Mark Blaxill and Dan Olmsted: Merrily confusing correlation with causation for polio (conclusion)

I concluded last week with the dismantling one of the more bizarre stories I’ve seen spun by the merry band of anti-vaccine propagandists over at Age of Autism. As you might recall, Mark “Not a Doctor, Not a Scientist” Blaxill had teamed with Dan “Where are the Autistic Amish?” Olmsted (or, as I call them, B&O) to produce what was at that time a five part “epic” of pseudoscientifically and enthusiastically confusing correlation with causation. I’m referring to what they called “The Age of Polio,” a title that made me wonder if B&O are terminally without imagination in that they seem to like to call everything the “Age of”…whatever. First we had “the age of autism”; now we have “the age of polio.” What’s next? No, wait. Don’t answer that. I don’t want to know.

In any case, the “Age of Polio” is a multipart “expose” of what B&O claim is the real story behind polio, and it’s a doozy. According to B&O, polio isn’t caused by the polio virus. Well, not exactly. Their claim is that polio epidemics came about not because of the virus but because somehow the virus interacted with pesticides, first lead arsenate compounds first introduced in the Boston area in 1893 and then, when the use of lead arsenate compounds was on the wane in the 1940s, DDT, which was introduced in the late 1940s. As I pointed out before, it’s truly amazing how two pesticides with such different chemical compounds and mechanisms of action could somehow both interact with the same virus to cause the same neurotoxicity in the spinal cord leading to paralysis, but plausibility was never anything that bothered anti-vaccine activists much. Certainly it didn’t bother B&O at all, because they then proceeded to cherry pick data to make it look as though there were a perfect correlation between these pesticides and polio epidemics. An even more egregious offense against epidemiology, math, and science, they tried to demonstrate a “breakpoint” around 1893 when they thought that the number of polio outbreaks made an abrupt increase, apparently based purely on visual cues, rather than doing any sort of unbiased statistical analysis to identify whether (1) there actually was a break point in the curve and (2) when it was. By “eyeballing it” alone, one could just as easily have chosen a point 10 or 20 years earlier.

Be that as it may, towards the end, B&O pointed out that polio outbreaks are still a problem in many parts of the world and left us with a teaser, in which they promised to explain how, given that lead arsenate compounds and DDT have phased out, there could still be polio outbreaks if their “theory” (and I do use the term incredibly loosely) were true. I facetiously speculated that they’d somehow figure out a way to bring mercury into the picture. Sadly, I was mistaken. Even more sadly, the real answer was more brain meltingly idiotic than anything I could possibly have thought of. You’ll see what I mean in am minute. In the meantime, I will add the two links for the newest parts of B&O’s epic of pseudoscience, so that you can see all seven parts in their stupid glory:

So let’s pick right back up with part 6. I’ll cut to the chase. The answer to the reason why there are still polio outbreaks despite the fact that lead arsenate pesticides were phased out decades ago is…arsenic. No, really. I kid you not. After noting that there are two areas where polio has resisted elimination, namely South Asia (Afghanistan, Pakistan, northern India), and Africa (basically, Nigeria), B&O go on to speculate wildly:

If one considers the toxin idea, however, another explanation jumps out, especially in South Asia. Erase national borders for a moment. While outbreaks are small and have waxed and waned over the past decade, the primary sites have been directly south of the Himalayan range in a smiley-face arc that runs west from Nepal and Bangladesh, through the Northern India districts of West Bengal, Bihar and Uttar Pradesh, into Pakistan and Afghanistan.

This also happens to be the area with the worst mass poisoning from arsenic in human history. This is not ancient history – it didn’t even begin until the 1980s. It is a story of the single-minded war against microbes gone badly wrong. What happened is beautifully outlined in an American Scientist article, “No one checked: Natural Arsenic in Wells.”[ii]

The mind boggles. In particular, there’s a huge inconsistency in B&O’s story. In fact, it’s a hole big enough to drive an arsenic-laden freighter through. Remember back in part 2 of their saga, when B&O tried to claim that it was the rise in the use of lead arsenate-based pesticides that led to an interaction between the lead arsenate compounds and the polio virus, making the virus more virulent and paralytic? Basically, that’s the whole reason they picked 1893-1894 as their break point after which the number of polio outbreaks supposedly skyrocketed. They even pointed out that Paris Green and London Purple, the two state-of-the-art arsenic compounds that were potent against most pests and used as pesticides at the time, didn’t work at all against the Gypsy moths that were threatening agriculture in late 19th century New England. In fact, according to B&O, the gypsy moth invasion was the impetus that lead to experimenting with lead arsenate compounds to make them deadlier to the moths.

