If there’s one thing that those of us who have been struggling to counter medical misinformation, quackery, and antivaccine pseudoscience frequently encounter, it’s people, particularly medical professionals and scientists, who have a hard time believing us when we describe just how unscientific, pseudoscientific, and just plain conspiracy-addled various beliefs underlying alternative medicine and antivaccine pseudoscience are. Surely, they seem to think, there’s no way anyone could actually believe that in 2021! How wrong they are! And it’s not as though such beliefs aren’t right there, in plain sight, for anyone who’s willing to take even a little time to look into various questions. Among the alternative medicine beliefs that provoke the most disbelief among my colleagues (and among educated lay people) is germ theory denialism. After nearly a year of mass disruption and death caused by the COVID-19 pandemic, which has been caused by a novel coronavirus and resulted in the deaths of 350K people in the US alone (as of yesterday and still rapidly counting), there are still quacks, conspiracy theorists, and denialists who refuse to accept that the pandemic is due to a new virus that spread throughout the world because it was readily transmissible and new, meaning that the entire world was an immunologically naïve population for it.

Although I had been alluding to germ theory denialism for years before, a decade ago I wrote a post entitled “Germ theory denial: A major strain in “alt-med” thought“, and a couple of years earlier Harriet Hall had written a post entitled ‘“I Reject Your Reality” – Germ Theory Denial and Other Curiosities‘. Unfortunately, beginning in 2020 (and undoubtedly continuing into 2021 and even beyond) germ theory denial ceased to be a “curiosity” and became a major threat to public health and efforts to slow the spread of SARS-CoV-2, the coronavirus that causes COVID-19, as it supports resistance to public acceptance public health interventions, ranging from masks to “lockdowns” to vaccines against COVID-19. As we enter the second year of the COVID-19 pandemic and as the new year dawns, I thought it would be useful to revisit the topic in the context of a global pandemic. One part of this post will be familiar to those who read my not-so-super-secret other blog, but some repetition is necessary to try to put all of this in context and to answer the question: How on earth can people deny germ theory in the middle of a pandemic that’s resulting in such strain on hospitals in some parts of the US that there is a very real fear that the healthcare system will break down under the load of COVID-19 patients and be unable to care for not just COVID-19 patients but patients requiring emergency medical care for other life-threatening conditions?

Germ theory versus “terrain theory” in the 19th century

The first thing we should clarify is just what we mean by the “germ theory of disease”. In most texts and sources that I’ve read, the germ theory of disease is stated in a form that resembles, “Certain diseases are caused by the invasion of the body by microorganisms”. We could argue whether viruses count as microorganisms, but for purposes of the germ theory of infectious diseases, they do. (Most biologists do not consider viruses to be true living organisms, because they consist of nothing other than genetic material wrapped in a protein coat and lack the ability to reproduce without infecting the cell of an organism.) Of course, over the more than a century and a half since Louis Pasteur first refuted the idea of spontaneous generation of life and posited the hypothesis that microbes caused many diseases, and Joseph Lister demonstrated that using carbolic acid to sterilize the surgical field greatly decreased the rate of postoperative infections, what is known as germ theory has become more complex, but at its root it’s still the same: Microbes (bacteria, viruses, parasites, etc.) cause some diseases by attacking the body.

In order for you to understand where germ theory denial came from and why it remains a potent force in alternative medicine, it’s necessary to understand a little bit of the history behind germ theory. Most of us were taught in high school and college in basic biology courses how Louis Pasteur’s observations led him to formulate what is now known as the germ theory of infectious disease. What most of us were not taught (or, if we were, only as a very brief aside) were the other hypotheses to explain infectious disease that were competing at the time with Pasteur’s hypotheses. We might, however, have been exposed to ideas that predated Pasteur regarding infectious disease.

The fascinating thing about germ theory denialism is that, long before Pasteur, concepts resembling germ theory had been proposed. For example, it was written in the Atharvaveda, a sacred text of Hinduism, that there are living causative agents of disease, called the yatudhānya, the kimīdi, the kṛimi and the durṇama (see XIX.34.9). One of the earliest Western references to this latter theory appears in a treatise called On Agriculture by Marcus Terentius Varro in 36 BC. In it, there is a warning about locating a farm too close to swamps:

…and because there are bred certain minute creatures which cannot be seen by the eyes, which float in the air and enter the body through the mouth and nose and there cause serious diseases.

That certain infectious diseases are contagious and could spread from person to person or come from other sources was so obvious that various explanations of how such a thing could happen held sway over many centuries. One common idea was the miasma theory of disease, which stated that diseases such as cholera, chlamydia or the Black Death were caused by a miasma, which translates as “pollution” or “bad air”. Certainly it was a fairly trivial observation, even centuries ago, that some diseases spread through the air. It’s also long been recognized that other diseases could be spread through the water and in other ways. In any case, various ideas about how disease develops battled it out in various places over various times throughout the era of prescientific medicine. Many of these ideas involved various concepts of mystical “life energy” such as qi, whose ebbs and flows could be manipulated for therapeutic effect (as in acupuncture, for example). Other ideas involved differing concepts of “contamination”, in which miasmas or various other “poisons” somehow got into the body from the environment to cause disease. These ideas were not unreasonable in the context of their times because science did not yet exist in a form that could falsify them as hypotheses, nor had the technology yet been developed to identify microscopic causative agents of disease. Given that background, attributing some infectious diseases to “bad air” doesn’t seem so unreasonable.

