Basic forms of germ theory were proposed in the Middle Ages by physicians such as Ibn Sina, Ibn Khatima and Ibn al-Khatib, Girolamo Fracastoro in 1546, and expanded upon by Marcus von Plenciz in 1762. However such views were held in disdain in Europe, where Galen's miasma theory remained dominant among scientists and doctors.
By the early 1800s smallpox vaccination was common in Europe though doctors were unaware of how it worked or how to extend the principle to other diseases. A transitional period began in the late 1850s with the work of Louis Pasteur. By the end of the 1800s the miasma theory was struggling to compete with the germ theory of disease.
Agostino Bassi was the first person to prove that a disease was caused by a microorganism when his experiments between 1808 and 1813 demonstrated that a "vegetable parasite" caused a disease in silkworms known as calcinaccio. The "vegetable parasite" is now known to be a fungus pathogenic to insects called Beauveria bassiana.
Ignaz Semmelweis, anobstetrician working at theVienna General Hospital in 1847, noticed the high maternal mortality frompuerperal feverfollowing births assisted by doctors and medical students. However, those attended bymidwiveswere relatively safe. Investigating further Semmelweis made the connection between puerperal fever and examinations of delivering women by doctors and realized that these physicians had usually come directly fromautopsies. Asserting that puerperal fever was acontagious diseaseand that matter from autopsies was the cause he made doctors wash their hands with chlorinated lime water before examining pregnant women. He then documented a reduction in the mortality rate from 18% to 2.2% over one year. Despite this he and his theories wererejectedby most of the contemporary medical establishment.
By the early 1800s smallpox vaccination was common in Europe though doctors were unaware of how it worked or how to extend the principle to other diseases. A transitional period began in the late 1850s with the work of Louis Pasteur. By the end of the 1800s the miasma theory was struggling to compete with the germ theory of disease.
Agostino Bassi was the first person to prove that a disease was caused by a microorganism when his experiments between 1808 and 1813 demonstrated that a "vegetable parasite" caused a disease in silkworms known as calcinaccio. The "vegetable parasite" is now known to be a fungus pathogenic to insects called Beauveria bassiana.
Ignaz Semmelweis, anobstetrician working at theVienna General Hospital in 1847, noticed the high maternal mortality frompuerperal feverfollowing births assisted by doctors and medical students. However, those attended bymidwiveswere relatively safe. Investigating further Semmelweis made the connection between puerperal fever and examinations of delivering women by doctors and realized that these physicians had usually come directly fromautopsies. Asserting that puerperal fever was acontagious diseaseand that matter from autopsies was the cause he made doctors wash their hands with chlorinated lime water before examining pregnant women. He then documented a reduction in the mortality rate from 18% to 2.2% over one year. Despite this he and his theories wererejectedby most of the contemporary medical establishment.
