Editing Malaria (section)

===Climate change===
{{Further|Climate change and infectious diseases#Malaria}}

[[Climate change]] is likely to affect malaria transmission, but the degree of effect and the areas affected is uncertain.<ref name="Climate Change and Human Health—Risk and Responses">{{cite web|title=Climate Change And Infectious Diseases|url=https://www.who.int/globalchange/climate/en/chapter6.pdf|url-status=live|archive-url=https://web.archive.org/web/20160304063626/http://www.who.int/globalchange/climate/en/chapter6.pdf|archive-date=2016-03-04|work=Climate Change and Human Health—Risk and Responses|publisher=World Health Organization}}</ref> Greater rainfall in certain areas of India, and following an [[El Niño]] event is associated with increased mosquito numbers.<ref>{{cite web|title=Climate change and human health—risks and responses. Summary|url=https://www.who.int/globalchange/climate/summary/en/index5.html|archive-url=https://web.archive.org/web/20031225023503/http://www.who.int/globalchange/climate/summary/en/index5.html|url-status=dead|archive-date=December 25, 2003|access-date=29 October 2018|publisher=World Health Organization}}</ref>

Since 1900 there has been substantial change in temperature and rainfall over Africa.<ref>{{Cite journal|vauthors=Hulme M, Doherty R, Ngara T, New M, Lister D|date=August 2001|title=African climate change: 1900-2100.|url=https://www.int-res.com/articles/cr/17/c017p145.pdf|journal=Climate Research|volume=17|issue=2|pages=145–68|doi=10.3354/cr017145|bibcode=2001ClRes..17..145H|doi-access=free|access-date=2020-09-08|archive-date=2021-06-30|archive-url=https://web.archive.org/web/20210630114729/https://www.int-res.com/articles/cr/17/c017p145.pdf|url-status=live}}</ref> However, factors that contribute to how rainfall results in water for mosquito breeding are complex, incorporating the extent to which it is absorbed into soil and vegetation for example, or rates of runoff and evaporation.<ref name="Smith-2020">{{cite journal | vauthors = Smith MW, Willis T, Alfieri L, James WH, Trigg MA, Yamazaki D, Hardy AJ, Bisselink B, De Roo A, Macklin MG, Thomas CJ |display-authors=6 | title = Incorporating hydrology into climate suitability models changes projections of malaria transmission in Africa | journal = Nature Communications | volume = 11 | issue = 1 | pages = 4353 | date = August 2020 | pmid = 32859908 | pmc = 7455692 | doi = 10.1038/s41467-020-18239-5 | bibcode = 2020NatCo..11.4353S }}</ref> Recent research has provided a more in-depth picture of conditions across Africa, combining a malaria climatic suitability model with a continental-scale model representing real-world hydrological processes.<ref name="Smith-2020" />

====Changes in geographic distribution====

Climate change has led to shifts in malaria-endemic regions, with the disease expanding into higher altitudes and previously malaria-free areas.<ref name=Caminade14>{{cite journal |vauthors=Caminade C, Kovats S, Rocklov J, Tompkins AM, Morse AP, Colón-González FJ, Stenlund H, Martens P, Lloyd SJ |display-authors=6 |title=Impact of climate change on global malaria distribution |journal=Proceedings of the National Academy of Sciences USA |volume=111 |issue=9 |pages=3286–91 |date=March 2014 |pmid=24596427 |pmc=3948226 |doi=10.1073/pnas.1302089111 |doi-access=free |bibcode=2014PNAS..111.3286C }}</ref>
Rising temperatures allow mosquitoes to survive in regions that were once too cold for them, including highland areas in Africa, South America, and parts of Asia.<ref name=Caminade14/>
A study analyzing malaria cases in Ethiopian and Colombian highlands found a strong correlation between increased temperatures and malaria incidence, demonstrating that climate change has made previously inhospitable areas suitable for transmission.<ref name=Siraj14>{{cite journal |vauthors=Siraj AS, Santos-Vega M, Bouma MJ, Yadeta D, Ruiz Carrascal D, Pascual M |title=Altitudinal changes in malaria incidence in highlands of Ethiopia and Colombia |journal=Science |volume=343 |issue=6175 |pages=1154–8 |date=March 2014 |pmid=24604201 |doi=10.1126/science.1244325 |bibcode=2014Sci...343.1154S }}</ref>

