Editing Plasmodium falciparum (section)

== History ==
[[File:Laveran Malaria drawings.jpg|thumb|Laveran's drawing of various stages of ''P. falciparum'' as seen on fresh blood (1880).]]
Falciparum malaria was familiar to the [[ancient Greece|ancient Greeks]], who gave the general name {{lang|grc|πυρετός}} (''pyretós'') "fever".<ref>{{cite journal|last1=Baron|first1=Christopher|last2=Hamlin|first2=Christopher|title=Malaria and the Decline of Ancient Greece: Revisiting the Jones Hypothesis in an Era of Interdisciplinarity|journal=Minerva|date=2015|volume=53|issue=4|pages=327–358|doi=10.1007/s11024-015-9280-7|s2cid=142602810}}</ref> [[Hippocrates]] (c. 460–370 BCE) gave several descriptions on [[Fever#Types|tertian fever and quartan fever]].<ref name=":0">{{cite journal|last1=Hempelmann|first1=Ernst|last2=Krafts|first2=Kristine|title=Bad air, amulets and mosquitoes: 2,000?years of changing perspectives on malaria|journal=Malaria Journal|date=2013|volume=12|issue=1|pages=232|doi=10.1186/1475-2875-12-232|pmid=23835014|pmc=3723432 |doi-access=free }}</ref> It was prevalent throughout the ancient Egyptian and Roman civilizations.<ref>{{cite journal|last1=Nerlich|first1=Andreas|title=Paleopathology and Paleomicrobiology of Malaria|journal=Microbiology Spectrum|date=2016|volume=4|issue=6|pages=155–160|doi=10.1128/microbiolspec.PoH-0006-2015|pmid=27837743|isbn=9781555819163}}</ref> It was the Romans who named the disease "malaria"—''mala'' for bad, and ''aria'' for air, as they believed that the disease was spread by contaminated air, or [[miasma theory|miasma]].<ref name=":0" /><ref name="lalchhandama" />

===Discovery===
A German physician, [[Johann Friedrich Meckel]], must have been the first to see ''P. falciparum'' but without knowing what it was. In 1847, he reported the presence of black pigment granules from the blood and spleen of a patient who died of malaria. The French Army physician [[Charles Louis Alphonse Laveran]], while working at Bône Hospital (now [[Annaba]] in Algeria), correctly identified the parasite as a causative pathogen of malaria in 1880. He presented his discovery before the [[French Academy of Medicine]] in Paris and published it in ''[[The Lancet]]'' in 1881. He gave it the scientific name ''Oscillaria malariae''.<ref name=lalchhandama>{{cite journal|last1=Lalchhandama|first1=K.|title=The making of modern malariology: from miasma to mosquito- malaria theory|journal=Science Vision|date=2014|volume=14|issue=1|pages=3–17|url=http://www.sciencevision.org/current_issue/dl/Lalchhandama.pdf|url-status=dead|archive-url=https://web.archive.org/web/20140427025145/http://www.sciencevision.org/current_issue/dl/Lalchhandama.pdf|archive-date=2014-04-27}}</ref> However, his discovery was received with skepticism, mainly because by that time, leading physicians such as [[Edwin Klebs|Theodor Albrecht Edwin Klebs]] and [[Corrado Tommasi-Crudeli]] claimed that they had discovered a bacterium (which they called ''Bacillus malariae'') as the pathogen of malaria. Laveran's discovery was only widely accepted after five years when [[Camillo Golgi]] confirmed the parasite using better microscopes and staining techniques. Laveran was awarded the [[Nobel Prize in Physiology or Medicine]] in 1907 for his work. In 1900, the Italian zoologist [[Giovanni Battista Grassi]] categorized ''[[Plasmodium]]'' species based on the timing of fever in the patient; malignant tertian malaria was caused by ''Laverania malariae'' (now ''P. falciparum''), benign tertian malaria by ''Haemamoeba vivax'' (now ''[[Plasmodium vivax|P. vivax]]''), and quartan malaria by ''Haemamoeba malariae'' (now ''[[Plasmodium malariae|P. malariae]]'').<ref>{{cite journal|last1=Cox|first1=Francis EG|title=History of the discovery of the malaria parasites and their vectors|journal=Parasites & Vectors|date=2010|volume=3|issue=1|pages=5|doi=10.1186/1756-3305-3-5|pmid=20205846|pmc=2825508 |doi-access=free }}{{open access}}</ref>

