Editing Malaria (section)

==Signs and symptoms==
[[File:Symptoms of Malaria.png|thumb|upright=1.15|Main symptoms of malaria<ref name="Fairhurst-2015"/>]]

Adults with malaria tend to experience chills and fever—classically in periodic [[Paroxysmal attack|intense bouts]] lasting around six hours, followed by a period of sweating and fever relief—as well as headache, fatigue, abdominal discomfort, and [[myalgia|muscle pain]].<ref name="Despommier-2019">{{cite book |url=https://parasiteswithoutborders.com/wp-content/uploads/2020/02/PD7thEditionLowResVersion5-11-2019.pdf |title=Parasitic Diseases |vauthors=Despommier DD, Griffin DO, Gwadz RW, Hotez PJ, Knirsch CA |date=2019 |publisher=Parasites Without Borders |edition=7 |location=New York |pages=110–115 |chapter=9. The Malarias |access-date=November 24, 2021 |archive-date=November 24, 2021 |archive-url=https://web.archive.org/web/20211124214329/https://parasiteswithoutborders.com/wp-content/uploads/2020/02/PD7thEditionLowResVersion5-11-2019.pdf |url-status=live }}</ref> Children tend to have more general symptoms: fever, cough, vomiting, and diarrhea.<ref name="Despommier-2019"/>

Initial manifestations of the disease—common to infection with all malaria parasite species—are similar to [[flu|flu-like symptoms]],<ref name="Bartoloni-2012"/> and can resemble other conditions such as [[sepsis]], [[gastroenteritis]], and [[viral disease]]s.<ref name="Nadjm-2012"/> The presentation may include [[headache]], [[fever]], [[shivering]], [[arthralgia|joint pain]], [[vomiting]], [[hemolytic anemia]], [[jaundice]], [[hemoglobinuria|hemoglobin in the urine]], [[Retinopathy|retinal damage]], and [[convulsion]]s.<ref name="Beare-2006"/>

The classic symptom of malaria is [[Paroxysmal attacks|paroxysm]]—a cyclical occurrence of sudden coldness followed by shivering and then fever and sweating, occurring every two days ([[Fever#Types|tertian fever]]) in ''P.&nbsp;vivax'' and ''P.&nbsp;ovale'' infections, and every three days ([[Fever#Types|quartan fever]]) for ''P.&nbsp;malariae''. ''P.&nbsp;falciparum'' infection can cause recurrent fever every 36–48 hours, or a less pronounced and almost continuous fever.<ref name="Ferri-2009"/>

Symptoms typically begin 10–15 days after the initial mosquito bite, but can occur as late as several months after infection with some ''P. vivax'' strains.<ref name="Despommier-2019"/> Travellers taking preventative malaria medications may develop symptoms once they stop taking the drugs.<ref name="Despommier-2019"/>

Severe malaria is usually caused by ''P.&nbsp;falciparum'' (often referred to as falciparum malaria). Symptoms of falciparum malaria arise 9–30 days after infection.<ref name="Bartoloni-2012"/> Individuals with cerebral malaria frequently exhibit [[neurological disorder|neurological]] symptoms, including [[abnormal posturing]], [[nystagmus]], [[conjugate gaze palsy]] (failure of the eyes to turn together in the same direction), [[opisthotonus]], [[seizure]]s, or [[coma]].<ref name="Bartoloni-2012"/>

===Diagnosis based on skin odor profiles===

Humans emanate a large range of smells. Studies have been conducted on how to detect human malaria infections through volatile compounds from the skin. Volatile biomarkers may be a reliable source for the detection of infection, including those asymptomatic. Using skin body odor profiles can be efficient in diagnosing global populations, and the screening and monitoring of infection to officially eradicate malaria. Research findings have predominantly relied on chemical explanations to explain the differences in attractiveness among humans based on distinct odor profiles. The existence of volatile compounds, like fatty acids, and lactic acid is an essential reason on why some individuals are more appealing to mosquitos than others.