The beauty of Pasteur’s work is that it provided an explanation for many diseases that encompassed the concepts of miasma and various other ideas that had preceded it. It should not be forgotten, however, that Pasteur was not the first to propose germ theory. Scientists such as Girolamo Fracastoro (who came up with the idea that fomites could harbor the seeds of contagion), Agostino Bassi (who discovered that the muscardine disease of silkworms was caused by a tiny parasitic organism, a fungus that was named Beauveria bassiana), Friedrich Henle (who developed the concepts of contagium vivum and contagium animatum), and others had proposed ideas similar to the germ theory of disease before Pasteur. Pasteur was, however, more than anyone else, the scientist who provided the evidence to show that the germ theory of disease was valid and useful and popularized the theory. Not that there were not competing ideas; for example, those of Claude Bernard and Antoine Béchamp, both of whom who postulated nearly the exact opposite of what Pasteur did: that microorganisms were not the cause of disease but rather the consequence of disease, that injured or diseased tissues produced them, and that it was the health of the organism that mattered, not the microorganisms. In other words, the “terrain” was all. Bernard, for example, described the milieu intérieur, the interstitial fluids regarded as an internal environment in which the cells of the body are nourished and maintained in a state of equilibrium, which he and others also called terrain.

Béchamp’s idea, known as the pleomorphic theory of disease, stated that bacteria change form (i.e., demonstrate pleomorphism) in response to disease. In other words, they arise from tissues during disease states. Béchamp further postulated that bacteria arose from structures that he called microzymas, which to him referred to a class of enzymes, that microzymas are normally present in tissues, and that their effects depended upon the cellular terrain. Ultimately, Pasteur’s theory won out over the ideas of Bernard and Béchamp, based on evidence, but Béchamp was influential in the 19th century, and, given the science and technology of the time, his hypothesis was not entirely unreasonable. It was, however, superseded by Pasteur’s germ theory of disease and Koch’s later work that resulted in Koch’s postulates. (More on Koch’s postulates later.)

Besides not fitting with the scientific evidence, Béchamp’s idea had nowhere near the explanatory and predictive power that Pasteur’s theory did. On the other hand, there is a grain of truth in Béchamp’s ideas. Specifically, it is true that the condition of the “terrain” (the body) does matter when it comes to infectious disease. Debilitated people cannot resist the invasion of microorganisms as well as strong, healthy people. There is a twist, though. The “terrain” can facilitate the harmful effect of microorganisms in unexpected ways. One well-known example is how certain strains of influenza (as in 1918 and H1N1) are more virulent in the young because the young mount a more vigorous immune response against them.

Pre-pandemic (and now), the predominant form of germ theory denialism appears to be a “softer” form of denialism, just as the predominant form of evolution denialism is not young earth creationism, but rather “intelligent design” (ID) creationism. True, there are still young earth creationists around, who state that the world is only 6,000 years old and that the creatures that exist now were put there by God in their current state, but most denialists of evolutionary theory now accept that the earth is several billion years old and that organisms do evolve. They simply deny that natural selection and other mechanisms encompassed in current evolutionary theory are sufficient to account for the complexity of life and instead postulate that there must be a “designer” guiding evolution. Similarly, there are still some die-hard germ theory denialists out there who cite Béchamp in much the same way young earth creationists cite the Bible and deny that germs have anything to do with disease whatsoever, claiming instead that microbes appear “because of the terrain” and are an indicator, rather than a cause, of disease. However, most cases of germ theory denialism are of a piece with ID creationism. Like ID promoters who admit that evolution “does” happen, this variety of germ theory denialist accepts that microbes “can” cause disease, but they argue that microbes can only cause disease if the host is already diseased or debilitated. Using such claims, they argue that the “terrain” is by far the most important determinant of whether or not a person gets sick. As a result, they claim that eating the right diet, doing the right exercises, and taking the right supplements will protect you against disease as well as any vaccine — better, in fact, because supposedly you’re not injecting all those “toxins” from vaccines into your body.

Germ theory vs. "terrain theory"

This is the sort of silly analogy that germ theory deniers consider compelling. Dr. Gorski can only respond: Why not both? It’s not as though we don’t have to use just one (vaccines) or the other (sanitation, better diet, etc.). Science-based medicine uses anything that sciences shows to be effective and safe.

