Multiple times in recent weeks, people have posted some version of the same claim on my social media accounts: viruses don't exist. The comments usually arrive with a set of caveats — cell culture techniques don't count as evidence, electron microscopy is interpreted too liberally, the photographs are artifacts. This is a total absurdity.
The evidence for the existence of viruses is incontrovertible and manifold. In 1892, a Russian botanist named Dmitri Ivanovsky passed the sap from diseased tobacco plants through a Chamberland filter — a porcelain filter fine enough to trap every known bacterium — and the filtrate still caused disease. Something was passing through that no bacterium could. That was the first documented encounter with what we now call a virus. Over the following century, the evidence compounded and converged: electron microscopy visualized viral particles directly beginning in the 1930s; fluorescence microscopy tracked their movement through living cells in real time; cytopathic effect — the characteristic pattern of cell destruction that differs systematically by pathogen — became a diagnostic standard that clinicians use today. These are not interpretations. They are observations, replicated independently on every continent, across 130 years.
The reason scientific evidence is inadmissible in these discussions is not because it is weak. It is because the people making these arguments have pre-rejected the epistemological framework which includes the scientific method. In their wicked egalitarianism, no one's standpoint is closer to reality than anyone else's — a virologist peering through an electron microscope has no more claim to truth than the person who watched a YouTube video about it. To even call this an argument gives it too much respect. It is the complete flattening and destruction of the concept of expertise.
That philosophical infrastructure underlies what is now US health policy. RFK Jr., the current Secretary of Health and Human Services, overtly questions germ theory in favor of what he calls terrain theory — the claim that what we label infectious disease results not from external pathogens but from an unhealthy internal "terrain." This is not a new idea. It is miasma theory, the discredited framework that predates Pasteur's epoch-making development of germ theory. Sanitation does matter — it reduced infant mortality meaningfully, and no one disputes that. But sanitation explains declining death rates from cholera and typhoid. It does not explain the elimination of smallpox, the near-eradication of polio, why pediatric wards are no longer filled with children with Hib meningitis, the survival of children who would otherwise have died of Hib meningitis. Vaccines and antibiotics explain those. The terrain model cannot account for what Fleming found growing on that contaminated petri dish, or what Jenner observed when the milkmaid who'd had cowpox didn't contract smallpox.
For many adherents of this worldview, infectious disease expertise (even when discussing a non-communicable disease) is inseparable from social control. Public health becomes not a response to pathogens but a mechanism of coercion. In this framing, outbreaks justify restrictions, experts become instruments of (bio)power, and skepticism itself becomes a form of resistance. The field of infectious disease medicine has been recast as a psyop designed to implement an agenda of social control. They respond with what the philosopher Foucault called counter-conduct: not just rejecting medical authority but appropriating its language — informed consent, bodily autonomy, "do your own research" — while treating ivermectin as a tribal symbol and any pathogen as a pretext for political theater.
I wonder whether they would have discouraged Jenner, Pasteur, Koch, and Fleming from trying to solve the human problems that infectious diseases posed. These were not agents of control. They were scientists who looked at people dying of preventable diseases and refused to accept it as the natural order of things.
D.A. Henderson's smallpox eradication campaign was not an act of biopower. It was an act of human reason applied to a significant and deadly human problem. That is what infectious disease medicine is — and has always been. Germ theory is not a narrative. It is a description of reality. As an infectious disease physician, I have treated patients with illnesses whose course changed because germ theory was true: bacterial infections halted by antibiotics, opportunistic infections prevented with antimicrobials, diseases made rare by vaccines. My field has always fought for civilization by trying to master an inhospitable natural world (as it always has) — it now faces an anti-human attack wielded by an army of postmodern nihilists who have been granted government power.