Editing Leptospirosis (section)

==History==
The disease was first described by [[Adolf Weil (physician)|Adolf Weil]] in 1886 when he reported an "acute infectious disease with enlargement of spleen, jaundice, and [[nephritis]]."<ref name="Weil" /> Before Weil's description, the disease was known as "rice field [[jaundice]]" in ancient Chinese text, "autumn fever", "seven-day fever",<ref name="Ben Adler 2015"/> and "''nanukayami'' fever"<ref name="Elsevier/Saunders">{{cite book|title=Dorland's illustrated medical dictionary|year=2012|publisher=[[Elsevier/Saunders]]|location=Philadelphia|isbn=9781455709854|page=1231|url=https://books.google.com/books?id=mNACisYwbZoC&pg=PA1231|access-date=21 February 2016|archive-url=https://web.archive.org/web/20170908221631/https://books.google.com/books?id=mNACisYwbZoC&pg=PA1231|archive-date=8 September 2017|url-status=live}}</ref> in Japan; in Europe and Australia, the disease was associated with certain occupations and given names such as "cane-cutter's disease", "swine-herd's disease", and "''Schlammfieber''" (mud fever).<ref name="Ben Adler 2015">{{cite journal | vauthors = Adler B | title = History of leptospirosis and leptospira | journal = Current Topics in Microbiology and Immunology | volume = 387 | pages = 1–9 | date = 2015 | pmid = 25388129 | doi = 10.1007/978-3-662-45059-8_1 | isbn = 978-3-662-45058-1 }}</ref> It has been known historically as "black jaundice",<ref>{{cite book|title=Small Water Supplies: A Practical Guide|year=2004|publisher=[[Routledge]]|isbn=9781134457496|page=125|url=https://books.google.com/books?id=N1uBAgAAQBAJ&pg=PA125| first = David | last = Clapham | name-list-style = vanc |access-date=21 February 2016|archive-url=https://web.archive.org/web/20170908221631/https://books.google.com/books?id=N1uBAgAAQBAJ&pg=PA125|archive-date=8 September 2017|url-status=live}}</ref> or "dairy farm fever" in New Zealand.<ref>{{cite journal | vauthors = Christmas BW, Tennent RB, Lindsay PG | title = Dairy farm fever in New Zealand: a local outbreak of human leptospirosis | journal = The New Zealand Medical Journal | volume = 79 | issue = 514 | pages = 901–4 | date = May 1974 | pmid = 4527727 }}</ref> Leptospirosis was postulated as the cause of an epidemic among [[Native Americans in the United States|Native Americans]] along the coast of what is now [[New England]] during 1616–19. The disease was most likely brought to the [[New World]] by Europeans.<ref>{{cite journal | vauthors = Marr JS, Cathey JT | title = New hypothesis for cause of epidemic among native Americans, New England, 1616-1619 | journal =  [[Emerging Infectious Diseases (journal)|Emerging Infectious Diseases]] | volume = 16 | issue = 2 | pages = 281–6 | date = February 2010 | pmid = 20113559 | pmc = 2957993 | doi = 10.3201/eid1602.090276 }}</ref>

''Leptospira'' was first observed in 1907 in a [[post mortem]] kidney tissue slice by Arthur Stimson using [[Silver staining|silver deposition staining]] technique. He called the organism ''Spirocheta interrogans'' because the bacteria resembled a question mark.<ref name="Ben Adler 2015"/><ref>{{Cite journal | vauthors = Stimson AM | year = 1907 | title = Note on an organism found in yellow-fever tissue | journal = [[Public Health Reports]] | volume = 22 | page = 541 | url = https://babel.hathitrust.org/cgi/pt?id=umn.31951002763205f;view=1up;seq=551| doi = 10.2307/4559008 | issue = 18 | jstor = 4559008 }}</ref> In 1908, a Japanese research group led by Ryokichi Inada and Yutaka Ito first identified this bacterium as the causative agent of leptospirosis<ref>{{cite journal |vauthors=Inada R, Ito Y |title=A report of the discovery of the causal organism (a new species of spirocheta) of Weil's disease |journal=Tokyo Ijishinshi |volume=1915 |pages=351–60 |year=1908 }}</ref> and noted its presence in rats in 1916.<ref>{{cite journal | vauthors = Inada R, Ido Y, Hoki R, Kaneko R, Ito H | title = The Etiology, Mode of Infection, and Specific Therapy of Weil's Disease (Spirochætosis Icterohæmorrhagica) | journal = The Journal of Experimental Medicine | volume = 23 | issue = 3 | pages = 377–402 | date = March 1916 | pmid = 19867994 | pmc = 2125418 | doi = 10.1084/jem.23.3.377 }}</ref> Japanese coal mine workers frequently contracted leptospirosis. In Japan, the organism was named ''Spirocheta icterohaemorrhagiae''. The Japanese group also experimented with the first leptospiral immunisation studies in guinea pigs. They demonstrated that by injecting the infected [[guinea pig]]s with sera from convalescent humans or goats, [[passive immunity]] could be provided to the guinea pigs. In 1917, the Japanese group discovered rats as the carriers of leptospirosis.<ref name="Ben Adler 2015"/> Unaware of the Japanese group's work, two German groups independently and almost simultaneously published their first demonstration of transmitting leptospiral infection in guinea pigs in October 1915. They named the organism ''Spirochaeta nodosa'' and ''Spirochaeta Icterogenes'' respectively.<ref name="Ben Adler 2015"/>

