Editing 1846–1860 cholera pandemic (section)

== 1850s ==
{{See also|1850s}}
The cholera epidemic in Russia that started in 1847 would last until 1851, killing over one million people. In 1851, a ship coming from Cuba carried the disease to [[Gran Canaria]].<ref>[http://coloquioscanariasamerica.casadecolon.com/index.php/CHCA/article/viewFile/9072/8523 HISTORICAL GEOGRAPHICAL APPROACH IN THE BEHAVIOR OF THE EPIDEMIC OF THE CHOLERA MORBUS OF 1851 IN THE PALMS OF GREAT CANARY] p.626</ref> It is considered that more than 6,000 people died in the island during summer,<ref>[http://mdc.ulpgc.es/cdm/ref/collection/MDC/id/44370 Historia de la medicina en Gran Canaria] pp.&nbsp;545–546</ref> out of a population of 58,000.

In 1852, cholera spread east to Indonesia, and later was carried to [[China]] and Japan in 1854. The [[Philippines]] were infected in 1858 and [[Korea]] in 1859. In 1859, an outbreak in Bengal contributed to transmission of the disease by travelers and troops to [[Iran]], [[Iraq]], [[Arabia]] and Russia.<ref name="Pandemic2"/> Japan suffered at least seven major outbreaks of cholera between 1858 and 1902. Between 100,000 and 200,000 people died of cholera in [[Tokyo]] in an outbreak in 1858–60.<ref>''[https://books.google.com/books?id=2Ps-IesBlzkC&pg=PA313&dq&hl=en#v=onepage&q=&f=false Kaoru Sugihara, Peter Robb, Haruka Yanagisawa, ''Local Agrarian Societies in Colonial India: Japanese Perspectives''], (1996), p. 313.''</ref>

In 1854, an outbreak of cholera in [[Chicago]] took the lives of 5.5 percent of the population (about 3,500 people).<ref name="Rosenberg2">{{cite book|title=The cholera years: the United States in 1832, 1849 and 1866|first=Charles E. | last=Rosenberg|author-link=Charles E. Rosenberg|publisher=[[University of Chicago Press]]|year=1987|isbn=978-0-226-72677-9|location=Chicago}}</ref><ref>[http://www.jonathanriley.net/chicsrc.html#y1854_m07_d12 ''Chicago Daily Tribune''] {{Webarchive|url=https://web.archive.org/web/20090831183711/http://www.jonathanriley.net/chicsrc.html#y1854_m07_d12 |date=31 August 2009 }}, 12 July 1854</ref> [[Providence, Rhode Island]] suffered an outbreak so widespread that for the next thirty years, 1854 was known there as "The Year of Cholera."<ref name="ProJo">{{cite news |last1=McKenna |first1=Ray |title=My Turn: Ray McKenna: R.I. residents of 1854 would relate |url=https://www.providencejournal.com/opinion/20200419/my-turn-ray-mckenna-ri-residents-of-1854-would-relate |access-date=20 April 2020 |publisher=The Providence Journal |date=19 April 2020}}</ref> In 1853–54, London's epidemic claimed 10,739 lives.  In [[Spain]], over 236,000 died of cholera in the epidemic of 1854–55.<ref>{{Cite book|url=https://books.google.com/books?id=tzRwRmb09rgC&pg=PA369|title=Encyclopedia of Plague and Pestilence: from Ancient Times to the Present|last=Kohn|first=George C.|publisher=Infobase Publishing|year=2008|isbn=978-0-8160-6935-4|page=369}}</ref> The disease reached South America in 1854 and 1855, with victims in Venezuela and Brazil.<ref name="Encyclopedia2"/> During the third pandemic, Tunisia, which had not been affected by the two previous pandemics, thought Europeans had brought the disease. They blamed their sanitation practices. Some United States scientists began to believe that cholera was somehow associated with African Americans, as the disease was prevalent in the South in areas of black populations. Current researchers note their populations were underserved in terms of sanitation infrastructure, and health care, and they lived near the waterways by which travelers and ships carried the disease.<ref>{{cite book|title=Epidemics and Pandemics: Their Impacts on Human History|last=Hayes|first=J. N.|publisher=ABC-CLIO|year=2005|location=Santa Barbara, CA|pages=233}}</ref>

=== 1854 Broad Street cholera outbreak ===
{{Main|1854 Broad Street cholera outbreak}}
[[File:Snow-cholera-map-1.jpg|right|thumb|300x300px|Original map by John Snow showing the [[Cluster (epidemiology)|clusters]] of cholera cases in the London epidemic of 1854]]
The [[1854 Broad Street cholera outbreak]] was a severe [[outbreak]] of [[cholera]] that occurred in 1854 near Broad Street (now [[Broadwick Street]]) in the [[Soho]] district of [[London]], [[England]], and occurred during the third cholera pandemic. This outbreak, which killed 616 people, is best known for the physician [[John Snow]]'s study of its causes and his hypothesis that [[Germ theory of disease|germ-contaminated water]] was the source of [[cholera]], rather than particles in the air (referred to as "[[Miasma theory|miasma]]").<ref>{{Cite journal|last=Eyeler|first=William|date=July 2001|title=The changing assessments of John Snow's and William Farr's Cholera Studies|journal=Sozial- und Präventivmedizin|volume=46|issue=4|pages=225–32|doi=10.1007/BF01593177|pmid=11582849|s2cid=9549345}}</ref><ref name=":0">{{Cite journal|last1=Paneth|first1=N|last2=Vinten-Johansen|first2=P|last3=Brody|first3=H|last4=Rip|first4=M|date=1998-10-01|title=A rivalry of foulness: official and unofficial investigations of the London cholera epidemic of 1854.|journal=American Journal of Public Health|volume=88|issue=10|pages=1545–1553|doi=10.2105/ajph.88.10.1545|issn=0090-0036|pmc=1508470|pmid=9772861}}</ref>

Snow identified the source of an 1854 cholera outbreak as the public water pump on Broad Street (now [[Broadwick Street]]). Although his studies were not entirely conclusive, his advocacy convinced the local council to disable the Broad Street pump by removing its handle. Snow later used a [[Dot distribution map|dot map]] to illustrate the cluster of cholera cases around the pump. He also used statistics to illustrate the connection between the quality of the water source and cholera cases, showing that water was being delivered to the outbreak area from sewage-polluted sections of the [[Thames]], leading to an increased incidence of cholera. Snow's study was a major event in the history of public health and geography. It is regarded as one of the founding events of the science of [[epidemiology]].

This discovery came to influence [[public health]] and the construction of improved [[sanitation]] facilities beginning in the mid-19th century. Later, the term "[[focus of infection]]"  would be used to describe sites, such as the Broad Street pump, in which conditions are good for transmission of an infection. John Snow's endeavor to find the cause of the transmission of cholera caused him to unknowingly create a [[Blinded experiment|double-blind experiment]].