Milestones Towards the Eradication of Polio

There is a lot more interest in polio these days, but not because we are close to eradicating this deadly disease, but rather because of the emergence of cases of acute flaccid myelitis (AFM).

Although the cases have a different cause, the symptoms of AFM are the same that we used to see during the outbreaks of polio that used to hit each summer in the pre-vaccine era.

Polio

Surprisingly, in most people, the poliovirus doesn’t actually cause any symptoms. They simply have an asymptomatic infection.

In some others, the poliovirus causes flu-like symptoms, including a fever, sore throat, nausea, and a headache – symptoms that last about 3 to 5 days.

Much more rarely, the poliovirus causes meningitis or paralysis.

It is these cases of paralytic polio that most people are aware of and that panicked parents during summers in the 1940s and 50s.

In addition to respiratory problems (think iron lungs), polio causes muscle atrophy.
In addition to respiratory problems (think iron lungs), polio causes muscle atrophy. (CC BY-NC 4.0)

After having flu-like symptoms, those kids who would develop paralytic polio can develop pain and then flaccid paralysis.

“The most severe form, paralytic poliomyelitis, which is seen in less than 1% of patients, presents as excruciating episodes of pain in back and lower limbs. In children, the disease may present in biphasic form—a period of prodrome followed by a brief symptom-free period of 7 to 10 days and then appearance of asymmetrical paralysis of limbs. Flaccid paralysis is the hallmark with loss of deep tendon reflexes eventually.”

Mehndirattta et al on Poliomyelitis Historical Facts, Epidemiology, and Current Challenges in Eradication

Of course, polio wasn’t always called polio.

Other names have included infantile spinal paralysis, infantile paralysis, Heine-Medin disease, poliomyelitis anterior acuta, and acute anterior poliomyelitis.

The first use of the name “polio” came from Adolph Kussmaul, with his use of the term poliomyelitis anterior acuta, which was derived from the Greek polios “grey” and myelos “marrow” and itis “inflammation.” It was because he knew that it was caused by inflammation of the spinal cord gray matter, even if he didn’t know why.

Polio History

Polio didn’t just suddenly appear in the middle of the 20th century though, it was likely around for ages.

That this Ancient Egyptian priest's leg is smaller than the other and he uses a staff to walk suggests that he could have had polio.
That one of this Ancient Egyptian priest’s legs is smaller than the other and he uses a staff to walk could suggest that he had polio.

In addition to an Egyptian funeral stele (a stone slab used as a monument) portraying Roma the Doorkeeper from 1500 BCE that suggests he had paralytic polio, archeologists have found evidence of polio in skeletons as far back as the Neolithic period.

A medical book from 1789 likely describes people with polio.
A medical book from 1789 likely describes people with polio.

Still, we don’t really know how long polio has been around and we don’t know why we began to see more cases in the mid-20th Century, although there are theories, including, ironically, about hygiene. While we often credit improved sanitation and hygiene for helping to reduce mortality from many diseases, some think that this actually set us up for polio outbreaks, as we were no longer exposed as infants, when we still had some maternal immunity.

The one thing that we do know is that we are on the verge of eradicating polio, as there are very cases now, in just a few countries.

Polio Timeline and Milestones

In addition to the more ancient discoveries about polio, there is a lot to learn about vaccines and vaccine-preventable diseases if we look at the major milestones of this important disease.

Although in the end it is a success story, the road to figuring out what caused polio symptoms and how polio could be prevented was very long.

