Tag: AFP

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)
  • last case of wild poliovirus type 2 (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 in the United States, a patient with a long-standing combined immunodeficiency who was probably infected in the late 1990s (2009)
  • last case of type 3 poliovirus (2012)
  • 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)
  • type 2 poliovirus eradicated (2015)
  • 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 two countries, Afghanistan 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

Is AFM a Form of Transverse Myelitis?

Acute Flaccid Myelitis (AFM) is a form of acute flaccid paralysis.

“AFM can be difficult to diagnose because it shares many of the same symptoms as other neurologic diseases, like transverse myelitis and Guillain-Barre syndrome. With the help of testing and examinations, doctors can distinguish between AFM and other neurologic conditions.”

About Acute Flaccid Myelitis

AFM is not transverse myelitis, Guillain-Barre syndrome (GBS), or Acute Disseminated Encephalomyelitis (ADEM) though, although anti-vaccine folks are trying hard to make a connection.

Is AFM a Form of Transverse Myelitis?

AFM is similar to transverse myelitis, in that they both affect a person’s spinal cord, but a big difference is that TM results from “an immune-mediated inflammatory attack of a person’s spinal cord.”

“This report and others indicate that AFM represents a unique subset of acute flaccid paralysis distinct from GBS and transverse myelitis. GBS typically presents with an ascending paralysis and can be associated with facial paralysis and sensory symptoms. Children with transverse myelitis have weakness and prominent sensory loss, often manifest as a spinal sensory level. By contrast, the majority of children with AFM have focal, poliomyelitis-like spinal cord paralysis with minimal or no sensory symptoms.”

Recognition and Management of Acute Flaccid Myelitis in Children

And AFM has different symptoms from both TM and GBS.

So why try to connect AFM with TM, GBS, and ADEM? Because they think that vaccines cause TM, GBS, and ADEM.

They don’t. Just like vaccines don’t cause AFM.

There is no proof in package inserts that vaccines cause AFM.
There is no proof in package inserts that vaccines cause AFM.

But can’t you find some of these things listed in the package insert for some vaccines?

Yes, but when mentioned in a vaccine’s package insert, like for autism, SIDS, or meningitis, it is in the section where it is clear that it is “without regard to causality.”

AFM is not transverse myelitis and neither are caused by vaccines.

We will hopefully learn what is causing the latest cases of AFM soon.

More on AFM and Transverse Myelitis

Do Vaccines Cause Acute Flaccid Myelitis?

Breaking News – 158 cases of AFM in 36 states have been confirmed so far this year, with an additional 153 cases under investigation.

Since 2014, we have seen several outbreaks of acute flaccid paralysis (the sudden onset of weakness in one or more arms or legs) across the United States.

Why?

We don’t know, except we do know that these folks don’t have polio, even though folks continue to get confused because the kids are described as having a “polio-like” disease. Every case undergoes extensive testing, including testing for polio and other viral infections.

Do Vaccines Cause Acute Flaccid Myelitis?

Tragically, like some other conditions of unknown cause, some people have grasped onto the idea that AFP could be caused by vaccines.

“Of 14 patients with available information, 12 had previously received polio vaccine; one child and one adult were unvaccinated because of personal belief exemptions.”

Acute Flaccid Paralysis with Anterior Myelitis — California, June 2012–June 2014

It shouldn’t be surprising that there is absolutely no evidence that this is any type of vaccine injury.

Of nearly 350 cases of the acute flaccid myelitis (AFM), or the subtype of AFP that we have been seeing since 2014, we know that:

  • most cases occur in children
  • they have a magnetic resonance image (MRI) showing spinal cord lesion largely restricted to gray matter and spanning one or more vertebral segments
  • AFM can be caused by viruses, environmental toxins, and genetic disorders, although no common etiology has been found in recent cases
  • cases are occurring sporadically – after 120 cases in 34 states in 2014, there were only 24 cases in 17 states in 2015, but then 149 cases in 39 states in 2016 and 33 cases in 16 states in 2017. And there have been at least 62 cases in 22 states in 2018.
  • most cases occur in the late summer and early fall
  • most had symptoms of a preceding viral illness, including respiratory symptoms or diarrhea
  • some were unvaccinated
  • the ages of affected children has ranged from 5 months to 20 years
  • some patients have recovered, while others have persistent paralysis
  • there has been at least one death
  • some, but not all, were positive for enterovirus D68
  • in Colorado this year, 9 of 14 cases were linked to EV-A71 infections
  • although there was a national outbreak of EV-D68 in 2014 that coincided with the first AFM cases, we didn’t see this kind of outbreak in the following years

So what’s causing these kids, with a median age of about 7 years, to develop acute flaccid myelitis?