In alternative medicine, this invocation of 19th century ideas is very attractive, in that Bernard and Béchamp can be invoked to justify claims such as this:

Bernard, Bechamp, and their successors, proved that germs are not the actual root cause of sickness or disease… in reality, it is a weak terrain that is the ROOT CAUSE of sickness and disease.

A “weak terrain” is naturally more vulnerable to germs, so it needs to be built up through:

  • maximizing our nutritional status
  • minimizing our toxicity status, i.e. detoxification
  • maintaining a proper pH or acid/alkaline balance
  • maintaining a proper energetic/electrical balance

For this and other reasons Bechamp argued vehemently against vaccines, asserting that “The most serious disorders may be provoked by the injection of living organisms into the blood.” Untold numbers of researchers have agreed with him.

I can’t help but note that that “untold number” is very much near zero if you only include legitimate and competent scientists. I also can’t help but wonder how Béchamp could claim that injecting living organisms into the blood could provoke “the most serious disorders” even as he claimed that it was the “terrain”, not the microbes, that was responsible for disease. Also lacking from Béchamp’s ideas is how a “terrain”-based explanation of infectious disease could account for the obvious and long-observed fact that certain diseases could spread from person to person through the air, water, and fomites.

Germ theory denial even borrowed a page from conspiracy theories of all stripes, namely that of the “deathbed conversion” of the primary driver or originator of the conspiracy. In this case, there is a myth, parroted by people ranging from the antivaccine and HIV/AIDS-denying quack Kelly Brogan to Bill Maher to water fast guru Michael Klaper to functional medicine quack Dr. Mark Hyman, that Louis Pasteur “recanted” germ theory on his deathbed, reportedly saying, “Bernard avait raison. Le germe n’est rien, c’est le terrain qui est tout” (“Bernard is correct. The bacteria are nothing. The soil is everything”). In some versions of the telling, this statement is claimed to have been Pasteur’s last words right before he died, presumably because it’s a much more dramatic story that way. Guess what? As Peter Bowditch demonstrated in 2004, there is no evidence whatsoever that Pasteur ever said anything of the sort, either any time during his life or on his deathbed or as his last words. Moreover, the very first time this claim appears to have been published was in a 1976 revised edition of The Stress of Life by Hans Selye (although it might have been in the 1956 original edition). Selye, as I learned, was viewed as a pioneer in the study of how stress affects biology and susceptibility to disease and acknowledged the influence of Claude Bernard on his thinking; so it is perhaps not surprising that he might be attracted to an apocryphal story like that of Pasteur’s “deathbed conversion”. Selye’s apparent carelessness on this claim aside, right now, as I’ve said many times before, anyone who uses the myth that Louis Pasteur somehow “recanted” germ theory on his deathbed to justify ideas that lifestyle can make you virtually immune to disease has gone deep into germ theory denial, particularly if they also make claims like this one:

While Antoine Béchamp was a brilliant scientist with a remarkable mind, Louis Pasteur was very well-connected. So although the two researchers both studied disease pathology at the same point in time, it was Pateur’s connections which won him the financial backing to bring the germ theory mainstream.

Pasteur’s germ theory won mainstream attention in part because of his political and financial connections, and also because his views were in-line with the science and politics of the time. Additionally, the germ theory has paved the way for incredible pharmaceutical industry profit: chemotherapy, synthetic drugs, surgical removal of body parts, and vaccines have become society’s medicines of choice due to the groundwork laid by Pasteur–all very profitable.

The reason I want to revisit this moment is history is because although Pasteur’s germ theory has defined modern medicine–his theory has benefited scientific bias and insane industry profits–NOT public health.

It’s conspiracy theories all around, be they that of the “deathbed conversion” of Louis Pasteur or the claim that the only reason Pasteur’s theory ultimately won out over the ideas of Bernard and Béchamp is not because he was right but rather because his ideas were more profitable and he was politically well-connected. As I like to emphasize, science denialists always need a conspiracy theory to explain why science does not accept their preferred “alternative” ideas. Science denialism is thus always rooted in conspiracy theories.

You can see where I’m going with this in the age of COVID-19 and why pandemic deniers and minimizers might be attracted to the 19th century ideas of the “terrain” being more important than the “microbe,” namely for the same reason that antivaxxers so frequently lapse into germ theory denial and invoke Béchamp and/or Bernard. (Examples include Kelly Brogan and Andrew Wakefield) After all, if SARS-CoV-2 is not the “main” cause of COVID-19 and severe illness, then all those public health interventions, such as masking, “lockdowns,” and vaccines become superfluous and unnecessary, if not actively harmful. I’ll discuss this aspect more near the end of this post. I’ll also prime you by suggesting that, even if you’ve never heard of Claude Bernard, Antoine Béchamp, or “terrain theory” before, I bet you’ve encountered these ideas being invoked by quacks, antivaxxers, antimaskers, and anti-“lockdown” activists.

Germ theory denial in the age of the pandemic: SARS-CoV-2 is an exosome, not a virus!

