Is Germ Theory a Myth?

by Ashley Hamer Pritchard
March 17, 2026

This episode was sponsored by Jason R. Coombs

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In April 2020, a germ-theory denialist Facebook group called “Terrain Model Refutes Germ Theory” had less than 150 members — mostly people who believed that diseases aren’t caused by germs, but by an unhealthy internal “terrain.” Fast forward to six years later, and that group has grown to more than 52,000 members. Around the same time, a book called The Contagion Myth was published. It claimed that bacteria and viruses don’t cause disease, that COVID-19 was actually caused by 5G electromagnetic radiation, and that Louis Pasteur himself recanted germ theory on his deathbed.

This isn’t just fringe conspiracy theory anymore. These ideas are influencing public health policy through figures like US Health and Human Services Secretary Robert F. Kennedy Jr., who has promoted terrain theory concepts and now holds significant sway over American health institutions. So let’s examine the evidence that germ theory denialists use to make their case — and see if it holds up.

The Contagion Myth: An Introduction

The Contagion Myth was written by Thomas Cowan and Sally Fallon Morell. They’re the vice president and president, respectively, of the Weston A. Price Foundation, an alternative health organization that advocates for raw milk and “traditional” diets. Cowan is a physician who published a viral video about 5G causing COVID-19 that was pulled from YouTube for misinformation, and also lost his medical license the same year The Contagion Myth was published.

That year was 2020, a few months after the COVID-19 pandemic began, which ensured the book got significant attention in alternative health circles. Interestingly, it doesn’t seem like many people actually read the book — it never hit any bestseller lists, and it only has 350 reviews on Goodreads despite being 6 years old — but its ideas have proliferated far beyond its readership.

The book’s main thesis is that contagion does not exist. No one has ever proven that a disease has been caused by bacteria or a virus, and in fact, the presence of these so-called “pathogens” is the result of illness, not the cause.

To explain further, they use a metaphor about firefighters:

Bacteria are found at the site of disease for the same reason that firemen are found at the site of fires. Bacteria are the cleanup crew tasked with digesting and getting rid of dead and diseased tissues. Claiming that bacteria cause a certain disease is no more reasonable than claiming that firemen cause fires, especially as experimental evidence shows this to be false.

The Evidence

So what’s this experimental evidence they claim supports their theory? Most of it involves centuries-old studies that couldn’t find a smoking gun for the cause of a disease because of rudimentary equipment. The authors point out that Louis Pasteur never found a bacterial agent for rabies — never mind that it’s a virus, a type of pathogen that wasn’t discovered until three years after he died. The same went for polio, a virus scientists couldn’t actually “see” until the invention of the electron microscope, long after they’d developed a vaccine.

Those scientists proved the existence of these pathogens by purifying them from ill patients and injecting them into healthy animals, where they caused the same disease. The Contagion Myth contends that every one of those experiments was fraudulent: they all also contained some sort of poison or contaminated tissue, which is the real reason the lab animals got sick.

For example, Robert Koch received the Nobel Prize for proving that tuberculosis was an infectious disease. He did this by developing what became known as Koch's postulates: a set of criteria for proving that a microorganism causes a disease. First, isolate the organism from a sick patient. Second, grow it in pure culture. Third, inoculate a healthy animal with the pure culture and reproduce the disease. Fourth, re-isolate the same organism from the newly sick animal. Koch successfully applied this rigorous methodology to tuberculosis, anthrax, and cholera — which is why he won the Nobel Prize in 1905.

The authors claim he made no such discovery because the tissue samples he used in his injections weren’t pure — they say they were stained with a poisonous blue dye that both helped him see the bacteria and helped kill any animal injected with it. But as The Nature Institute’s Craig Holdredge and John McAlice point out, this was either a misunderstanding or a willful misreporting of Koch’s source material: yes, he used a blue stain to examine the tissue taken from animals with tuberculosis. But then he isolated the bacteria, grew them in petri dishes until he had pure bacterial cultures, and then inoculated experimental animals with them. There was no poison in those inoculations.

Fabrication, Misrepresentation, and Cherry-Picking

This is just one of many instances of misunderstood, misrepresented, or just fabricated information in the book. The most famous instance is that of Louis Pasteur’s “deathbed confession,” which isn’t original to the book but underpins its main argument. The story goes that in his final moments, Louis Pasteur uttered, "I was wrong. The germ is nothing. The terrain is everything." Terrain being the internal condition of the animal or person.

There is zero evidence Pasteur ever said this. Around the time of Pasteur's death, multiple books were written, both about his life and criticizing his work, yet the first time this quote appears in print is in 1956, with no citation. The quote was almost certainly invented decades after his death.

Fabricated quotes and misrepresented research form one pillar of the book's argument. Another pillar: cherry-picking real experiments that didn't work as expected. In the 1910s, a physician named Milton J. Rosenau sought to discover the cause of influenza during an outbreak that preceded the Spanish Flu of 1918. He had isolated the pathogen he believed was responsible, and carefully infected healthy volunteers using nasal drops. When they didn’t get sick, he tried again with a larger dose. And another. The participants never got sick. They even had sick patients breathe on the volunteers. Still no dice.

The authors say this proves that influenza isn’t spread from person to person. Instead, they point to the antennas that had been recently installed on military bases nearby. Which brings us to the next key argument of the book: illness can be caused by electromagnetic radiation.

The EMF Argument

The authors claim that each pandemic in history coincides with a new electrical technology: the 1889 flu followed telegraph installation worldwide, the 1918 Spanish flu came after radio antenna deployment during World War I, the 1957 Asian flu followed radar installation, and the 1968 Hong Kong flu followed satellite launches.