We don’t know, but there is certainly no reason to think that it could be a vaccine, as some anti-vaccine folks suggest.

For one thing, several of the kids were completely unvaccinated!

And then, if it was a vaccine, why the seasonal pattern?

Would a vaccine injury have such a seasonal pattern – even skipping a year?
Would a vaccine injury have such a seasonal pattern – even skipping a year?

And why don’t cases occur in all states and at the same rates each year?

Also, why the big range in ages? After all, what vaccines do a 5 month old and a 20 year old have in common?

And the CDC has been looking at all possible causes.

“Our medical team has been reviewing vaccine records when available during this year’s investigation and do not see a correlation.”

Kristen Nordlund, CDC spokeswoman

Acute flaccid myelitis is not caused by vaccines. Hopefully we will soon find out what really is causing it and can figure out how to prevent it.

Want to prevent a type of acute flaccid paralysis right now?

Get vaccinated!

While AFM is a type of non-polio AFP, we have long had a vaccine that can prevent polio, which also causes acute flaccid paralysis.

More on Vaccines and Acute Flaccid Paralysis

Updated December 10, 2018

Did Modern Ventilators Replace the Iron Lung for Folks with Polio?

Believe it or not, some folks don’t think that vaccines work and that some diseases, like smallpox and polio, never really went away.

Residual paralysis that lasts more than 60 days is the strongest predictor that a case is really polio, which is why, in addition to testing for polio virus, the 60 day standard is used.
Want the real truth? Residual paralysis that lasts more than 60 days is the strongest predictor that a case is really polio, which is why, in addition to testing for polio virus, the 60 day standard is used.

Of course, they have special little theories for how this all works.

Did Modern Ventilators Replace the Iron Lung for Folks with Polio?

In addition to thinking that we just change the names of diseases when we want them to go away, some folks think that we don’t see anyone in iron lungs anymore, not because polio has been eliminated, but because modern ventilators simply replaced the iron lung.

Is that true?

The iron lung, invented in 1927, helped people with polio breath.

In fact, in the 1940s and 1950s, there were whole hospital wards full of polio patients in iron lungs.

Unlike most of today’s ventilators, the iron lung is a negative pressure ventilator. In contrast, most modern ventilators, the ones that you see people hooked up to with a tube going down to their lungs, are positive pressure ventilators.

Iron Lung

What’s the difference?

A positive pressure ventilator pushes air into your lungs. They are useful when you have a lung disease or simply can’t breath on your own.

When people had polio, there usually wasn’t anything wrong with their lungs – it was their chest muscles and diaphragm that were the problem. So the negative pressure in the iron lung would compress and decompress their chest.

One benefit of the iron lung included that it was less invasive than ventilating someone through a tracheostomy, which became an option in the 1960s. While many new options became available for those needing long term ventilation since then, including noninvasive positive pressure ventilation, some still like to use their iron lungs.

Thanks to vaccines, most folks will only see an iron lung in a museum and read about polio in history books.
Thanks to vaccines, most folks will only see an iron lung in a museum and read about polio in history books. Photo by Oscar Tarragó, M.D., M.P.H.

And while it is true that they don’t make them anymore, iron lungs have not disappeared. There are some folks with polio that still use them.

But what if someone developed polio now, would they be put in an iron lung?

No, they wouldn’t. For one thing, they don’t make iron lungs anymore. Instead, they would likely use mouth intermittent positive pressure ventilation.

Still, we don’t see a lot of folks getting diagnosed with polio, needing to use mouth intermittent positive pressure ventilation, instead of iron lungs these days. And that’s because we don’t see a lot of folks getting diagnosed with polio.

Vaccines work. Polio is almost eradicated.

What to Know About Polio, Modern Ventilators and Iron Lungs

Although some people with polio are still using their iron lungs, the main reason we don’t see more people with polio needing to use iron lungs or modern ventilators is simply because polio is almost eradicated.