====Increased transmission season====

Malaria transmission is highly sensitive to temperature and rainfall patterns.<ref name=Siraj14/> Climate change has led to longer transmission seasons in tropical regions, where mosquitoes can breed year-round due to prolonged periods of high humidity and warm temperatures.<ref name=Sewe21>{{cite journal |vauthors=Colón-González FJ, Sewe MO, Tompkins AM, Sjödin H, Casallas A, Rocklöv J, Caminade C, Lowe R |title=Projecting the risk of mosquito-borne diseases in a warmer and more populated world: a multi-model, multi-scenario intercomparison modelling study |journal=Lancet Planet Health |volume=5 |issue=7 |pages=e404–14 |date=July 2021 |pmid=34245711 |pmc=8280459 |doi=10.1016/S2542-5196(21)00132-7 }}</ref> Research suggests that in parts of sub-Saharan Africa, the malaria transmission season has lengthened by several months, particularly in regions where warming has pushed temperatures into the optimal range for Plasmodium falciparum development.<ref name=Sewe21/> In regions such as West Africa and parts of India, increasing temperatures and prolonged rainy seasons have contributed to a rise in malaria cases.<ref name=Sewe21/> Some studies predict that by 2050, many malaria-endemic areas will experience a 20–30% increase in transmission duration due to warming trends.<ref name=Caminade14/>

====Effects of extreme weather events====

Extreme weather events, such as heavy rainfall, flooding, and droughts, are increasing in frequency and intensity due to climate change, creating favorable conditions for malaria outbreaks.<ref name=Bouma96>{{cite journal |vauthors=Bouma MJ, van der Kaay HJ |title=The El Niño Southern Oscillation and the historic malaria epidemics on the Indian subcontinent and Sri Lanka: an early warning system for future epidemics? |journal=Tropical Medicine & International Health |volume=1 |issue=1 |pages=86–96 |date=February 1996 |pmid=8673827 |doi=10.1046/j.1365-3156.1996.d01-7.x }}</ref> Flooding provides ideal breeding grounds for mosquitoes by forming stagnant water pools, while droughts can also exacerbate malaria by forcing human populations to store water in open containers, which serve as mosquito habitats.<ref name=Bouma96/> This effect has been observed in parts of sub-Saharan Africa and South Asia, where prolonged drought periods were followed by spikes in malaria cases.<ref name=Bouma96/> A review of malaria outbreaks linked to climate variability found that El Niño events, which increase rainfall and temperatures in malaria-endemic regions, have been associated with significant surges in cases.<ref>{{cite journal |vauthors=Hay SI, Shanks GD, Stern DI, Snow RW, Randolph SE, Rogers DJ |title=Climate variability and malaria epidemics in the highlands of East Africa |journal=Trends in Parasitology |volume=21 |issue=2 |pages=52–53 |date=February 2005 |pmid=15664524 |pmc=3173848 |doi=10.1016/j.pt.2004.11.007 }}</ref>

====Resistance and adaptation of vectors====

Higher temperatures accelerate the development of ''Plasmodium'' parasites within mosquitoes, potentially leading to increased transmission efficiency.<ref name=Shapiro17>{{cite journal |vauthors=Shapiro LL, Whitehead SA, Thomas MB |title=Quantifying the effects of temperature on mosquito and parasite traits that determine the transmission potential of human malaria |journal=PLOS Biology |volume=15 |issue=10 |pages=e2003489 |date=October 2017 |pmid=29036170 |pmc=5658182 |doi=10.1371/journal.pbio.2003489 |doi-access=free}}</ref> Additionally, rising temperatures and changing environmental conditions have been linked to the spread of insecticide resistance in mosquito populations, complicating malaria control efforts.<ref name=Shapiro17/> A global survey found that Anopheles mosquitoes in Africa, Asia, and South America have developed increased resistance to commonly used insecticides such as pyrethroids.<ref>{{cite journal |vauthors=Suh PF, Elanga-Ndille E, Tchouakui M, Sandeu MM, Tagne D, Wondji C, Ndo C |title=Impact of insecticide resistance on malaria vector competence: a literature review |journal=Malaria Journal |volume=22 |issue=1 |pages=19 |date=January 2023 |pmid=36650503 |pmc=9847052 |doi=10.1186/s12936-023-04444-2 |doi-access=free}}</ref>