In the past as today, the marketing and money gets the eyes and ears. While truth goes ignored. Nurse Florence Nightingale knew well of claims of what is now called “germ theory”. Well before Louis Pasteur is claimed to have “discovered” it. Because the mistaken germ theory was a known theory well before Louis Pasteur was ever born. Sadly, this lie gained acceptance like so many others. But, Florence Nightingale put in writing her take on claims you get sick from a germ/virus/(whatever bogus title you choose). In 1860, in her book Notes on Nursing.

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Is it not living in a continual mistake to look upon diseases, as we do now, as separate entities, which must exist, like cats and dogs? instead of looking upon them as conditions, like a dirty and a clean condition, and just as much under our own control; or rather as the reactions of kindly nature, against the conditions in which we have placed ourselves.

I was brought up, both by scientific men and ignorant women, distinctly to believe that small-pox, for instance, was a thing of which there was once a first specimen in the world, which went on propagating itself, in a perpetual chain of descent, just as much as that there was a first dog, (or a first pair of dogs,) and that small-pox would not begin itself any more than a new dog would begin without there having been a parent dog.

Since then I have seen with my eyes and smelt with my nose small-pox growing up in first specimens, either in close rooms, or in overcrowded wards, where it could not by any possibility have been “caught,” but must have begun.

Nay, more, I have seen diseases begin, grow up, and pass into one another. Now, dogs do not pass into cats.

I have seen, for instance, with a little overcrowding, continued fever grow up; and with a little more, typhoid fever; and with a little more, typhus, and all in the same ward or hut.

Would it not be far better, truer, and more practical, if we looked upon disease in this light?

For disease, as all experiences hows, are adjectives, not noun substantives.

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Notes on Nursing – What it is, and what it is not, by Florence Nightingale (1860) First Edition, page 19