So here’s the inconsistency. B&O point out that arsenic compounds were widely used as pesticides before 1893 but that it was only in 1893 that lead arsenate was developed and shown to be effective against the gypsy moth. It was only in 1893-94 that lead arsenate compounds began to be widely used as pesticides. It was also in 1893, according to B&O, that the first bigger polio outbreaks were noted in the Boston area, outbreaks that, according to B&O presaged the huge outbreaks to come in the early part of the 20th century. To them, this is evidence that it was lead arsenate compounds combining with the polio virus that lead to outbreaks of paralytic polio. it’s a massive confusion of correlation with causation, but apparently B&O are more than happy to let their story mutate when the facts become “inconvenient.” No more lead arsenate compounds? Well, then, it must have been the DDT! No more DDT? Then it must have been the arsenic contamination of groundwater! But wait! Didn’t they say earlier in the series that there were few outbreaks of polio back when arsenic-based pesticides were widely used, back…oh, you know…before 1893. So, basically, arsenic plus polio doesn’t cause paralytic polio outbreaks, but lead arsenate plus polio does; that is, except when it’s convenient to say that arsenic plus polio can cause outbreaks.

Of course, consistency never was one of B&O’s strong points. Purity of message is, and they never let inconsistencies, major or minor, get in the way of their purity of message. In fact, even while blaming arsenic for recent polio outbreaks they have to try to explain away inconvenient facts, such as why there are have been no recent polio outbreaks in Bangladesh, an area that apparently has had some of the worse arsenic contamination of its drinking water:

Why, given the arsenic disaster in Bangladesh, are there no recent polio cases there? It appears the virus has been wiped out. “Concerted efforts to eradicate polio in Bangladesh, resulted in the country being declared polio free in August 2000.”[xii]

B&O just undermined their entire implication that the polio vaccine isn’t as great as scientists believe. After all, B&O just admitted that vaccination campaigns eradicated polio in Bangladesh, and that’s why, despite the arsenic contamination problem, there hasn’t been any polio there. Not that this stops B&O from declaring:

Polio outbreaks, we believe, are persisting today for the same reason they arose. South Asia is simply a place where toxic interactions are triggering outbreaks that highlight the presence of the virus, like Luminol bringing out hidden blood splatters at a crime scene.

That would seem to spell trouble for programs guided by the belief that going after polio outbreaks will eradicate the virus – despite the vast resources currently being thrown at the effort.

Not surprisingly, a far more likely (and plausible) explanation besides a fantastical alleged interaction between arsenic and the polio virus is one that does not reflect well at all on the anti-vaccine movement. That explanation for the persistence of polio outbreaks in Afghanistan, northern India, Pakistan, and West Africa is the persistence of reservoirs of unvaccinated people. Indeed, I wrote about that very issue a very long time ago, back when this blog was still new, in a post entitled Polio returns, thanks to anti-vaccination zealots. For instance, in Pakistan in 2007 clerics declared polio vaccination an “American plot“:

The parents of 24,000 children in northern Pakistan refused to allow health workers to administer polio vaccinations last month, mostly due to rumours that the harmless vaccine was an American plot to sterilise innocent Muslim children.

The disinformation – spread by extremist clerics using mosque loudspeakers and illegal radio stations, and by word of mouth – has caused a sharp jump in polio cases in Pakistan and hit global efforts to eradicate the debilitating disease.

The result was:

Even though only 24,000 children missed the vaccine, the WHO officials said failure to vaccinate in small pockets of the country gave the virus a fresh toehold to spread.