More on Ventilators and Iron Lungs

The Myth That Polio Only Went Away Because They Changed the Way It Was Diagnosed

Have you heard this one?

“Before the vaccine was developed, the diagnosis of polio required 24 or more hours of paralysis. After the vaccine release, the diagnosis changed to at least 60 days of paralysis. As you can imagine, cases of polio dropped significantly.”

So that’s why polio went away?

It wasn’t the vaccine?

The Myth That Polio Went Away Because They Changed the Diagnostic Criteria

In 1952, there were 21,000 cases of paralytic polio in the United States.

But were there really?

Didn’t they change the way they diagnosed polio a few years later, right after the first polio vaccines came out, making it less likely that folks would be diagnosed with polio?

The original diagnostic criteria for polio came from the World Health Organization and included:

“Signs and symptoms of nonparalytic poliomyelitis with the addition of partial or complete paralysis of one or more muscle groups, detected on two examinations at least 24 hours apart.”

It changed in 1955 to include residual paralysis 10 to 20 days after onset of illness and again 50 to 70 days after onset.

Why?

“In the past children’s paralysis was often not correctly diagnosed as polio. Stool samples need to be analyzed to be able to distinguish paralytic symptoms from Guillain-Barré Syndrome, transverse myelitis, or traumatic neuritis.”

Polio – Data Quality and Measurement

But you coulld’t just use stool samples, as many kids might have recently had non-paralytic polio, and could test positive for polio (false positive test), but have another reason to have paralysis.

“Isolation of poliovirus is helpful but not necessary to confirm a case of paralytic poliomyelitis, and isolation of poliovirus itself does not confirm diagnosis.”

Alexander et al. on Vaccine Policy Changes and Epidemiology of Poliomyelitis in the United States

Since polio causes residual paralysis, the new diagnostic criteria helped to make sure that kids were diagnosed correctly.

Did We Overestimate the Number of Kids with Polio?

Some folks think that since we changed the criteria, we overestimated the number of kids with polio in the years before the vaccine came out.

Most of this idea seems to come from a panel discussion in 1960 by critics of the original polio vaccine, The Present Status of Polio Vaccines, including two, Dr. Herald R. Cox and Dr. Herman Kleinman, who were working on a competing live-virus vaccine.

None in the group were arguing against vaccines, or even really, that the Salk polio vaccine didn’t work at all though. They just didn’t think that it was effective as some folks thought.

“I’ve talked long enough. The only other thing I can say is that the live poliovirus vaccine is coming. It takes time. The one thing I am sure of in this life is that the truth always wins out.”

Dr. Herald R. Cox on The Present Status of Polio Vaccines

Dr. Cox did talk a lot about the oral polio vaccine. He talked about successful trials in Minneapolis, Nicaragua, Finland, West Germany, France, Spain, Canada, Japan, and Costa Rica, etc.

When anti-vaccine folks cherry pick quotes from The Present Status of Polio Vaccines discussion panel, they seem to leave out all of the stuff about how well the oral polio vaccine works.

That’s how they work to scare parents and hope that their anti-vaccine myths and misinformation can win out over the truth that vaccines work and that they are safe and necessary.

“Since nothing is available, there seems to be no alternative but to push the use of it. I don’t think we should do so in ignorance, nor too complacently, believing that as long as we have something partially effective there is no need to have something better.”

Dr. Bernard Greenberg on The Present Status of Polio Vaccines

And of course, they did, fairly soon, switch to something better – the Sabin live-virus oral polio vaccine.

Interestingly, using the idea that we changed the diagnostic criteria to make polio go away in an argument about vaccines is known as the Greenberg Gambit.

It tells you something about anti-vaccine arguments, that these folks are misinterpreting something someone said about vaccines almost 60 years ago.

In pushing the idea that polio hasn’t been eliminated, but rather just redefined, they also miss that:

But isn’t polio still around and just renamed as transverse myelitis, Guillain-Barré syndrome (GBS), and aseptic meningitis?

Let’s do the math.

Using the adjusted numbers in the The Present Status of Polio Vaccines discussion, there were at about 6,000 cases of paralytic polio in the United States in 1959.

While 3,000 to 6,000 people in the United States develop Guillain-Barré syndrome each year, the risk increases with age, and it is rare in young kids. Remember, paralytic polio mostly affected younger children, typically those under age 5 years.