They argue electromagnetic fields, or EMFs, disrupt the body’s natural electrical systems, which influence blood coagulation, oxygen transport, and cellular energy production. For COVID-19 specifically, they claim symptoms like hypoxia and “electric feelings on the skin” match symptoms of electromagnetic sensitivity, and that the disease correlates geographically with 5G rollout. They make the specific claim that 5G transmitters at 60 GHz cause oxygen molecules to “split apart,” which makes them unusable for respiration.

This argument relies entirely on cherry-picked correlations while ignoring massive contradictory evidence. For one thing, major pandemics happened for millennia before the advent of electricity — the authors explain many of those as the result of comets causing electrical interference in the atmosphere, but don’t account for the many comet flybys that didn’t cause pandemics. And the geographic distribution of COVID-19 doesn’t match that of 5G deployment; it spread quickly in areas without 5G, and many early 5G cities had low infection rates.

And 5G does not “split” oxygen molecules. While oxygen molecules do absorb radiation at the same frequency of some 5G transmitters, this absorption just changes the molecule’s rotational energy state, and only temporarily. It’s still perfectly breathable.

And of course, we have evidence that disease spread is real. As I mentioned, scientists have demonstrated viral transmission by exposing healthy participants to purified pathogens — not vaccines dosed with poison or infected tissue — and those participants got sick. In the case of the Rosenau experiments where the participants didn’t get sick, it was the delivery method, not the basic science, that was wrong. We now know that nasal drops require hundreds of times more virus to infect a host than an aerosolized virus inhaled into the lungs, and the symptomatic patients who breathed on participants were likely well past their most contagious phase, which is usually before symptoms are present.

This pattern repeats throughout the book. The authors’ strategy is to freeze science at its 19th-century state and ignore everything learned since. They claim no disease has ever fulfilled Koch's postulates — ignoring that even Koch modified his own criteria when he discovered asymptomatic carriers, and that we now have updated molecular standards that modern diseases easily meet.

How We Know Germ Theory Is Real

The real-world results of germ theory speak for themselves. Smallpox killed 300 million people in the 20th century before vaccination eradicated it entirely in 1980 — the only human disease ever eliminated. Before antibiotics, bacterial diseases like pneumonia, sepsis, tuberculosis, and wound infections were often death sentences. Penicillin has saved an estimated 500 million lives by killing the bacteria that cause these diseases.

Life expectancy in the United States increased by more than 30 years during the 20th century, with 25 of those years attributed to advances in public health. In 1900, 30 percent of all deaths occurred among children under age five; by 1997, that number dropped to 1.4 percent. These advances happened because germ theory is real, and it’s what enabled us to fight the pathogens that were killing people.

Germ theory denialists say that it’s not the germ, it’s the “terrain,” as Pasteur supposedly said in that fabricated deathbed quote. In other words, bacteria and viruses don’t make you sick; poor nutrition, environmental toxins, and electromagnetic radiation weaken the body and cause it to produce disease symptoms. Modern medical science recognizes that general health is an important element in the progression of an individual illness, but it’s not either-or.

And in fact, for some diseases, like the 1918 Spanish flu, young people die at higher rates because their healthy bodies mount a greater immune defense that overreacts to the virus, leading to respiratory distress and death. Healthy college athletes have died from bacterial meningitis. Well-nourished children with no underlying health conditions have died from measles.

The Dangers of Germ Theory Denial

Two of those children died of measles in Texas in 2025. US Health and Human Services Secretary Robert F. Kennedy Jr. visited their community and claimed the children died because they were malnourished, saying “It’s very, very difficult for measles to kill a healthy person.” He promoted cod liver oil and vitamin A as treatments instead of encouraging vaccination. The US is now in the midst of the largest measles outbreak in the 26 years since the disease was declared eliminated.

But terrain theory isn’t just promoted by public figures. It spreads through communities where parents refuse antibiotics for their children's bacterial infections, convinced that "toxins" or poor nutrition is the real culprit. It's in Facebook groups where people are told their cancer is caused by emotional trauma or 5G radiation, not cellular mutations. It's in the Mennonite communities in Texas where measles is now endemic because vaccination rates are too low.

Some proponents of terrain theory subscribe to a softer, more socially acceptable version: the idea that germs exist, but only unhealthy people get seriously ill. Even that is dangerous because it blames the victim. When a healthy child dies from an infection, terrain theorists insist the child must have had some hidden weakness. This lets people feel safe in their refusal of vaccines while shifting responsibility for deaths onto the victims and their families.

The seductive part of terrain theory is that it contains a kernel of truth: your overall health matters. Nutrition, stress, environmental toxins, and immune function all play roles in whether you get sick and how severe that illness becomes. But modern medicine already knows this. Doctors don't ignore the "terrain" — they just also recognize that pathogens exist and cause disease.

The danger comes when people use terrain theory to reject proven interventions. Vaccines work. Antibiotics work. Germ theory gave us the tools to eradicate smallpox, eliminate polio from most of the world, and add decades to our lifespans. Pretending that germs don't exist doesn't make you healthier. It just makes you — and everyone around you — more vulnerable to diseases we know how to prevent.

Addendum: While the pandemic is often called the Spanish Flu due to early, uncensored reports from Spain that made it seem like the country was hit particularly hard, it's more accurate to call it the 1918 Influenza Pandemic, or the Great Influenza Pandemic. AHP

By Ashley Hamer Pritchard