The British physician [[Patrick Manson]] formulated the [[mosquito-malaria theory]] in 1894; until that time, malarial parasites were believed to be spread in air as miasma, a Greek word for pollution.<ref name=lalchhandama/> His colleague [[Ronald Ross]] of the Indian Medical Service validated the theory while working in India. Ross discovered in 1897 that malarial parasites lived in certain mosquitoes. The next year, he demonstrated that a malarial parasite of birds could be transmitted by mosquitoes from one bird to another. Around the same time, Grassi demonstrated that ''P. falciparum'' was transmitted in humans only by female [[Anopheles|anopheline mosquito]] (in his case ''[[Anopheles claviger]]'').<ref>{{cite journal|last1=Baccetti|first1=B|title=History of the early dipteran systematics in Italy: from Lyncei to Battista Grassi|journal=Parassitologia|date=2008|volume=50|issue=3–4|pages=167–172|pmid=20055226}}</ref> Ross, Manson and Grassi were nominated for the Nobel Prize in Physiology or Medicine in 1902. Under controversial circumstances, only Ross was selected for the award.<ref>{{cite journal|last1=Capanna|first1=E|title=Grassi versus Ross: who solved the riddle of malaria?|journal=International Microbiology|date=2006|volume=9|issue=1|pages=69–74|pmid=16636993}}</ref>

There was a long debate on the taxonomy. It was only in 1954 the [[International Commission on Zoological Nomenclature]] officially approved the binominal ''Plasmodium falciparum''.<ref name=chwatt>{{cite journal|last1=Bruce-Chwatt|first1=L.J.|title=Falciparum nomenclature|journal=Parasitology Today|date=1987|volume=3|issue=8|pages=252|doi=10.1016/0169-4758(87)90153-0|pmid=15462972}}</ref> The valid genus ''Plasmodium'' was created by two Italian physicians [[Ettore Marchiafava]] and [[Angelo Celli]] in 1885. The Greek word ''plasma'' means "mould" or "form"; ''oeidēs'' means "to see" or "to know." The species name was introduced by an American physician [[William Henry Welch]] in 1897.<ref>{{cite journal|last1=Christophers|first1=R|last2=Sinton|first2=JA|title=Correct Name of Malignant Tertian Parasite|journal=British Medical Journal|date=1938|volume=2|issue=4065|pages=1130–1134|pmid=20781927|pmc=2211005|doi=10.1136/bmj.2.4065.1130}}</ref> It is derived from the Latin ''falx'', meaning "sickle" and ''parum'' meaning "like or equal to another".<ref name=chwatt/>