“Transverse myelitis can affect people of any age, gender, or race. It does not appear to be genetic or run in families. A peak in incidence rates (the number of new cases per year) appears to occur between 10 and 19 years and 30 and 39 years.”

Transverse Myelitis Fact Sheet

Similarly, transverse myelitis is uncommon in younger children, and there are even fewer cases, about 1,400 a year.

What about aseptic meningitis? That doesn’t usually cause paralysis.

So do the math.

You aren’t going to find that many kids (remember, the incidence was 5-7 per 1,000) under age 5 years who really have “polio,” but instead, because of a worldwide conspiracy about vaccines, are getting diagnosed with transverse myelitis, Guillain-Barré syndrome (GBS), or aseptic meningitis instead.

Anyway, kids with acute flaccid paralysis are thoroughly tested to make sure they don’t have polio. And both transverse myelitis and Guillain-Barré syndrome have different signs and symptoms from paralytic polio. Unlike polio, which as asymmetric muscle atrophy, the atrophy in transverse myelitis and Guillain-Barré syndrome is symmetrical. Also, unlike those other conditions that cause AFP, with polio, nerve conduction velocity tests and electromyography testing will be abnormal. Plus, polio typically starts with a fever. The other conditions don’t.  So while these conditions might all be included in a differential diagnosis for someone with AFP, they are not usually that hard to distinguish.

“Each case of AFP should be followed by a diagnosis to find its cause. Within 14 days of the onset of AFP two stool samples should be collected 24 to 48 hours apart and need to be sent to a GPEI accredited laboratory to be tested for the poliovirus.”

Polio – Data Quality and Measurement

But why be so strict on following up on every case of AFP?

It’s very simple.

If you miss a case of polio, then it could lead to many more cases of polio. And that would tmake it very hard to eradicate polio in an area.

If anything, until the establishment of the Global Polio Eradication Initiative (GPEI) in 1988, it is thought that cases of polio and paralytic polio were greatly underestimated in many parts of the world!

And now polio is almost eradicated.

“DR. SABIN: Let us agree, at least, that things are not being brushed aside. Let us say that we might disagree on the extent to which certain things have received study. But I hope that Dr. Bodian realizes that nobody is brushing things aside. I would not have taken the trouble of spending several months studying viremia with different strains in chimpanzees and human volunteers, and viremia produced by certain low temperature mutants to correlate it with their invasive capacity, if I were merely brushing it aside.”

Live Polio Vaccines – Papers Presented and Discussions Held at the First International Conference on Live Poliovirus Vaccines

There is no conspiracy.

Think about it.

If they redefined how paralytic polio was diagnosed in 1955 as part of a conspiracy to make it look like the polio vaccines were working, then why did the number of cases continue to drop into the 1960s?

Shouldn’t they have just dropped in 1955 and then stayed at the same lower level?

After the switch to the Sabin vaccine, polio was on its way to being eliminated in the United States.
After the switch to the Sabin vaccine, polio was on its way to being eliminated in the United States, although there was an uptick in 1959, before we made the switch.

And why don’t any of the folks with other conditions that cause paralysis, like transverse myelitis and Guillain-Barré syndrome (GBS) ever have polio virus in their system when they are tested?

Also, if the renaming theory explains why the polio vaccine didn’t work, then why do anti-vaccine folks also need to push misinformation about DDT and polio?

What to Know About Polio Myths and Conspiracies

The near eradication of polio from the world is one of the big success stories of the modern era, just as those who push the idea that has all been faked is a snapshot of society at one of our low points.

More on Polio Myths and Conspiracies

Is Polio Returning to Venezuela?

Breaking News – further tests have found that the person with suspected polio did not have either wild polio or vaccine-derived poliovirus (VDPV). Could it still be polio? (see below).

Polio is on the verge of being eradicated.

In 2017, there have only been 118 cases of polio in the whole world, including 22 cases of wild poliovirus in Afghanistan and Pakistan and 96 cases of vaccine-derived poliovirus (VDPV) in the Democratic Republic of Congo and Syria.

So far this year, there have only been 15 cases of polio in the whole world, including 10 cases of wild poliovirus in Afghanistan and Pakistan and five cases of vaccine-derived poliovirus (VDPV) in the Democratic Republic of Congo and Nigeria.