There has really been no serious alternative hypothesis to explain infectious disease since the late 19th century, and, if anything, the intervening century and a half since germ theory was verified has only strengthened the hold. None of this has stopped the man who is arguably the most prolific promoter of the false idea that SARS-CoV-2 isn’t real and therefore this particular coronavirus can’t be the cause COVID-19, Dr. Andrew Kaufman, a psychiatrist who has essentially become a naturopath. Jonathan Jarry has described his tactics in general, which are common to his two major claims about COVID-19, very well:

In building a bridge between an observation and a conclusion he likes, he will often use valid science to lay down a number of planks. When that bridge is almost complete, he runs out of planks and takes a leap of faith, but that leap may only be noticeable by an expert.

This is actually a common tactic among science deniers. This particular science denier, Dr. Kaufman, describes himself thusly:

I am a natural healing consultant, inventor, public speaker, forensic psychiatrist, and expert witness. I completed my psychiatric training at Duke University Medical Center after graduating from the Medical University of South Carolina, and I have a B.S. from M.I.T. in Molecular Biology. I have conducted and published original research and lectured, supervised, and mentored medical students, residents, and fellows in all psychiatric specialties. I have been qualified as an expert witness in local, state, and federal courts. I have held leadership positions in academic medicine and professional organizations. I ran a start-up company to develop a medical device I invented and patented.

He also sends up a lot of red flags, for example:

Medicamentum Authentica means “authentic medicine” in Latin. This is the standard I ascribe to when I present health information and work with clients. Since word meanings are frequently changed, even inverted, by official dictionaries, Latin provides sanctuary. Since Latin is no longer spoken, it is considered a ‘dead language.’ Thus, its meanings will never be compromised.

Be very careful whenever you see a physician or other health practitioner using words like “true” and “authentic” with respect to medicine. These words bespeak a rather concrete worldview, in which only what they promote is “true” and “authentic”. The reference to Latin as a “dead language’ whose meanings will “never be compromised” is only a cherry on the top of the sundae of woo-speak. And Kaufman is definitely a germ theory denier. As Jarry notes:

Sounding composed and knowledgeable, Kaufman repeatedly tells his viewers that viruses are not a cause of human diseases. Through watching hours and hours of video, I have seen him deny the existence of the viruses behind the common cold, polio, HIV-AIDS, viral hepatitis, chickenpox, COVID-19, and measles.

Here’s the video in which he denies that viruses cause the common cold, polio, AIDS, chickenpox, and the measles. Because it’s nearly an hour and a half long, I have to commend Jarry for having suffered through it:

So what’s Kaufman’s alternative explanation? If you’ve followed this blog any length of time, you probably already know: “toxic exposures”, “malnutrition”, or the body’s “self-renewing” process or, in the case of polio, pesticides (nope).

And here’s the video where Kaufman denies that a virus causes COVID-19:

The key slides, screenshots from the video:

SARS-CoV-2 is an exosome?

Wow! Who can argue that the two look similar? That must mean they are the same thing; that is, only if you ignore all the other evidence that the SARS-CoV-2 coronavirus causes COVID-19.

COVID-19 is exosomes?

This was Kaufman’s first claim, namely that SARS-CoV-2, the coronavirus that causes COVID-19, is not a virus at all, but in fact exosomes that are removing the “toxins” that are the “real” cause of COVID-19. What are exosomes? In brief, they are small extracellular vesicles (like bubbles) that bud off from cells and can bump into and fuse with other cells. They were first discovered nearly 40 years ago:

The presence of membranous vesicles outside cells was first recognized 50 years ago, although these were originally assumed to be waste products released via shedding of the plasma membrane. The recognition of what we now call exosomes didn’t come until 1983, from studies on the loss of transferrin during the maturation of reticulocytes into erythrocytes [1]. These studies showed, by following transferrin-gold conjugates through the endocytic system, that [intraluminal vesicles] generated in [multivesicular bodies] can be released to the extracellular space through fusion with the plasma membrane [2], although it was not until 1987 that the term ‘exosome’ was coined for them [3].

Even then, however, these extracellular vesicles were largely ignored, forgotten or, again, dismissed as a means of cellular waste disposal. It is only in the past decade that interest in exosomes has exploded, with a nearly tenfold increase in publications in as many years (115 in 2006, 1010 in 2015).

This review article on exosomes published last February is an excellent overview for those with sufficient science background. Briefly, exosomes are a kind of extracellular vesicle (EV):

Exosomes are EVs with a size range of ~40 to 160 nm (average ~100 nm) in diameter with an endosomal origin. Sequential invagination of the plasma membrane ultimately results in the formation of multivesicular bodies, which can intersect with other intracellular vesicles and organelles, contributing to diversity in the constituents of exosomes. Depending on the cell of origin, EVs, including exosomes, can contain many constituents of a cell, including DNA, RNA, lipids, metabolites, and cytosolic and cell-surface proteins. The physiological purpose of generating exosomes remains largely unknown and needs investigation. One speculated role is that exosomes likely remove excess and/or unnecessary constituents from cells to maintain cellular homeostasis. Recent studies reviewed here also indicate a functional, targeted, mechanism-driven accumulation of specific cellular components in exosomes, suggesting that they have a role in regulating intercellular communication.

