Uploaded December 2025 | Updated September 2026, 2 weeks ago

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People have been trying to prevent the spread of infectious disease forever, yet we only got germ theory in the 19th century. Except for one 16th century Italian doctor, who got it exactly right and was immediately forgotten. This video was inspired by Air-Borne: The Hidden History of the Life We Breathe, a new book by Carl Zimmer. If you’d like to check it out, head to bookshop.org/lists/scishow-recommended-reading. Made in partnership with The Alfred P. Sloan Foundation.

Sources:
Air-borne, by Carl Zimmer
scientificamerican.com/article/the-physician-who-presaged-the-germ-theory-of-disease-nearly-500-years-ago
ncbi.nlm.nih.gov/books/NBK24649
encyclopedia.com/people/medicine/medicine-biographies/girolamo-fracastoro
ebsco.com/research-starters/consumer-health/fracastoro-discovers-contagion-spreads-disease
taylorandfrancis.com/knowledge/Medicine_and_healthcare/Miscellaneous/Miasma_theory
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