There have been similar campaigns in Nigeria:

“Muslim leaders in hundreds of northern Nigerian communities such as Batakaye limited or halted door-to-door polio immunization last year. They told millions of faithful in this Muslim-dominated region that the American government had tainted the vaccine with either infertility drugs or HIV, the virus that causes AIDS — statements later proved false by independent laboratory tests.

“Some leaders admitted in interviews late last year that they never believed such a thing. But they remained silent, they said, in order to stop anything associated with the United States. The US-led wars in Iraq and Afghanistan, several said, had led them to believe that America wants to control the Islamic world, and the polio vaccination effort gave them an opportunity to resist a US-funded initiative.

It is probably not a coincidence that Nigeria is one of the four countries in which polio remains endemic. Nor is it likely to be a coincidence that northern India is also one of the places where polio remains endemic. Heck, all B&O would need to do to know this is check out the Wikipedia entry on polio eradication, where it is explained:

The epidemic occurred after the number of planned polio vaccination campaigns was reduced in India in 2002. Additionally, as many as 15% of homes were not visited during the vaccination activities which did take place that year.

it was also noted that there seemed to be a higher transmission rate in Bihar district and Uttar Pradesh, and a relatively low (~80% after three doses against type 1) seroconversion response seen from the vaccine.

In all areas where polio remains endemic, medical infrastructure, and problems resulting from it, sometimes with resistance to vaccination mixed in to help depress vaccine uptake, result in vaccination rates too low to achieve herd immunity, leaving a reservoir of unvaccinated people from which the virus can emerge when conditions were right. A not inconsiderable obstacle has also been difficulties in maintaining the potency of the oral polio vaccine, which must be stored at 2° to 8° C, something that’s not always easy in tropical climates far from large cities.

The last part of the “age of polio” series is where B&O concentrate their most potent stupid into a flaming blast of idiocy that will consume the reader like flame from the Human Torch. However, this flaming stupid does reveal an insight into the mind of an anti-vaccine activist. Basically, they hate and fear the success of vaccination programs, and few vaccination programs in history have been as successful as that against polio. Over the last five decades, polio has been beaten back from a world wide endemic disease to isolated pockets in a few backwater areas in Asia and Africa. There, the polio virus can only hold out because of a combination of factors, including religion-inspired anti-vaccine loons, that prevent the populations there from being vaccinated to levels that allow herd immunity to take hold. Yet, to B&O, pointing this out is “triumphalism” that is hateful to them:

Yet triumphalism is an ongoing legacy of The Age of Polio. Merely invoking the word today can shut down debate over public health, especially concerns over any aspect of vaccination policy.

Not exactly. A better way of looking at it is that anti-vaccinationists like to try to minimize and downplay the power of vaccination to eradicate infectious disease and don’t like it when examples are given that prove their dismissal of the power of vaccines to promote public health to be not based in science, evidence, or reason. That’s why B&O need so desperately to downplay the significance of the virus and add environmental toxins to the mix. Downplay the importance of the virus, and you downplay the importance of the vaccine. Exaggerate the importance of environmental toxins (or make up a correlation out of whole cloth), and you make the vaccine-autism hypothesis suddenly sound somewhat plausible. Add on top of that stories about the risks of the oral poliovirus, such as the Cutter incident, and it’s so much the better for vaccine denialists.

So B&O conclude:

The suffering of polio’s victims is honored by learning all of its lessons, including the danger of environmental toxins and the perils of ignoring their role in modern disease; the risk of focusing all of our energy on vaccinations as magic bullets, and the fundamental ethical obligation to search for the truth without fear or favor. Only then can we work out the real nature of illnesses that confront us here and now, ranging from autism to Parkinson’s to the persistence of poliomyelitis itself. Only then can we begin to prevent such disasters as The Age of Polio.

Except that B&O profoundly dishonor the suffering of polio’s victims by trying to use pseudoscience and the willfully ignorant confusion of correlation with causation to obfuscate and confuse, to blur the true cause of polio and simultaneously to make their vaccine pseudoscience sound superficially plausible. In their “Age of Polio” series, B&O just took a huge, steamy, stinky dump on the suffering of polio’s victims in order to advance their anti-vaccine agenda.