Confusing the issue is the observation that after replication in the cell some viruses can hijack exosome biogenesis machinery to promote their dissemination, with new virus particles “budding off” from the infected cell in exosome-like envelopes. Here is a diagram from the same review article:

Another wrinkle is that exosomes and lipid nanoparticles resembling exosomes have been utilized for drug delivery. Indeed, the lipid nanoparticles that encompass the mRNA used in the Pfizer/BioNTech and Moderna COVID-19 vaccines resemble exosomes and fuse to the cell membrane to deliver their mRNA payloads.

In any event, Kaufman claims that what is seen on electron microscopy is not a coronavirus, much less SARS-CoV-2, but rather exosomes. It does beggar the imagination that so many virologists and electron microscopy would make such a fundamental mistake, but Kaufman does seem to be arguing that. Specifically, as Frank Visser points out, his argument really is as simple as observing that the coronavirus resembles an exosome plus adding the claim that what PCR is detecting is RNA in exosomes, not the coronavirus, as his slide above states. He also cherry picks a quote by an expert to support his claim that viruses are exosomes. Here’s what Kaufman says:

I happened to look into the virology literature and actually they also think that viruses and exosomes are possibly the same thing. This is James Hildreth, a very famous researcher and academic physician in the field of virology and HIV research [lists his many other credentials] and he wrote this paper with two of his colleages [sic] there, and what he said, and I quote, “the virus is fully an exosome in every sense of the word.” Now this was just a great confirmation of what I was already thinking. I was kind of blown away when I read this in a paper. Because this was one of the last papers I looked at. To find that they have come to the same conclusion really helped validate my opinion.”

This quote occurs in an article by William A. Wells about HIV and how the virus can hijack exosomes, but is unreferenced, and Visser couldn’t find it anywhere else. On Twitter, Professor Hildreth said:

In an interview in March, Prof. Hildreth also made it very clear that he considered COVID-19 to be caused by the coronavirus that had been shown to cause it.

As Jarry put it, this is what Kaufman’s claim that SARS-CoV-2 is not a virus but rather an exosome is really doing:

Going back to exosomes, most of what Kaufman says is true. Our body is made of cells, and you can imagine a cell like a soap bubble. An exosome is a tiny bubble that buds off from that soap bubble and starts floating around, maybe eventually fusing with another soap bubble.

These exosomes can carry payloads, like genetic material, and act as transporters inside our body, and they do look an awful lot like many viruses. In fact, sometimes a virus will infect a cell and an exosome containing the virus’ genetic material will bud off and go on to infect another cell, just like a viral particle would! But here we reach the end of our bridge. Two scientific experts discussed this issue in a YouTube video and concluded that “clearly, there are similarities between exosomes and the coronavirus but they are absolutely different in many aspects.” Kaufman takes a leap and claims the virus does not exist. It’s all exosomes.

This brings us to the abuse of Koch’s postulates by Kaufman and other COVID-19 deniers.

Germ theory denial in the age of the pandemic: Koch’s postulates

Jarry got it quite right when he characterized how Kaufman uses some accurate science to build to his denial of the coronavirus and then makes a leap. Another example is how Kaufman claims that SARS-CoV-2 does not fulfill Koch’s postulates as the cause for COVID-19. Here’s the video where he does it, in which he is interviewed by Sayer Ji, whom we’ve met a number of times before in the context of discussing his antivaccine propaganda, genetics denial, and mangling of overdiagnosis:

The video’s introduction states:

In this interview, Dr. Kaufman explores a new study published in NATURE which claims to establish COVID-19 related pathogenicity in an animal model, but which does not fulfill Koch’s postulates for germ theory, and may overtly misrepresent the truth. This, in fact, is not new, as many publications have claimed to isolate COVID-19 or prove its role in causing animal and human deaths, yet none of them are actually capable of demonstrating this conclusively. Sayer Ji asks hard hitting questions and together they explore the implications of this and other research to the ongoing weaponization of germ theory as a political weapon for mass control and surveillance in violation of basic human, civil, constitutional and medical rights.

Note how the language gives away the game: “Weaponization of germ theory as a political weapon for mass control and surveillance”. Ji even introduces Kaufman with statements about how he is a “leader” in questioning how the “dominant narrative around COVID being this lethal invisible particle” that “sprung up in Wuhan in some kind of wet market” or was a “bioweapon” led to the “complete cessation” of social and economic activity, all based on what Ji characterizes as this “invisible particle” that’s been identified and is being tested everywhere. Particularly amusing is how Ji claims that Kaufman has been “telling the truth from the perspective of science itself”.

