Germ theory of disease
Ignaz SemmelweisLouis PasteurRobert KochJohn Snow
This page delivers no verdict; it presents claims and evidence with their sources. No theory in science is absolute. Method
For everyone
Until the mid-19th century many diseases were thought to spread through "bad air" (miasma). Semmelweis's hand-washing observations, Snow's cholera map, Pasteur's experiments and Koch's identification of the anthrax and tuberculosis bacteria established the view that specific microorganisms cause specific diseases.
For specialists
Koch (1876) grew Bacillus anthracis in pure culture and reproduced the disease. Koch's postulates set criteria for regarding a microorganism as the cause of a disease; asymptomatic carriers, unculturable agents and prions have shown their limits. In 1847 Semmelweis showed that washing hands with chlorinated lime sharply reduced deaths from puerperal fever, a finding largely rejected by his contemporaries.
Claims
- Each infectious disease is caused by specific microorganisms.[1]
Evidence
Supporting
Anthrax bacilli grown in pure culture produced the same disease when given to healthy animals.[1]
After hand-washing with chlorinated water was introduced, maternal mortality in the clinic fell from about 18% to below 2%.[2]
Challenging
Carriers, unculturable agents and prion diseases showed that Koch's postulates cannot be applied in every case.[3]
Connections
Sources
- Article (1876). Die Ätiologie der Milzbrand-Krankheit, begründet auf die Entwicklungsgeschichte des Bacillus Anthracis. Beiträge zur Biologie der Pflanzen 2, 277–310
- Book (1861). Die Ätiologie, der Begriff und die Prophylaxis des Kindbettfiebers. Hartleben, Pest–Wien–Leipzig
- Article (1996). Sequence-based identification of microbial pathogens: a reconsideration of Koch's postulates. Clinical Microbiology Reviews 9(1), 18–33DOI 10.1128/CMR.9.1.18archive
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Cite this page
Athena contributors. (2026). Germ theory of disease. Athena: The tree of human knowledge. Retrieved November 1, 2026, from https://latifkedi.github.io/athena/en/d/mikrop-kurami/
@misc{athena_mikrop_kurami,
title = {Germ theory of disease},
author = {{Athena contributors}},
year = {2026},
howpublished = {\url{https://latifkedi.github.io/athena/en/d/mikrop-kurami/}},
note = {Athena: The tree of human knowledge. Accessed: 2026-11-01}
}Added: September 27, 2026 · Last changed: September 27, 2026 · Page history