Editing Plasmodium (section)

==Distribution==
''Plasmodium'' species are distributed globally. All ''Plasmodium'' species are parasitic and must pass between a vertebrate host and an insect host to complete their life cycles. Different species of ''Plasmodium'' display different host ranges, with some species restricted to a single vertebrate and insect host, while other species can infect several species of vertebrates and/or insects.

=== Vertebrates ===
[[File:Relative incidence of Plasmodium (malaria) species by country of origin for imported cases to non-endemic countries.png|thumb|Relative incidence of Plasmodium species by country of origin for imported cases to non-endemic countries<ref name="Tatem2017">{{Cite journal |author1=Tatem AJ |author2=Jia P |author3=Ordanovich D |author4=Falkner M |author5=Huang Z |author6=Howes R |author7=Hay S |author8=Gething, P W |author9=Smith, D L |display-authors=etal |title=The geography of imported malaria to non-endemic countries: a meta-analysis of nationally reported statistics |journal=Lancet Infect Dis |year=2017 |volume=17 |issue=1 |pages=98–107 |pmid=27777030 |doi=10.1016/S1473-3099(16)30326-7 |pmc=5392593 }}</ref>]]

''Plasmodium'' parasites have been described in a broad array of vertebrate hosts including reptiles, birds, and mammals.<ref name=Manguin/> While many species can infect more than one vertebrate host, they are generally specific to one of these [[Class (biology)|classes]] (such as birds).<ref name=Manguin>{{cite book|title=Biodiversity of Malaria in the world |date=2008 |author1=Manguin, S. |author2=Carnevale, P. |author3=Mouchet, J. |author4=Coosemans, M. |author5=Julvez, J. |author6=Richard-Lenoble, D. |author7=Sircoulon, J. |publisher=John Libbey |isbn=978-2-7420-0616-8 |pages=13–15 |url=https://books.google.com/books?id=Sk0JBAAAQBAJ&q=malaria+reptile&pg=PA13 |access-date=15 March 2018}}</ref>

Humans are primarily infected by [[List of Plasmodium species infecting primates#Species infecting humans|five species]] of ''Plasmodium'', with the overwhelming majority of severe disease and death caused by ''[[Plasmodium falciparum]]''.<ref name=Scully>{{cite journal |doi=10.1016/j.mib.2017.10.006|pmid=29096194|pmc=5733638 |title=Molecular interactions governing host-specificity of blood stage malaria parasites|journal=Current Opinion in Microbiology |volume=40|pages=21–31 |year=2017 |last1=Scully |first1=Erik J. |last2=Kanjee|first2=Usheer|last3=Duraisingh|first3=Manoj T.}}</ref> Some species that infect humans can also infect other primates, and zoonoses of certain species (e.g. ''[[Plasmodium knowlesi|P. knowlesi]]'') from other primates to humans are common.<ref name=Scully/> Non-human primates also contain a [[List of Plasmodium species infecting primates|variety of ''Plasmodium'' species]] that do not generally infect humans. Some of these can cause severe disease in primates, while others can remain in the host for prolonged periods without causing disease.<ref name=Nunn>{{cite book |author1=Nunn, C. |author2=Altizer, S. |date=2006 |title=Infectious Diseases in Primates: Behavior, Ecology and Evolution |url=https://books.google.com/books?id=1s0TDAAAQBAJ&q=plasmodium&pg=PA254 |edition=1st |publisher=Oxford University Press |pages=253–254 |isbn=978-0198565840 |access-date=16 March 2018}}</ref> Many other mammals also carry [[Vinckeia|''Plasmodium'' species]], such as a variety of [[rodents]], [[ungulates]], and [[bat]]s. Again, some species of ''Plasmodium'' can cause severe disease in some of these hosts, while many appear not to.<ref>{{cite journal|title=The rediscovery of malaria parasites of ungulates |journal=Parasitology |volume=143 |issue=12 |date=2016 |pages=1501–1508 |vauthors=Templeton TJ, Martinsen E, Kaewthamasorn M, Kaneko O |doi=10.1017/S0031182016001141|pmid=27444556 |s2cid=22397021 }}</ref>