I’m not even going to go too much into the weeds of the video, because there’s so much misinformation, bad science, pseudoscience, and disinformation in the video that it would take a series of posts to deal with it, although I can point out that Jarry was very much right about Kaufman’s techniques of science denial and disinformation in terms of how he cherry picks papers and takes germs of reasonable science and concerns and twists them into weapons against germ theory that he uses to deny that SARS-CoV-2 has definitively been shown to be the cause of the COVID-19 pandemic. His core claim, which I’m going to zero in on, is that SARS-CoV-2 does not meet Koch’s postulates for causation of COVID-19.

First, let’s review Koch’s postulates, using the quote from Robert Koch from 1890 repeated on the website of a chiropractor hosting the video:

However, if it can be proved: first that the parasite occurs in every case of the disease in question, and under circumstances which can account for the pathological changes and clinical course of the disease; secondly, that it occurs in no other disease as a fortuitous and non­ pathogenic parasite; and thirdly, that it, after being fully isolated from the body and repeatedly grown in pure culture, can induce the disease anew…

Or, to boil Koch’s postulates down to a 1937 version by Thomas Rivers and colleagues:

  1. The parasite (virus) is present in every case of the disease.
  2. The parasite should be fully isolated from the body and all products of disease (i.e. purified)
  3. The parasite should be grown in a pure culture (not possible for viruses)
  4. The isolated parasite produces the same disease, with all of its characteristics, in a normal host

As is the case with “terrain theory”, I love to note how germ theory-denying quacks just love to cite 19th century understandings of infectious disease as the be-all and end-all of the science of infectious disease, as if science hasn’t advanced in 120 years! Ji and Kaufmann even cite a quote that Koch’s postulates have not been satisfied in viral diseases, leading to this quote about modification of Koch’s postulates for viruses:

… the spirit of his [Koch’s] rules of proof still holds in that a worker must demonstrate that a virus is not only associated with a disease but that is actually the cause… this is accomplished by the production with a degree of regularity of a transmissible infection in susceptible experimental hosts by means of inoculation of material, free from ordinary microbes or ricketssiae [sic], obtained from patients with the natural disease…

Again, Koch’s postulates arose from 19th century science and were proposed when germ theory was still in its infancy. We’ve learned since then that things are a lot more complicated, and, of course, quacks have been trying to point to examples of that complexity to cast doubt on the whole edifice of germ theory as the explanation for infectious diseases. The funny thing is that even in the 19th century Koch soon realized that there existed infectious diseases that did not fulfill his postulates. Thomas Rivers, viewed as the “father of modern virology” even wrote:

It is unfortunate that so many workers blindly followed the rules, because Koch himself quickly realized that in certain instances all the conditions could not be met… Thus, in regard to certain diseases, particularly those caused by viruses, the blind adherence to Koch’s postulates may act as a hindrance instead of an aid.

Today scientists recognize Koch’s postulates mainly for their historical importance rather than as hard-and-fast rules to demonstrate disease causation. As mentioned by Thomas Rivers above, even Koch started to loosen the requirements of some of his own postulates, for example:

Koch abandoned the requirement of the first postulate altogether when he discovered asymptomatic carriers of cholera and, later, of typhoid fever. Asymptomatic or subclinical infection carriers are now known to be a common feature of many infectious diseases, especially viruses such as polio, herpes simplex, HIV, and hepatitis C. Specifically, all doctors and virologists agree that the poliovirus causes paralysis in just a few infected subjects, and the success of the polio vaccine in preventing disease supports the conviction that the poliovirus is the causative agent.

Sound familiar? It is now known that SARS-CoV-2 can cause asymptomatic infections in a relatively high proportion of patients and that these asymptomatic people can transmit the virus. How large a driver of the pandemic asymptomatic spread is has been heatedly debated, but there is no doubt that you can have COVID-19 and have few or no symptoms. It is true that, early in the pandemic, the World Health Organization appeared to have stated that asymptomatic spread of COVID-19 was rare (it didn’t exactly say that), and it was soon forced to walk even that claim back rapidly.

Even the second of Koch’s postulates doesn’t always apply:

The second postulate may also be suspended for certain microorganisms or entities that cannot (at the present time) be grown in pure culture, such as prions responsible for Creutzfeldt–Jakob disease.

Ditto the third of Koch’s postulates:

The third postulate specifies “should”, not “must”, because as Koch himself proved in regard to both tuberculosis and cholera, that not all organisms exposed to an infectious agent will acquire the infection. Noninfection may be due to such factors as general health and proper immune functioning; acquired immunity from previous exposure or vaccination; or genetic immunity, as with the resistance to malaria conferred by possessing at least one sickle cell allele.

Again, does this sound familiar? Asymptomatic infection with SARS-CoV-2 occurs. A lot. Moreover, the virus can be grown in culture, just as many coronaviruses have been. It’s related to SARS, a coronavirus (hence its name), the coronavirus that was so feared in 2002-2003.