Is Polio Returning to Venezuela?

Most of us are aware that vaccine-preventable diseases are just a plane ride away.

We see it, or at least read about it, all of the time, as we continue to see outbreaks of measles affecting our communities.

But polio?

Could polio return?

Venezuela has been polio free for nearly 30 years. The last case of a wild poliovirus infection was in March 1989. And yet ,there are now thought to be at least four cases of poliovirus, type 3 in the Delta Amacuro state of north east Venezuela, where they are also seeing cases of diphtheria and measles.

Report of polio in Venezuela

Among the polio cases is a 2-year-old boy who was unvaccinated, an unvaccinated child who lived next to him, and a partially vaccinated child 8-year-old who lived next door.

“It has been reported unofficially that it is polio vaccine virus.”

Venezuelan Society of Public Health Report

But what is the source of the polio vaccine virus?

We supposedly stopped using oral polio vaccines that can shed in January 2016, right?

Actually, we began the switch from trivalent OPV (tOPV) to bivalent OPV (bOPV) in 2016, removing the the type 2 polio virus that is most likely to cause VAPP. Making sure kids get a dose of IPV first also lowers the risk of VAPP. At least it does when kids get vaccinated according to plan.

“Other children from the same community were vaccinated in April 2018 with oral bivalent polio vaccine.”

PAHO on Epidemiological Update Detection of Sabin type 3 vaccine poliovirus in a case of Acute Flaccid Paralysis 

When did the first case appear? Although we are just hearing about it now, his symptoms began in April, right around the time another child received a bivalent oral polio vaccine.

“No additional AFP cases have been identified to date through active search for AFP cases carried out in the community.”

PAHO on Epidemiological Update Detection of Sabin type 3 vaccine poliovirus in a case of Acute Flaccid Paralysis 

Fortunately, in the past month, no further cases have been identified.

Children in Venezuela are supposed to get at least one dose of IPV (inactivated polio vaccine), followed by four doses of bOPV (bivalent oral polio vaccine).
Children in Venezuela are supposed to get at least one dose of IPV (inactivated polio vaccine), followed by four doses of bOPV (bivalent oral polio vaccine).

So what does this all mean?

For one thing, wild polio isn’t returning to Venezuela. And it doesn’t look like we will see a large outbreak of cVDPV, as there are no further cases of AFP in the area.

But it does illustrate that we can easily see a return of vaccine-preventable disease if we don’t keep vaccinating until they are eradicated. Remember, low vaccination coverage is associated with outbreaks of cVDPV. If everyone is vaccinated and protected, then they won’t get polio, whether it is wild type or shed from someone who was vaccinated.

Latest Updates on AFP in Venezuela

While a Sabin type 3 polio virus had been initially isolated from the stool samples of the unvaccinated 34-month-old boy with polio symptoms, further tests have now been completed.

“Tests carried out by the specialized global laboratory for genetic sequencing have ruled out the presence of both wild poliovirus and vaccine-derived poliovirus (VDPV). The latter- VDPV- is a Sabin virus with genetic mutations that give it the ability to produce the disease. There is no risk of spread to the community or outbreaks of polio from this case.”

PAHO

So what does he have?

The possibilities are non-polio AFP, as many viruses and other diseases can cause polio-like symptoms.

So why did he have the Sabin type 3 polio virus in his stool?

It is well known that the oral polio vaccines shed. Even though he was  unvaccinated, he was likely exposed to others in the community who were recently vaccinated, as it is possible to shed the vaccine virus in your stool. The attenuated (weakened) vaccine virus is unlikely to cause symptoms though, unless it develops the mutations found in VDPV strains, which this one didn’t.

“The child is being further evaluated clinically to determine alternative causes of paralysis. The final classification of the case of acute flaccid paralysis [to define whether or not it is associated with the vaccine] will be based on clinical and virological criteria assessed at 60 days after the onset of paralysis.”

PAHO

So despite what folks are reporting, they didn’t say that this case couldn’t be associated with the polio vaccine. We just know that it is isn’t wild polio and the virus doesn’t have the mutations associated with cVDPV strains, which can not only cause polio symptoms, but can also spread from one person to another, causing outbreaks.

Remember, although the attenuated vaccine virus in the oral polio vaccine is unlikely to cause polio symptoms, it sometimes can, in about 1 in 2.7 million doses.

