I MAY have, probably have, known someone who had polio, my late grandmother (who did, ftr, know people who died in the great flu pandemic when she was a teenager) and all of her 5 kids included, but I don’t personally know of anyone who experienced complications from polio.
I am 44.
I did a great deal of research on this years ago, as part of a larger research project on incidence, complications and mortality rates from all of the (then) VPDs (vaccine preventable diseases), but unfortunately, all my stuff is on floppy disc and, at the moment, inaccessible. Too bad, 'cause I really had all the numbers and cites and everything all trussed up SO nicely. Still DO, just can’t get to it on my new and improved computer :smack:
To sum up, off the top of my head:
Polio is actually a very interesting exception to the typical VPD in that complications and mortality associated with it coincided with IMPROVEMENTS in public sanitation, living conditions, hygiene and access to medical care. For virtually all other infectious diseases/VPDs, the opposite is true. (for measles, for instance, mortality had declined by 85% to 90% in the US and UK well before the vaccine was introduced, largely due to improvements in sanitation, nutrition and access to medical care for complications).
There were no reported epidemics of polio prior to the 18th century or so, and even then, they tended to occur in more developed areas.
Understanding why this was the case is key and complex.
Polio used to be an almost universal childhood infection. Meaning virtually every infant or young child was exposed, infected and gained lifelong immunity via contact with fecally contaminated water.
With rare exceptions, they recovered without any lasting harm. For most, there were no symptoms at all. For some, it took the form of a mild, flu-like illness followed by full recovery. For a very few (less than 1-2% at most, from my research), there was some form of residual effect (paralysis, weakness). In a very, very few cases, death resulted.
These complication/mortality rates still hold true, ftr…believe it or not, polio actually has a LOWER overall incidence of complications and mortality than the flu or even the common cold. Not to dismiss such complications out of hand, but based on the stats, they are rarer than those from other illnesses we take for granted.
One key factor is age at first exposure; the older one is at first exposure to the polio virus, the more likely one is to experience a more severe course (which also sets it apart form several other infectious, VPD diseases, in which middle childhood is the ideal time to contract).
In the past, it was most commonly contracted in infancy or early childhood, as most water supplies were contaminated to some degree with fecal matter and the very act of bathing or nursing or drinking water served to infect. The polio virus was pretty much ubiquitous.
But once the water supplies were cleaned up and exposure became far less likely, an increasing number of infants and toddlers were never exposed/infected/“immunized” to the virus, leaving them vulnerable to infection at older ages, when polio is more likely to assume a symptomatic or even severe form.
In the relatively sterile environment of the US circa the early decades of the 1900’s, a large percentage of the population had never had the chance to be exposed at a young age and gain immunity. They were sitting ducks.
There is also much evidence that polio, like many infectious diseases, is cyclical in nature, waxing and waning in any given population for as yet not fully understood reasons.
And as a primarily orally transmitted infection, the common practice of removing the tonsils (now recognized as a component of the immune system and esp. important in protecting against orally transmitted infections, but at one time considered a rudimentary, useless organ and yanked out en masse) may have influenced rates of infection/complications in the US as well.
As could have the emerging practice of formula feeding. Breastmilk is known to kill the polio virus in the gut and provide antibodies when from an immune mom; the UN noted this in its deliberations over how best to approach the polio issue…BFing mothers would kill the live virus vaccine in the gut of their infants, BUT BFing served so many other important health benefits, they could hardly discourage it.
Another interesting note is that the symptoms of polio (when clinically apparent) mirror those of pesticide poisoning (pesticides were first widely used in the US during the period of the US polio epidemics).
They are also clinically identical to viral meningitis. I examined a study which concluded that it was highly likely that many “polio” cases reported at the time were actually due to meningitis or some other cause. A look at the rates of each condition in several US counties shows a steep increase in “polio” and an almost exact decrease in “meningitis” in the years following widespread awareness of the polio epidemic. Some medical historians have interpreted this as an over-reporting of symptomatic polio due to diagnostic bias.
Regardless, the polio epidemic seen in the US at that time can be seen as a perfect storm of circumstances all coming together to result in an apparent epidemic in which a far higher percentage of those infected manifested clinical symptoms and experienced complications.
There have been problems with the vaccine, as praised as it is (and I want to go on record as stating that I believe Salk had the best of intentions and was a great man, donating his work to the public because, as he put it, “can you patent the sun?”).
The original version was found, in 1960, to have been contaminated with SV40, a previously unknown simian retro- virus now known to cause cancer in rodents and monkeys and which has been isolated from fatal tumors removed from humans. The source of the contamination was the monkey kidneys used to culture the vaccine. It took a few years for the contaminated vaccine to be used up/removed from circulation, so anyone who got a dose prior to 1962 or so is possibly infected with this retro-virus which is transmitted sexually and via blood transfusion, birth and organ transplants.
The switch to the injected, “killed” version of the vaccine was made in response to a number of cases of contacts with the live, oral vaccine recipient becoming infected and suffering lasting complications (one case I recall was a father, vaccinated against it as a child, who contracted it by changing the diapers of his recently vaccinated infant. It took years for him to get a definitive diagnosis because no Dr. could accept that he had polio. He did, and it was the vaccine strain).
The change-over was delayed many years, despite the fact that the ONLY reported cases of polio in the US and some other developed areas were due to the vaccine, because it was known that the live vaccine “sheds” for some time (7 yrs was the median estimate, longer in the immune depressed) and this was seen as a benefit (since in populations where there IS fecal contamination, it served to immunize infants and young children who might otherwise not be vaccinated).
How ironic…they had all but eradicated the wild polio virus and now felt compelled to re-introduce it into the environment to PREVENT serious illness. :smack:
For whatever it’s worth. Lots of anecdotal reports here, and I don’t discount them. Any injury or death is worthy of acknowledgment and honor. But this is, imo, a classic case of confirmation bias…we only know or notice those who experienced visible sequela and have no idea how many others also “had polio” and exhibited no ill effects. Ourselves included. Just offering up some of what I gleaned from my research into this fascinating virus and its interactions with its human hosts. Such interactions are very complex and
they interest me. There it is. 