[[List of Plasmodium species infecting birds|Over 150 species of ''Plasmodium'']] infect a broad variety of birds. In general each species of ''Plasmodium'' infects one to a few species of birds.<ref name=Valkiunas2>{{cite book|title=Avian Malaria Parasites and Other Haemosporidia |author=Valkiunas, Gediminas |publisher=CRC Press |isbn=9780415300971 |date=2004 |chapter=Specificity and general Principles of Species Identification |pages=67–81}}</ref> ''Plasmodium'' parasites that infect birds tend to persist in a given host for years or for the life time of the host, although in some cases ''Plasmodium'' infections can result in severe illness and rapid death.<ref name=Valkiunas>{{cite book|title=Avian Malaria Parasites and Other Haemosporidia |author=Valkiunas, Gediminas |publisher=CRC Press |isbn=9780415300971 |date=2004 |chapter=General Section - Life Cycle and Morphology of Plasmodiidae Species |pages=27–35}}</ref><ref name=Valkiunas3>{{cite book|title=Avian Malaria Parasites and Other Haemosporidia |author=Valkiunas, Gediminas  |publisher=CRC Press |isbn=9780415300971 |date=2004 |chapter=Pathogenicity |pages=83–111}}</ref> Unlike with ''Plasmodium'' species infecting mammals, those infecting birds are distributed across the globe.<ref name=Valkiunas2/>

[[List of Plasmodium species infecting reptiles|Species from several subgenera]] of ''Plasmodium'' infect diverse [[reptiles]]. ''Plasmodium'' parasites have been described in most lizard [[Family (biology)|families]] and, like avian parasites, are spread worldwide.<ref name=Zug>{{cite book|title=Herpetology: An Introductory Biology of Amphibians and Reptiles |editor1=Zug, G. R. |editor2=Vitt, L. J. |isbn=978-0127826202 |publisher=Academic Press |date=2012 |url=https://books.google.com/books?id=nqgpcru2sfwC&q=malaria+reptile&pg=PA152 |access-date=16 March 2018 |page=152}}</ref> Again, parasites can result either in severe disease or be apparently asymptomatic depending on the parasite and the host.<ref name=Zug/>

A number of [[Antimalarial medication|drugs]] have been developed over the years to control ''Plasmodium'' infection in vertebrate hosts, particularly in humans. [[Quinine]] was used as a frontline antimalarial from the 17th century until widespread [[antimicrobial resistance|resistance]] emerged in the early 20th century.<ref name="Blasco2018">{{cite journal |last1=Blasco |first1=Benjamin |last2=Leroy |first2=Didier |last3=Fidock |first3=David A. |author-link3=David A. Fidock |year=2017 |title=Antimalarial drug resistance: Linking Plasmodium falciparum parasite biology to the clinic |journal=Nature Medicine |volume=23 |issue=8 |pages=917–928 |doi=10.1038/nm.4381 |pmc=5747363 |pmid=28777791}}</ref> Resistance to quinine spurred the development of a broad array of antimalarial medications through the 20th century including [[chloroquine]], [[proguanil]], [[atovaquone]], [[sulfadoxine/pyrimethamine]], [[mefloquine]], and [[artemisinin]].<ref name=Blasco2018/> In all cases, parasites resistant to a given drug have emerged within a few decades of the drugs deployment.<ref name=Blasco2018/> To combat this, antimalarial drugs are frequently used in combination, with [[artemisinin combination therapy|artemisinin combination therapies]] currently the gold standard for treatment.<ref name=Cowman2016>{{cite journal |doi=10.1016/j.cell.2016.07.055 |pmid=27768886|title=Malaria: Biology and Disease |journal=Cell |volume=167|issue=3 |pages=610–624|year=2016|last1=Cowman |first1=Alan F|last2=Healer|first2=Julie |last3=Marapana |first3=Danushka|last4=Marsh |first4=Kevin|doi-access=free}}</ref> In general, antimalarial drugs target the life stages of ''Plasmodium'' parasites that reside within vertebrate red blood cells, as these are the stages that tend to cause disease.<ref name=Haldar2018>{{cite journal|doi=10.1038/nrmicro.2017.161 |pmid=29355852|pmc=6371404|title=Drug resistance in Plasmodium |journal=Nature Reviews Microbiology|volume=16|issue=3 |pages=156–170 |year=2018|last1=Haldar |first1=Kasturi |last2=Bhattacharjee|first2=Souvik|last3=Safeukui|first3=Innocent}}</ref> However, drugs targeting other stages of the parasite life cycle are under development in order to prevent infection in travelers and to prevent transmission of sexual stages to insect hosts.<ref>{{cite journal|doi=10.1002/med.21486 |pmid=29372568 |title=Multistage inhibitors of the malaria parasite: Emerging hope for chemoprotection and malaria eradication |journal=Medicinal Research Reviews |volume=38 |issue=5 |pages=1511–1535 |year=2018 |last1=Poonam |last2=Gupta |first2=Yash |last3=Gupta |first3=Nikesh |last4=Singh |first4=Snigdha |last5=Wu |first5=Lidong |last6=Chhikara |first6=Bhupender Singh |last7=Rawat |first7=Manmeet |last8=Rathi |first8=Brijesh |s2cid=25711437 }}</ref>