  • Michael Underwood describes what is thought to be paralytic polio in his book A Treatise on the Diseases of Children, with General Directions for the Management of Infants from Birth  in a section on “Debility of the Lower Extremities” (1789)
  • first reported outbreak of polio in Worksop, England (1835)
  • Jacob von Heine, head of an orthopedic hospital in Germany, publishes a monograph that describes 29 cases of paralytic polio, and actually attributes the condition to inflammation of the anterior horns of the spinal cord, although the cause was still not known (1840)
  • first use of the term poliomyelitis by Adolph Kussmaul (1874)
  • Nils August Bergenholtz reports on an outbreak of paralytic polio in Sweden (1881)
  • Karl-Oskar Medin, a pediatrician who reported on a polio epidemic in Sweden (1887), later presents his findings at the Tenth International Conference in Berlin (1890)
  • the first major outbreak in the United States is documented in Rutland County, Vermont and causes 132 cases of paralysis and 18 deaths (1894)
  • Ivar Wickman tracks cases of polio during an epidemic in Sweden in 1905 and was the first to suggest that polio was contagious and that you could get it from “those afflicted with the abortive type” (1907)
  • although they don’t actually identify the poliovirus, Dr. Karl Landsteiner and Dr. Erwin Popper  identify that a virus causes polio when they inject material from the spinal cord of a child who had recently died with polio into the peritoneum of two monkeys, both of which soon developed paralytic polio (1908)
  • Simon Flexner, first discovers polio antibodies (1911), but unlike other researchers at the time, pushes the theory that polio was spread by the olfactory route, instead of the fecal-oral route, which was why we saw the development of nose sprays, etc., to try and prevent polio, none of which worked of course
  • a large polio epidemic in the United States causes at least 27,000 cases and 6,000 deaths (1916)
  • Philip Drinker and Louis Agassiz Shaw invent the first iron lung, the Drinker respirator (1929)
  • Frank M. Burnet and Jean Macnamara proposed that there were antigenically different strains of poliovirus (1931)
  • John R. Paul and James D. Trask help figure out how polio was spread by identifying the polio virus in human waste and sewage samples (1932)
  • Maurice Brodie and John Kolmer have unsuccessful field trials of early polio vaccines, including allergic reactions and vaccine induced polio because of poor attenuation (1935)
  • Sister Elizabeth Kenny establishes a clinic in Australia to treat polio survivors (1932) and later publishes her treatment recommendations, Infantile Paralysis and Cerebral Diplegia (1937)
  • the National Foundation for Infantile Paralysis is founded by FDR to stop polio (1937)
  • the first March of Dimes fundraisers to stop polio (1938)
  • Carl Kling found traces of the poliovirus in the Stockholm sewage system (1942)
  • the Sister Kenny Institute is built in Minneapolis, as her treatment methods become widely accepted after years of controversy (1942)
  • the U.S. Army Neurotropic Virus Commission, including Albert Sabin, gets a grant from the NFIP to study polio in North Africa (1943)
  • Isabel Morgan actually developed the first inactivated polio vaccine, but only tested it on monkeys (1949)
  • John Enders, with T. H. Weller and F. C. Robbins, received the Nobel Prize in 1954 for their work on the cultivation of the poliomyelitis viruses (1949)
  • David Bodian creates the monkey model using field isolates of poliovirus and with Jonas Salk, identifies the three poliovirus serotyes (1950s)
  • Hilary Koprowki develops the first oral, live polio vaccine, (1950) although Sabin’s vaccine eventually gets licensed because it is thought to be less neurovirulent in monkeys and undergoes more testing
  • there are 58,000 cases of paralytic polio in the United States (1952)
  • Renato Dulbecco, with Marguerite Vogt, successfully grows and purifies polio virus (1952)
  • the Polio Pioneers vaccine field trial, led by Thomas Francis Jr.,  that proves that Jonas Salk’s polio vaccine is safe and effective begins (1954)
  • Jonas Salk gets approval for his polio vaccine (1955)
  • improperly inactivated polio vaccine from Cutter Laboratories (Cutter Incident) causes 40,000 cases of polio, 200 cases of paralysis, and kills ten people (1955)
  • Albert Sabin develops the first live, oral polio vaccine, which replaced Jonas Salk’s inactivated polio vaccine (1961)
  • that polio survivors can develop new, late complications or post-polio syndrome begins to get reported (1969)
  • last endemic case of polio in the United States (1979)
  • the National Foundation for Infantile Paralysis officially changes its name to the March of Dimes Birth Defects Foundation (1979)
  • the World Health Assembly adopts a resolution for the worldwide eradication of polio by 2000 and the the Global Polio Eradication Initiative is launched (1988)
  • last imported case of polio in the United States (1993)
  • the WHO Region of the Americas is declared polio free (1994)
  • “last” case of VAPP that was acquired in the United States (1999)
  • wild poliovirus type 2 eradicated (1999)
  • the WHO Western Pacific Region is declared polio free (2000)
  • the United States switches back to using the an inactivated polio vaccine because of concerns over VAPP (2000)
  • the WHO European Region is declared polio free (2002)
  • outbreak of vaccine derived polio among a group of unvaccinated Amish in Minnesota (2005)
  • last case of VAPP that was acquired outside the United States, an unvaccinated 22-year-old U.S. college student who became infected with polio vaccine virus while traveling in Costa Rica in a university-sponsored study-abroad program (2005)
  • last case of VAPP, a patient with a long-standing combined immunodeficiency who was probably infected in the late 1990s (2009)
  • seasonal reports of acute flaccid myelitis in the late summer and early fall, which might be caused by a non-polio enterovirus, are reminiscent of polio epidemics in the early part of the 20th century (2014)
  • Bob Sears says that it is okay to delay the polio vaccine on his alternative vaccine schedule because “we don’t have polio in the United States” (2015)
  • a global switch from trivalent OPV to bivalent OPV in routine immunization programs (2016)
  • polio remains endemic in just three countries, Afghanistan, Nigeria, and Pakistan (2018)

So it should be clear, that despite what some folks think, polio wasn’t conquered overnight. And Salk and Sabin obviously had a lot of help, although those are the names we most commonly hear connected with polio eradication.

“Until poliovirus transmission is interrupted in these countries, all countries remain at risk of importation of polio, especially vulnerable countries with weak public health and immunization services and travel or trade links to endemic countries.”

Global Polio Eradication Initiative on Endemic Countries

And to be clear, polio hasn’t yet been conquered.

There is still some work to do unless we want to see cases of polio and paralytic polio return.

That’s why it is important that you don’t skip your child’s vaccines, even for diseases that we don’t have in the United States anymore.

More on the History of Polio

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.