Functional Health Patterns - M. Gorden

Nursing theories

open access articles on nursing theories and models

Germ Theory of Disease


  • Germ theory states that specific microscopic organisms are the cause of specific diseases.

  • Germ theory is also called the pathogenic theory of medicine.

  • Germ theory led in to the development of antibiotics and hygienic practices.

  • It is considered as the cornerstone of modern medicine and clinical microbiology.

  • Major contributors to germ theory are:

    • Antoni van Leeuwenhoek
    • Francesco Redi
    • Rudolf Virchow
    • Louis Pasteur
    • Joseph Lister
    • Robert Koch


  • Microbes, or microorganisms - minute living things that are usually unable to be viewed with the naked eye.

  • Germ - refers to a rapidly growing cell.

  • Spontaneous generation - the hypothesis that living organisms arise from nonliving matter. It was an important early development in the germ theory.

  • Biogenesis:  living cells can arise only from preexisting cells.

  • Antibiotics - chemicals produced by bacteria and fungi that inhibit or kill other microbes.

Major Concepts

  • Explains the phenomenon of disease transmission

  • Means of speculative explanation and prediction of certain observable events

  • Allows us to effectively function to prevent transmission of communicable disease.

  • Viable basis upon which to make decisions about how to prevent certain illnesses.

  • There are phenomena we do not understand that are related to germ transmission, e.g. the communicability of cancer.

Antoni van Leeuwenhoek (1673-1723)
  • Microorganisms were first directly observed by Antoni van Leeuwenhoek, who is considered the father of microbiology.

Edward Jenner
  • In 1796, Edward Jenner inoculated a person with cowpox virus.
Agostino Bassi (1835)
  • Agostino Bassi showed a silkworm disease was caused by a fungus.
Ignaz Semmelwise (1840)
  • He advocated hand washing to prevent transmission of puerperal fever from one patient to another.
Louis Pasteur
  • Louis Pasteur was one of the first to link germs to disease.

  • In 1861, Louis Pasteur demonstrated that microorganisms are present in the air.

  • Pasteur discovered vaccines for chicken cholera. (1880), Anthrax (1881) and Rabies (1885).

  • Pasteur also showed that microbes are responsible for fermentation.

Joseph Lister
  • Joseph Lister is considered as inventor of antiseptic surgical techniques.

  • In 1860s, Joseph Lister used a chemical disinfectant to prevent surgical wound infections.

Robert Koch
  • In 1876, Robert Koch explained a bacterium causes anthrax.

  • In 1882, he discovered the germ that caused tuberculosis. (TB)

  • In 1883, he discovered the germ that caused cholera.

Alexander Fleming
  • In 1928, Alexander Fleming discovered the first antibiotic from Penicillium fungus.


  1. "The History of the Germ Theory". The British Medical Journal 1 (1415): 312. 1888.

  2. Germ Theory in Contagion: Historical Views of Diseases and Epidemics. Harvard University Library; accessed on 8/9/2011. Available at
This page was last updated on: 05/12/2020