Another thing that Kaufman does in the video is to cherry pick studies to try to cast doubt on. For instance, he looks at the New England Journal of Medicine study published in January that first described the novel coronavirus isolated from patients with a mysterious new pneumonia in China in late 2019 that isolated virus from three patients in Wuhan. He harps on a statement in the conclusion of the paper:

Although our study does not fulfill Koch’s postulates, our analyses provide evidence implicating 2019-nCoV in the Wuhan outbreak. Additional evidence to confirm the etiologic significance of 2019-nCoV in the Wuhan outbreak include identification of a 2019-nCoV antigen in the lung tissue of patients by immunohistochemical analysis, detection of IgM and IgG antiviral antibodies in the serum samples from a patient at two time points to demonstrate seroconversion, and animal (monkey) experiments to provide evidence of pathogenicity.

Well, duh! It was January 2020. The outbreak in Wuhan was only a couple of months old. In fact, that paper was quite impressive for what the scientists could accomplish in that they isolated a new virus, sequenced its genome and related it to existing coronaviruses, and published highly suggestive evidence that this new coronavirus was the cause of the pneumonia observed.

Kaufman also tries to cast doubt on this study by pointing to the small sample size. Again, this study was preliminary evidence, not absolutely confirmatory, and there have been many, many studies since then confirming that this then-novel coronavirus is the cause of COVID-19. He also claims that there was “no virus particle directly from patient demonstrated or identified”. Note the word “directly”. The authors actually did culture the virus in human airway epithelial cells and Vero E6 and Huh-7 cell lines. Hilariously, Kaufman also claims that “short RNA sequences of unknown origin from BAL sample” were “not conclusive”. This is a misrepresentation of PCR methods used to amplify RNA from the virus taken from human respiratory isolates. He even dismisses, in essence, the computational biology behind next generation sequencing that has been used to sequence the virus as a “theoretical model of a theoretical virus”. He says he’s working on a white paper to claim this. He also dismisses next gen sequencing as being only good if you know what the sequence is already, which is utter nonsense. Of course, knowledge of existing coronavirus sequences was used to guide the sequencing of SARS-CoV-2, but that doesn’t mean that scientists didn’t correctly identify the virus. (I suspect that molecular biologists who deal with next gen sequencing would be face palming furiously, if they ever listened to this part.)

In fact, an update to Koch’s postulates based on advances over the prior 100 years in science, microbiology, virology, and nucleic acid sequencing was proposed in 1996 by Fredricks and Relman and were summarized thusly:

  1. A nucleic acid sequence belonging to a putative pathogen should be present in most cases of an infectious disease. Microbial nucleic acids should be found preferentially in those organs or gross anatomic sites known to be diseased, and not in those organs that lack pathology.
  2. Fewer, or no, copy numbers of pathogen-associated nucleic acid sequences should occur in hosts or tissues without disease.
  3. With resolution of disease, the copy number of pathogen-associated nucleic acid sequences should decrease or become undetectable. With clinical relapse, the opposite should occur.
  4. When sequence detection predates disease, or sequence copy number correlates with severity of disease or pathology, the sequence-disease association is more likely to be a causal relationship.
  5. The nature of the microorganism inferred from the available sequence should be consistent with the known biological characteristics of that group of organisms.
  6. Tissue-sequence correlates should be sought at the cellular level: efforts should be made to demonstrate specific in situ hybridization of microbial sequence to areas of tissue pathology and to visible microorganisms or to areas where microorganisms are presumed to be located.
  7. These sequence-based forms of evidence for microbial causation should be reproducible.

SARS-CoV-2 fulfills Koch’s postulates easily, as can be demonstrated by looking at the totality of evidence and not misrepresenting it, all while recognizing what PCR and next generation sequencing really are, rather than the simplistic, distorted view that Kaufman provides. In fact, I don’t even need to list all the examples myself here. In October Virology Down Under published an exhaustive list of studies showing that this coronavirus does, in fact, fulfill Koch’s postulates.

Of course, if the virus doesn’t exist and germ theory doesn’t explain an infectious disease like SARS-CoV-2, then why does Dr. Kaufman care if it fulfills Koch’s postulates or not? Inquiring minds want to know.

Germ theory denial in the age of the pandemic: The fringier fringe

While Dr. Kaufman is arguably the most persistent germ theory denier promoting disinformation about COVID-19, he’s not the only one. There are a number of deniers out there promoting even wilder ideas. For example:

Longtime readers will recognize this as nothing more than a variant of an idea that I first encountered when it was being promoted by über-quack Robert O. Young, who claims that viruses are “molecular acids” and denies that they cause disease:

The point being that viruses are molecular liquids or gases (venom) that can be created by chemical imbalances in humans, plants and animals (by malnutrition or toxic acidic food and/or drink consumption), also created in humans, plants and animal glands, sometimes used in defense (snake venom) or emergency (overactive adrenals), also can be crystallized in laboratories, rarely, if ever crystallized in vivo, and foolish to call viruses contagious when viruses are nothing more than acidic liquids or gases from biological transformation or rotting matter.

