Editing Robert Koch (section)

===Cholera===
[[File:Robert Koch (Deutsche Cholera-Expedition in Ägypten 1884).jpg|thumb|left|Photograph of Koch (third from the right) and other members of the German Cholera Commission in Egypt, 1884]]
[[File:Professors Koch and Pfeiffer working in a laboratory, invest Wellcome L0030175.jpg|thumb|Koch (on the microscope) and his colleague [[Richard Friedrich Johannes Pfeiffer]] (standing) investigating cholera outbreak in Bombay, India ]]
In August 1883, the German government sent a medical team led by Koch to [[Alexandria, Egypt]], to investigate a cholera epidemic there.<ref>{{Cite journal|last=Howard-Jones|first=N.|date=1984|title=Robert Koch and the cholera vibrio: a centenary|journal=British Medical Journal|volume=288|issue=6414|pages=379–381|doi=10.1136/bmj.288.6414.379|pmc=1444283|pmid=6419937}}</ref> Koch soon found that the [[intestinal mucosa]] of people who died of cholera always had bacterial infection, yet could not confirm whether the bacteria were the causative pathogens. As the outbreak in Egypt declined, he was transferred to Calcutta (now [[Kolkata]]) India, where there was a more severe outbreak. He soon found that the river [[Ganges]] was the source of cholera. He performed autopsies of almost 100 bodies, and found in each bacterial infection. He identified the same bacteria from water tanks, linking the source of the infection.<ref name=":0" /> He isolated the bacterium in pure culture on 7 January 1884. He subsequently confirmed that the bacterium was a new species, and described as "a little bent, like a comma."<ref name=":32">{{Cite journal|last1=Lippi|first1=D.|last2=Gotuzzo|first2=E.|date=2014|title=The greatest steps towards the discovery of Vibrio cholerae|journal=Clinical Microbiology and Infection|volume=20|issue=3|pages=191–195|doi=10.1111/1469-0691.12390|pmid=24191858|doi-access=free}}</ref> His experiment using fresh blood samples indicated that the bacterium could kill red blood cells, and he hypothesized that some sort of poison was used by the bacterium to cause the disease.<ref name=":0" /> In 1959, Indian scientist [[Sambhu Nath De]] discovered this poison, the [[cholera toxin]].<ref>{{Cite journal|last1=Nair|first1=G. Balakrish|last2=Takeda|first2=Yoshifumi|date=2011|title=Dr Sambhu Nath De: unsung hero|journal=The Indian Journal of Medical Research|volume=133|issue=2 |pages=127|pmc=3089041|pmid=21415484}}</ref> Koch reported his discovery to the German Secretary of State for the Interior on 2 February, and published it in the ''Deutsche Medizinische Wochenschrift'' (''German Medical Weekly'') the following month.<ref>Koch, R. (20 March 1884) {{lang|de|2=[https://books.google.com/books?id=yY41AQAAMAAJ&pg=PA191 "Sechster Bericht der deutschen wissenschaftlichen Commission zur Erforschung der Cholera"]}} (Sixth report of the German scientific commission for research on cholera), ''{{lang|de|Deutsche medizinische Wochenscrift}}'' (German Medical Weekly), '''10''' (12):  191–192. On page 191, he mentions the characteristic comma shape of ''Vibrio cholerae'':  ''"{{lang|de|Im letzten Berichte konnte ich bereits gehorsamst mittheilen, dass an den Bacillen des Choleradarms besondere Eigenschaften aufgefunden wurden, durch welche sie mit aller Sicherheit von anderen Bakterien zu unterscheiden sind. Von diesen Merkmalen sind folgende die am meisten charakteristischen: Die Bacillen sind nicht ganz geradlinig, wie die übrigen Bacillen, sondern ein wenig gekrümmt, einem Komma ähnlich.}}"'' (In the last report, I could already respectfully report that unusual characteristics were discovered in the bacteria of enteric cholera, by which they are to be distinguished with complete certainty from other bacteria. Of these features, the following are the most characteristic: the bacteria are not quite straight, like the rest of the bacilli, but a little bent, similar to a comma.)</ref>

Although Koch was convinced that the bacterium was the cholera pathogen, he could not entirely establish critical evidence the bacterium produced the symptoms in healthy subjects (following [[Koch's postulates]]). His experiment on animals using his pure bacteria culture did not cause the disease, and correctly explained that animals are immune to human pathogen. The bacterium was then known as "the comma bacillus", and scientifically as ''Bacillus comma''.<ref>{{Cite journal|last1=Winslow|first1=C. E.|last2=Broadhurst|first2=J.|last3=Buchanan|first3=R. E.|last4=Krumwiede|first4=C.|last5=Rogers|first5=L. A.|last6=Smith|first6=G. H.|date=1920|title=The Families and Genera of the Bacteria: Final Report of the Committee of the Society of American Bacteriologists on Characterization and Classification of Bacterial Types|journal=Journal of Bacteriology|volume=5|issue=3|pages=191–229|doi=10.1128/JB.5.3.191-229.1920|pmc=378870|pmid=16558872}}</ref> It was later realised that the bacterium was already described by an Italian physician [[Filippo Pacini]] in 1854,<ref>See:
* Fillipo Pacini (1854) {{lang|it|2=[https://books.google.com/books?id=xdtQAAAAcAAJ&pg=PA397 "Osservazioni microscopiche e deduzioni patologiche sul cholera asiatico"]}} (Microscopic observations and pathological deductions on Asiatic cholera), ''{{lang|it|Gazzetta Medica Italiana:  Toscana}}'', 2nd series, '''4'''(50):397–401; '''4'''(51):405–12.
* Reprinted (more legibly) as a [https://books.google.com/books?id=F9s_AAAAcAAJ&pg=PA1 pamphlet.]</ref> and was also observed by the [[Catalonia|Catalan]] physician Joaquim Balcells i Pascual around the same time.<ref name="Real Academia de la Historia 2018">{{cite web|year=2018|editor=Real Academia de la Historia|editor-link=Real Academia de la Historia|title=Joaquín Balcells y Pasqual|url=http://dbe.rah.es/biografias/18541/joaquin-balcells-y-pasqual|archive-url=https://web.archive.org/web/20190708211444/http://dbe.rah.es/biografias/18541/joaquin-balcells-y-pasqual|archive-date=8 July 2019|access-date=1 August 2020|language=es}}</ref><ref>{{cite web|year=2015|editor=Col·legi Oficial de Metges de Barcelona|editor-link=:ca:Col·legi Oficial de Metges de Barcelona|title=Joaquim Balcells i Pascual|url=http://www.galeriametges.cat/galeria-fitxa.php?icod=EGMM|archive-url=https://web.archive.org/web/20200801110910/http://www.galeriametges.cat/galeria-fitxa.php?icod=EGMM|archive-date=1 August 2020|access-date=1 August 2020|language=ca}}</ref> But they failed to identify the bacterium as the causative agent of cholera. Koch's colleague [[Richard Friedrich Johannes Pfeiffer]] correctly identified the comma bacillus as Pacini's ''vibrioni'' and renamed it as ''[[Vibrio cholerae|Vibrio cholera]]'' in 1896.<ref name=":42">{{Cite book|last=Hugh|first=Rudolph|url=https://books.google.com/books?id=NP7AY38J1hcC|title=Public Health Service Publication|date=1965|publisher=U.S. Department of Health, Education, and Welfare, Public Health Service, Environmental Health Service, National Air Pollution Control Administration|pages=1–4|language=en|chapter=Nomenclature and taxonomy of Vibrio cholerae Pacini 1854 and Vibrio eltor Pribam 1933}}</ref>