=== Origin and evolution ===
''P. falciparum'' is now generally accepted to have evolved from ''[[Laverania]]'' (a subgenus of ''Plasmodium'' found in apes) species present in gorillas in Western Africa.<ref>{{cite journal|last1=Liu|first1=W|last2=Li|first2=Y|last3=Learn|first3=GH|last4=Rudicell|first4=RS|last5=Robertson|first5=JD|last6=Keele|first6=BF|last7=Ndjango|first7=JB|last8=Sanz|first8=CM|last9=Morgan|first9=DB|last10=Locatelli|first10=S|last11=Gonder|first11=MK|last12=Kranzusch|first12=PJ|last13=Walsh|first13=PD|last14=Delaporte|first14=E|last15=Mpoudi-Ngole|first15=E|last16=Georgiev|first16=AV|last17=Muller|first17=MN|last18=Shaw|first18=GM|last19=Peeters|first19=M|last20=Sharp|first20=PM|last21=Rayner|first21=JC|last22=Hahn|first22=BH|title=Origin of the human malaria parasite'' Plasmodium falciparum'' in gorillas|journal=Nature|date= 2010|volume=467|issue=7314|pages=420–5|doi=10.1038/nature09442|pmid=20864995|pmc=2997044|display-authors=8|bibcode=2010Natur.467..420L}}</ref><ref>{{cite journal|last1=Holmes|first1=Edward C.|title=Malaria: The gorilla connection|journal=Nature|date=2010|volume=467|issue=7314|pages=404–405|doi=10.1038/467404a|pmid=20864986|bibcode=2010Natur.467..404H|s2cid=205058952|doi-access=free}}</ref> Genetic diversity indicates that the human protozoan emerged around 10,000 years ago.<ref name=loy/><ref name=":2" /> The closest relative of ''P. falciparum'' is ''P. praefalciparum'', a parasite of [[gorilla]]s, as supported by [[mitochondrial DNA|mitochondrial]], [[apicoplast]]ic and [[nuclear DNA]] sequences.<ref name="Liu et al. 2010">{{cite journal |last1=Liu |first1=Weimin |last2=Li |first2=Yingying |last3=Learn |first3=Gerald H. |last4=Rudicell |first4=Rebecca S. |last5=Robertson |first5=Joel D. |last6=Keele |first6=Brandon F. |last7=Ndjango |first7=Jean-Bosco N. |last8=Sanz |first8=Crickette M. |last9=Morgan |first9=David B. |last10=Locatelli |first10=Sabrina |last11=Gonder |first11=Mary K. |last12=Kranzusch |first12=Philip J. |last13=Walsh |first13=Peter D. |last14=Delaporte |first14=Eric |last15=Mpoudi-Ngole |first15=Eitel |last16=Georgiev |first16=Alexander V. |last17=Muller |first17=Martin N. |last18=Shaw |first18=George M. |last19=Peeters |first19=Martine |last20=Sharp |first20=Paul M. |last21=Rayner |first21=Julian C. |last22=Hahn |first22=Beatrice H. |title=Origin of the human malaria parasite ''Plasmodium falciparum'' in gorillas |journal=Nature |date=September 2010 |volume=467 |issue=7314 |pages=420–425 |doi=10.1038/nature09442 |bibcode = 2010Natur.467..420L| pmid=20864995
| pmc=2997044}}</ref><ref name="Duval et al. 2010">{{cite journal |last1=Duval |first1=Linda |last2=Fourment |first2=Mathieu |last3=Nerrienet |first3=Eric |last4=Rousset |first4=Dominique |last5=Sadeuh |first5=Serge A. |last6=Goodman |first6=Steven M. |last7=Andriaholinirina |first7=Nicole V. |last8=Randrianarivelojosia |first8=Milijaona |last9=Paul |first9=Richard E. |last10=Robert |first10=Vincent |last11=Ayala |first11=Francisco J. |last12=Ariey |first12=Frédéric |title=African apes as reservoirs of ''Plasmodium falciparum'' and the origin and diversification of the Laverania subgenus |journal=Proceedings of the National Academy of Sciences |date=8 June 2010 |volume=107 |issue=23 |pages=10561–10566 |doi=10.1073/pnas.1005435107 |pmid=20498054 |pmc=2890828 |bibcode=2010PNAS..10710561D |doi-access = free
}}</ref><ref name="Rayner et al. 2010">{{cite journal |last1=Rayner |first1=Julian C. |last2=Liu |first2=Weimin |last3=Peeters |first3=Martine |last4=Sharp |first4=Paul M. |last5=Hahn |first5=Beatrice H. |title=A plethora of Plasmodium species in wild apes: a source of human infection? |journal=Trends in Parasitology |date=May 2011 |volume=27 |issue=5 |pages=222–229 |doi=10.1016/J.Pt.2011.01.006 |pmid=21354860 |pmc=3087880}}</ref> These two species are closely related to the [[Common chimpanzee|chimpanzee]] parasite ''P. reichenowi'', which was previously thought to be the closest relative of ''P. falciparum''. ''P. falciparum'' was also once thought to originate from a parasite of birds.<ref name="Rathore et al. 2001">{{cite journal |last1=Rathore |first1=Dharmendar |last2=Wahl |first2=Allison M |last3=Sullivan |first3=Margery |last4=McCutchan |first4=Thomas F |title=A phylogenetic comparison of gene trees constructed from plastid, mitochondrial and genomic DNA of Plasmodium species |journal=Molecular and Biochemical Parasitology |date=April 2001 |volume=114 |issue=1 |pages=89–94 |doi=10.1016/S0166-6851(01)00241-9}}</ref>

Levels of genetic [[Polymorphism (biology)|polymorphism]] are extremely low within the ''P. falciparum'' genome compared to that of closely related, ape infecting species of ''Plasmodium'' (including ''P. praefalciparum'').<ref name="Hartl 2004">{{Cite journal| volume = 2| issue = 1| pages = 15–22| last = Hartl| first = DH| title = The origin of malaria: mixed messages from genetic diversity| journal = Nature Reviews Microbiology| date = January 2004
| pmid=15035005| doi = 10.1038/nrmicro795| s2cid = 11020105}}</ref><ref name="Liu et al. 2010" /> This suggests that the origin of ''P. falciparum'' in humans is recent, as a single ''P. praefalciparum'' strain became capable of infecting humans.<ref name="Liu et al. 2010" /> The genetic information of ''P. falciparum'' has signaled a recent expansion that coincides with the agricultural revolution. The development of extensive agriculture likely increased mosquito population densities by giving rise to more breeding sites, which may have triggered the evolution and expansion of ''P. falciparum''.<ref>{{cite journal | last1 = Hume | first1 = J.C. | last2 = Lyons | first2 = E.J. | last3 = Day | first3 = K.P. | year = 2003 | title = Human migration, mosquitoes and the evolution of ''Plasmodium falciparum'' | journal = Trends Parasitol | volume = 19 | issue = 3| pages = 144–9 | doi=10.1016/s1471-4922(03)00008-4| pmid = 12643998 }}</ref>