Basically, to Young, viruses are not real, bacteria do not cause sepsis, and cancer is “acid“, with the cancerous tumor being the body’s healthy reaction to eliminate the acidic “toxins”.

Then there is misinformation like this, as posted by Peter Bowditch:

I love the part complaining about how the electron micrographs of viruses are “blurry” is reason to believe that viruses don’t exist and can’t be imaged with electron microscopy. Obviously because images of molecules and atoms are similarly somewhat blurry that must mean that molecules and atoms don’t exist!

There’s also a lot of concrete thinking behind germ theory denial. The most prominent example is the tendency of deniers to claim that, because not everyone gets sick when they are exposed to a pathogen, it must mean that germ theory is invalid and terrain theory is a better explanation. I discussed this in my previous post on germ theory denial, for instance, the example of ten people go get on an elevator with a person with the flu who’s coughing all over the place. Everyone in the elevator is exposed to the flu virus, the argument goes, but not everyone gets the flu. Observations like this are referenced as though they were evidence that the germ theory is fatally flawed! Basically, germ theory denialists seem to think that anything less than a 100% infection and illness rate in people exposed to a pathogenic organism means that that organism doesn’t cause the disease, and don’t even get them started on asymptomatic transmission, as is common with SARS-CoV-2. It’s an example of all-or-nothing thinking that’s so prevalent in promoters of pseudoscience and is very much akin to how antivaccine zealots argue, in essence, that if a vaccine isn’t 100% effective and 100% safe it’s useless, just as if a PCR test for COVID-19 has a false positive rate and isn’t perfect then the pandemic is really a “casedemic” of false positives.

The attraction of “soft” germ theory denial in the age of COVID-19

Germ theory denial is not a new phenomenon. It’s been around as long as germ theory has and has long been a major strain in alternative medicine beliefs about disease. Pre-pandemic, the attractiveness is that “terrain” theory allowed its believers to labor under the delusion that, if only they ate the right foods, lived the right lifestyle, did the right things, and were, from a health standpoint, virtuous, they would be virtually immune to infectious disease. My favorite example occurred when Bill Maher claimed that his diet and lifestyle (but what about his copious use of weed?) meant that he couldn’t catch the flu on an airplane even if there were several people with the flu on the flight, to which Bob Costas retorted acidly (word choice intentional), “Oh, come on, Superman!” It’s all of a piece with what I like to call the Central Dogma of Alternative Medicine, namely that you have virtually 100% control over whether you get sick and if you just want to be healthy badly enough you will be.

Of course, as I said before, these days most germ theory denial is not absolute. Far more often, germ theory denial is “soft” in that it takes the form of a (usually weak) concession that microbes can under certain circumstances (basically only if the host is already sick) cause disease, but with the caveat that the disease is so much less likely to take hold or so much less likely to be deadly if you only live a virtuous life in terms of diet, exercise, and lifestyle; i.e., if you are Superman in terms of health. Unsurprisingly, it is the latter claim that nearly always overshadows the concession.

There is, of course, a grain of truth here in that debilitated people and people with comorbidities are far more likely to die of COVID-19 (for example), but in the hands of “soft deniers” of germ theory that grain of truth results in the delusion that they can’t get seriously sick from COVID-19 because they are so healthy and that they are thus not a danger to those who are particularly susceptible to coronavirus. This “soft” germ theory denial also leads to massive victim shaming, such as when Del Bigtree urged his listeners to “catch this cold” (COVID-19) to gain “natural immunity”, even as he blamed those at risk for death from coronavirus for having lived an unhealthy lifestyle that had put them at risk. It also leads to ideas that border on eugenics, such as the Great Barrington Declaration, which recommends basically letting COVID-19 rip through the “healthy” population while using “focused protection” to protect the vulnerable. Never mind that COVID-19 can kill the healthy and that it’s impossible to isolate the vulnerable from the virus while it’s spreading exponentially in the general population. Finally, this “soft” germ theory denial provides a reasonable-seeming pretext to oppose masks, any sort of “lockdown”, and, of course, vaccines.

A decade ago, germ theory denial was largely viewed as no more than a “curiosity,” a quirky idea held by few and likely not of much consequence or likely to cause much harm. Few other than those of us who recognized how such denial fueled the antivaccine movement recognized it as a problem. Unfortunately, the COVID-19 pandemic has made it very clear how deadly such ideas are.


Posted by David Gorski

Dr. Gorski's full information can be found here, along with information for patients. David H. Gorski, MD, PhD, FACS is a surgical oncologist at the Barbara Ann Karmanos Cancer Institute specializing in breast cancer surgery, where he also serves as the American College of Surgeons Committee on Cancer Liaison Physician as well as an Associate Professor of Surgery and member of the faculty of the Graduate Program in Cancer Biology at Wayne State University. If you are a potential patient and found this page through a Google search, please check out Dr. Gorski's biographical information, disclaimers regarding his writings, and notice to patients here.