part of the solution, head over to End Polio Now and get involved! It could make the world of difference to those affected.

 

The GIDEON Difference

GIDEON is one of the most well-known and comprehensive global disease databases for infectious diseases like polio. Data is refreshed daily, and the GIDEON API allows medical professionals and researchers access to a continuous stream of data which can be helpful in disease prevention whether the disease is polio or something else entirely. Whether your research involves quantifying data, learning about specific microbes, or testing out differential diagnosis tools– GIDEON has you covered with a program that has met standards for accessibility excellence.

Author
Kristina Symes

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