<gallery widths="200px" heights="160px">
File:Saving_Lives_with_SMS_for_Life.jpg|A clinic for treating human malaria in Tanzania
File:Anolis carolinensis.jpg|Over 3000 species of lizard, including the [[Carolina anole]] (''Anolis carolinensis''), carry some 90 kinds of malaria.
</gallery>

=== Insects ===
[[File:Anopheles stephensi.jpeg|thumb|The mosquito ''[[Anopheles stephensi]]'' is among the blood-feeding insects that can be infected by a species of ''Plasmodium''.]]

In addition to a vertebrate host, all ''Plasmodium'' species also infect a [[hematophagy|bloodsucking]] insect host, generally a mosquito (although some reptile-infecting parasites are transmitted by [[sandfly|sandflies]]). Mosquitoes of the genera ''[[Culex]]'', ''[[Anopheles]]'', ''[[Culiseta]]'', ''[[Mansonia (fly)|Mansonia]]'' and ''[[Aedes]]'' act as insect hosts for various ''Plasmodium'' species. The best studied of these are the ''Anopheles'' mosquitoes which host the ''Plasmodium'' parasites of human malaria, as well as ''Culex'' mosquitoes which host the ''Plasmodium'' species that cause malaria in birds. Only female mosquitoes are infected with ''Plasmodium'', since only they feed on the blood of vertebrate hosts.<ref>{{Cite journal |last1=Crompton |first1=Peter D. |last2=Moebius |first2=Jacqueline |last3=Portugal |first3=Silvia |last4=Waisberg |first4=Michael |last5=Hart |first5=Geoffrey |last6=Garver |first6=Lindsey S. |last7=Miller |first7=Louis H. |last8=Barillas-Mury |first8=Carolina |last9=Pierce |first9=Susan K. |date=2014 |title=Malaria Immunity in Man and Mosquito: Insights into Unsolved Mysteries of a Deadly Infectious Disease |journal=Annual Review of Immunology |volume=32 |issue=1 |pages=157–187 |doi=10.1146/annurev-immunol-032713-120220 |pmid=24655294 |pmc=4075043}}</ref> Different species affect their insect hosts differently. Sometimes, insects infected with ''Plasmodium'' have reduced lifespan and reduced ability to produce offspring.<ref name=Busula>{{cite journal |doi=10.1016/j.pt.2017.08.010 |pmid=28942108 |title=Mechanisms of Plasmodium -Enhanced Attraction of Mosquito Vectors |journal=Trends in Parasitology |volume=33 |issue=12 |pages=961–973 |year=2017 |last1=Busula |first1=Annette O. |last2=Verhulst |first2=Niels O. |last3=Bousema |first3=Teun |last4=Takken |first4=Willem |last5=De Boer |first5=Jetske G.}}</ref> Further, some species of ''Plasmodium'' appear to cause insects to prefer to bite infected vertebrate hosts over non-infected hosts.<ref name=Busula/><ref>{{cite journal |doi=10.1016/j.cois.2017.02.002 |pmid=28602239 |title=Effects of malaria infection on mosquito olfaction and behavior: Extrapolating data to the field |journal=Current Opinion in Insect Science |volume=20 |pages=7–12 |year=2017 |last1=Stanczyk |first1=Nina M. |last2=Mescher |first2=Mark C. |last3=De Moraes |first3=Consuelo M.|doi-access=free }}</ref><ref>{{cite journal |doi=10.1101/cshperspect.a025593 |pmid=28389513 |title=Anopheline Reproductive Biology: Impacts on Vectorial Capacity and Potential Avenues for Malaria Control |journal=Cold Spring Harbor Perspectives in Medicine |volume=7 |issue=12 |pages=a025593 |year=2017 |last1=Mitchell |first1=Sara N. |last2=Catteruccia |first2=Flaminia|pmc=5710097 |author-link2=Flaminia Catteruccia}}</ref>