“VAPP at this time can’t be ruled out, of course, as it’s one of the possibilities.”

Communications Officer
Global Polio Eradication Initiative

Could this child have VAPP?

“A VAPP case was most often defined as a case of acute flaccid paralysis (AFP) with residual paralysis (compatible with paralytic poliomyelitis) lasting at least 60 days, and occurring in an OPV recipient between 4 and 40 days after the dose of OPV was administered, or in a person who has had known contact with a vaccine recipient between 7 and 60–75 days after the dose of OPV was administered.”

Platt et al on Vaccine-Associated Paralytic Poliomyelitis: A Review of the Epidemiology and Estimation of the Global Burden

I guess we will find out in a few weeks, as his symptoms started at the end of April.

Still, remember that VAPP is not contagious.

What to Know About Polio Returning to Venezuela

Several cases of a vaccine strain of polio virus have been found in Venezuela, which is linked to low vaccinated levels.

More on Polio Returning to Venezuela

Updated June 17, 2018

Myths About Polio and Acute Flaccid Paralysis

Polio is one of the most well known causes of acute flaccid paralysis.

Although most people with polio infections have no symptoms at all, or just have a very mild illness, with a sore throat and a low grade fever, a small percentage can develop:

  • a loss of superficial reflexes
  • severe muscle aches and spasms in their limbs or back
  • an asymmetrical flaccid paralysis with diminished deep tendon reflexes

This acute flaccid paralysis only affects the child’s strength in the affected muscle groups – there is no loss of sensation. The severity of the symptoms and the disease depends on which muscles are affected the most. If it is just your legs, then you will have trouble walking. On the other hand, if it affects your chest, then you might not be able to breath, unless you are put on a ventilator (iron lung).

Acute Flaccid Paralysis

Thinking about it in the context of polio, it becomes easy to understand acute flaccid paralysis or AFP.

It is the sudden onset (acute) of a flaccid (floppy or poor muscle tone) paralysis (weakness or inability to move) of one or more muscles.

But what many people don’t understand, is that in addition to polio, there are many more non-polio causes of AFP.

Non-Polio AFP

Many of us got a crash course in non-polio acute flaccid paralysis (NP-AFP) a few years ago when we started hearing reports of kids developing polio-like paralysis in 2014. Now thought to be caused by enterovirus D68 infections (EV-D68), the paralysis followed respiratory tract infections in many of the affected children. All together, at least 120 children in 34 states developed acute flaccid paralysis that year.

Interestingly, EV-D68 is one of more than 100 non-polio enteroviruses. The virus that causes hand, foot, and mouth disease, coxsackievirus A16, is another. Others cause pinkeye, meningitis, or encephalitis.

Keep in mind that many other viruses and conditions can cause non-polio AFP too, including:

  • Guillian-Barré syndrome
  • toxins (botulism)
  • tumors
  • transverse myelitis
  • traumatic neuritis
  • other infections, including novel enterovirus C105, a non-polio enterovirus, and even tick-borne (Lyme disease) and mosquito-borne (Japanese encephalitis) infections

How do you determine the cause and how do you know it isn’t polio?

These kids with AFP typically have extensive testing to determine what is causing their AFP, including an MRI, antibody tests, and testing of their cerebrospinal fluid, etc. Although it isn’t always possible to identify a cause, you can at least rule out many potential suspects, like trauma, polio, and other infections.

Myths About Polio and Acute Flaccid Paralysis

Some folks don’t believe in non-polio AFP.

They believe that polio never really disappeared because vaccines don’t really work and that polio was simply renamed to, you guessed it, acute flaccid paralysis.

“Unbeknownst to most doctors, the polio-vaccine history involves a massive public health service makeover during an era when a live, deadly strain of poliovirus infected the Salk polio vaccines, and paralyzed hundreds of children and their contacts. These were the vaccines that were supposedly responsible for the decline in polio from 1955 to 1961! But there is a more sinister reason for the “decline” in polio during those years; in 1955, a very creative re-definition of poliovirus infections was invented, to “cover” the fact that many cases of ”polio” paralysis had no poliovirus in their systems at all. While this protected the reputation of the Salk vaccine, it muddied the waters of history in a big way.”