====Volatile compounds====

Kanika Khanna, a postdoctoral scholar at the University of California, Berkeley studying the structural basis of membrane manipulation and cell-cell fusion by bacterial pathogens, discusses studies that determine how odor profiles can be used to diagnose the disease. Within the study, samples of volatile compounds from around 400 children within schools in Western Kenya were collected to identify asymptomatic infections. These biomarkers have been established as a non-invasive way to detect malarial infections. In addition, these volatile compounds were heavily detected by mosquito antennae as an attractant, making the children more vulnerable to the bite of the mosquitos.<ref>{{cite news | vauthors = Khanna K |title=Microbial Origins of Body Odor |url=https://asm.org/articles/2021/december/microbial-origins-of-body-odor |publisher=American Society for Microbiology |date=30 December 2021 }}</ref>

====Fatty acids====

Fatty acids have been identified as an attractive compound for mosquitoes, they are typically found in volatile emissions from the skin. These fatty acids that produce body odor profiles originate from the metabolism of glycerol, lactic acid, amino acids, and lipids through the action of bacteria found within the skin. They create a "chemical signature" for the mosquitoes to locate a potential host, humans in particular.<ref name="Dormont-2021">{{cite journal | vauthors = Dormont L, Mulatier M, Carrasco D, Cohuet A | title = Mosquito Attractants | journal = Journal of Chemical Ecology | volume = 47 | issue = 4–5 | pages = 351–393 | date = May 2021 | pmid = 33725235 | doi = 10.1007/s10886-021-01261-2 | bibcode = 2021JCEco..47..351D }}</ref>

====Lactic acid====

Lactic acid, a naturally produced levorotatory isomer, has been titled an attractant of mosquitoes for a long time.{{quantify|date=March 2025}} Lactic acid is predominantly produced by eccrine-sweat glands, creating a large amount of sweat on the surface of the skin. Due to the high levels of lactic acid released from the human body, it has been hypothesized to represent a specific human host-recognition cue for anthropophilic (attracted to humans) mosquitoes.{{cn|date=March 2025}}

====Pungent foot odor====

Most studies use human odors as stimuli to attract host seeking mosquitoes and have reported a strong and significant attractive effect. The studies have found human odor samples very effective in attracting mosquitoes. Foot odors have been demonstrated to have the highest attractiveness to anthropophilic mosquitoes. Some of these studies have included traps that had been baited with nylon socks previously worn by human participants and were deemed efficient in catching adult mosquitos. Foot odors have high numbers of volatile compounds, which in turn elicit an olfactory response from mosquitoes.<ref name="Dormont-2021"/>

===Complications===
Malaria has several serious [[Complication (medicine)|complications]], including the development of [[respiratory distress]], which occurs in up to 25% of adults and 40% of children with severe ''P.&nbsp;falciparum'' malaria. Possible causes include respiratory compensation of [[metabolic acidosis]], noncardiogenic [[pulmonary oedema]], concomitant [[pneumonia]], and severe [[anaemia]]. Although rare in young children with severe malaria, [[acute respiratory distress syndrome]] occurs in 5–25% of adults and up to 29% of pregnant women.<ref name="Taylor-2012"/> [[Coinfection]] of [[HIV]] with malaria increases mortality.<ref name="Korenromp-2005"/> [[Kidney failure]] is a feature of [[blackwater fever]], where haemoglobin from [[lysis|lysed]] red blood cells leaks into the urine.<ref name="Bartoloni-2012"/>

Infection with ''P.&nbsp;falciparum'' may result in cerebral malaria, a form of severe malaria that involves [[encephalopathy]]. It is associated with retinal whitening, which may be a useful clinical sign in distinguishing malaria from other causes of fever.<ref name="Beare-2011"/> An [[Splenomegaly|enlarged spleen]], [[hepatomegaly|enlarged liver]] or [[hepatosplenomegaly|both of these]], severe headache, [[hypoglycemia|low blood sugar]], and [[hemoglobinuria|haemoglobin in the urine]] with [[kidney failure]] may occur.<ref name="Bartoloni-2012"/> Complications may include spontaneous bleeding, [[coagulopathy]], and [[circulatory shock|shock]].<ref>Davidson's Principles and Practice of Medicine/21st/351</ref> 

Cerebral malaria can bring about death within forty-eight hours of the first symptoms of the infection being evident. 

[[Pregnancy-associated malaria|Malaria during pregnancy]] can cause [[stillbirth]]s, [[infant mortality]], [[miscarriage]], and [[low birth weight]],<ref name="Hartman-2010"/> particularly in ''P.&nbsp;falciparum'' infection, but also with ''P.&nbsp;vivax''.<ref name="Rijken-2012"/>