who discovered that infectious disease was spread by bacteria
Germ theory of disease The germ theory was proposed by Girolamo Fracastoro in 1546, and expanded upon by Marcus von Plenciz in 1762. Such views were held in disdain, however, and Galen's miasma theory remained dominant among scientists and doctors. The nature of this doctrine prevented them from understanding how diseases actually progressed, with predictable consequences. By the early nineteenth century, smallpox vaccination was commonplace in Europe, though doctors were unaware of how it worked or how to extend the principle to other diseases. Similar treatments had been prevalent in India from just before AD 1000.[2] [N 1] A transitional period began in the late 1850s with the work of Louis Pasteur. This work was later extended by Robert Koch in the 1880s. By the end of the 1880s the miasma theory was struggling to compete with the germ theory of disease. Eventually, a "golden era" of bacteriology ensued, during which the theory quickly led to the identification of the actual organisms that cause many diseases.[3][4] Viruses were discovered in the 1890s.
History of syphilis It was observed that sometimes patients who developed high fevers were cured of syphilis[by whom?]. Thus, for a brief time malaria was used as treatment for tertiary syphilis because it produced prolonged and high fevers (a form of pyrotherapy). This was considered an acceptable risk because the malaria could later be treated with quinine, which was available at that time. Malaria as a treatment for syphilis was usually reserved for late disease, especially neurosyphilis, and then followed by either Salvarsan or Neosalvarsan as adjuvant therapy. This discovery was championed by Julius Wagner-Jauregg,[44] who won the 1927 Nobel Prize for Medicine for his discovery of the therapeutic value of malaria inoculation in the treatment of neurosyphilis. Later, hyperthermal cabinets (sweat-boxes) were used for the same purpose.[45] These treatments were finally rendered obsolete by the discovery of penicillin, and its widespread manufacture after World War II allowed syphilis to be effectively and reliably cured.[46]