Suzanne Humphries, MD on Smoke, Mirrors, and the “Disappearance” Of Polio

What’s their evidence?

A rise in cases of non-polio AFP in India since 1997.

How do we know that there has been a rise in non-polio AFP cases in India since 1997?

It’s very simple and explains why there isn’t any data on before that 1997. 

As part of the strategy to eliminate polio in that country, starting in 1997, all cases of AFP started getting tested for polio. It was a way to track the effectiveness of the immunization program. If you were seeing too many cases of AFP caused by polio, then not enough people were getting vaccinated. On the other hand, if you weren’t seeing any cases of AFP in an area, then the testing and surveillance probably wasn’t getting none, since there will always be some cases of non-polio AFP.

Unfortunately, they found many cases to track. And the cases kept increasing, although more and more, they weren’t being caused by polio. At least not by live polio virus.

Were they caused by the polio vaccine?

In some cases, yes. It is well known that the live polio vaccine can rarely cause VAPP and cVDPV.

By 2015, after India was declared free of polio (the last case was in 2011), none of those cases of AFP were found to be caused by wild polio though. And India hasn’t had a case of cVDPV since 2010.

Why the increase in cases of non-polio AFP? It certainly isn’t because of Suzanne Humphries’ polio virus renaming conspiracy or any other anti-vaccine conspiracy involving the polio vaccine itself.

The 'data' that Susanne Humphries uses to try and make her case about AFP neglects to mention that in the pre-vaccine era, polio paralyzed 500 to 1,000 children in India each day! Those 180,000 to 365,000 cases of paralysis wouldn't fit on her chart though...
The ‘data’ that Susanne Humphries uses to try and make her case about AFP neglects to mention that in the pre-vaccine era, polio paralyzed 500 to 1,000 children in India each day! Those 180,000 to 365,000 cases of paralysis wouldn’t fit on her chart though…
If we simply renamed polio to non-polio AFP, why did the numbers drop for so long and then slowly start to increase? Shouldn’t it have been a rapid crossover?

More importantly,  why are the case of paralysis from non-polio AFP so much lower than the pre-vaccine era cases of AFP from polio?

And how come we rarely see large outbreaks of AFP like we did in the pre-vaccine era?

Sure, 120 kids in the EV-D68 non-polio AFP outbreak of 2014 is way more than any of us would like to see, but it is tremendously less than what we used to see in the pre-vaccine era from polio.

“Poliomyelitis is one of the important emergent viral diseases of the twentieth century… At its height, from 1950–1954, poliomyelitis resulted in the paralysis of some 22,000 U.S. citizens each year… Many thousands were left permanently disabled by the disease, while many others suffocated as a consequence of respiratory paralysis.”

Barry Trevelyan on the The Spatial Dynamics of Poliomyelitis in the US

While anti-vaccine conspiracy theories about AFP are as easy to dismiss as all of the rest they bring up,  what is behind the rise in AFP in some areas of the world?

Although one study that was published in Pediatrics, “Trends in Nonpolio Acute Flaccid Paralysis Incidence in India 2000 to 2013,” did find a correlation between the use of the OPV vaccine and the incidence of non-polio AFP, many experts think the rise is a result of better screening. Also, once polio gets under control, other more neglected diseases start getting more attention, like enteroviral infections. Not surprisingly, other parts of the world have had the same experience.

There is also the fact that in 2005, the Global Poliomyelitis Eradication Initiative began “to cast a wider net for poliovirus detection and to maximize sensitivity so that every poliomyelitis case is detected.” Why? If even a single case was missed, it could lead to continued outbreaks and would get in the way of polio elimination in the country.

“This large increase in NP-AFP cases, which represent AFP cases caused by agents other than poliovirus, probably reflects the excellent implementation of the expanded definition of AFP and highly sensitive surveillance and detection methods used by NPSP in India from 2005 onwards…”

C. Durga Rao on Nonpolio Acute Flaccid Paralysis in India

So did the polio vaccine recently cause 53,000 paralysis victims in India?

No. 

The polio vaccine has worked to get us on the brink of eradicating polio though.

What To Know About Acute Flaccid Paralysis

Acute flaccid paralysis can be caused by the polio virus, but non-polio acute flaccid paralysis becomes a more important cause once polio is eliminated in a region.

More About Acute Flaccid Paralysis