Leptospirosis was subsequently recognised as a disease of all mammalian species. In 1933, Dutch workers reported the isolation of ''Leptospira canicola'' which specifically infects dogs. In 1940, the strain that specifically infects cattle was first reported in Russia.<ref name="Ben Adler 2015"/> In 1942, soldiers at [[Fort Bragg]], [[North Carolina]], were recorded to have an infectious disease which caused a rash over their [[shinbone]]s. This disease was later known to be caused by leptospirosis.<ref name="Haake 2015"/> By the 1950s, the number of serovars that infected various mammals had expanded significantly. In the 1980s, leptospirosis was recognised as a veterinary disease of major economic importance.<ref name="Ben Adler 2015"/>

In 1982, there were about 200 serovars of ''Leptospira'' available for classification. The [[International Committee on Systematic Bacteriology]]'s subcommittee on taxonomy of ''Leptospira'' proposed classifying these serovars into two big groups: ''L. interrogans'' containing pathogenic serovars and ''L. biflexa'' containing saprophytic serovars.<ref name="Ben Adler 2015"/> In 1979, the leptospiral family of ''Leptospiraceae'' was proposed. In the same year, ''Leptospira illini'' was reclassified as the new genus ''Leptonema''.<ref name="Ben Adler 2015"/> In 2002, "Lepthangamushi syndrome" was coined to describe a series of overlapping symptoms of leptospirosis with [[Hantavirus hemorrhagic fever with renal syndrome]], and [[scrub typhus]] caused by ''[[Orientia tsutsugamushi]]''.<ref>{{cite journal | vauthors = Paniz-Mondolfi AE, Rodriguez-Morales AJ, Blohm G, Marquez M, Villamil-Gomez WE | title = ChikDenMaZika Syndrome: the challenge of diagnosing arboviral infections in the midst of concurrent epidemics | journal = Annals of Clinical Microbiology and Antimicrobials | volume = 15 | issue = 1 | pages = 42 | date = July 2016 | pmid = 27449770 | pmc = 4957883 | doi = 10.1186/s12941-016-0157-x }}</ref><ref>{{cite web |title=284184004: Lepthangamushi syndrome (disorder) |url=http://tx.fhir.org/r3/snomed/32506021000036107/?type=snomed&id=284184004 |access-date=18 November 2019 |archive-url=https://web.archive.org/web/20191118153525/http://tx.fhir.org/r3/snomed/32506021000036107/?type=snomed&id=284184004 |archive-date=18 November 2019}}</ref> In 2005, ''Leptospira parva'' was classified as ''Turneriella''.<ref name="Ben Adler 2015"/> With [[DNA-DNA hybridisation]] technology, ''L. interrogans'' was divided into seven species. More ''Leptospira'' species have been discovered since then.<ref name="Ben Adler 2015"/> The WHO established the Leptospirosis Burden Epidemiology Reference Group (LERG) to review the latest disease epidemiological data of leptospirosis, formulate a disease transmission model, and identify gaps in knowledge and research. The first meeting was convened in 2009. In 2011, LERG estimated that the global yearly rate of leptospirosis is five to 14 cases per 100,000 population.<ref name="Haake 2015"/>