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133-650: In 1963 a predecessor organization was established, the Organisation des Etats Riverians du Fleuve Sénégal (or the Senegal River Riparian States Organization), with the four border countries—Guinea, Mali, Mauritania, and Senegal—to manage the Sénégal River drainage basin and the river itself. This organization dissolved when Guinea withdrew due to political tensions and the three remaining countries subsequently created

266-447: A diploid cell called a zygote . The zygote then develops into an ookinete . The ookinete is a motile cell, capable of invading other organs of the mosquito. It traverses the peritrophic membrane of the mosquito midgut and crosses the midgut epithelium. Once through the epithelium, the ookinete enters the basal lamina , and settles to an immotile oocyst . For several days, the oocyst undergoes 10 to 11 rounds of cell division to create

399-525: A syncytial cell ( sporoblast ) containing thousands of nuclei. Meiosis takes place inside the sporoblast to produce over 3,000 haploid daughter cells called sporozoites on the surface of the mother cell. Immature sporozoites break through the oocyst wall into the haemolymph . They migrate to the mosquito salivary glands where they undergo further development and become infective to humans. Effects of plant secondary metabolites on P. falciparum Mosquitoes are known to forage on plant nectar for sugar meal,

532-669: A Greek word for pollution. 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 anopheline mosquito (in his case Anopheles claviger ). Ross, Manson and Grassi were nominated for

665-596: 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

798-575: A blood meal from a previously Plasmodium infected person or animal. Parasites are then typically introduced by the bite of an infected Anopheles mosquito. Some of these inoculated parasites, called " sporozoites ", probably remain in the skin, but others travel in the bloodstream to the liver , where they invade hepatocytes . They grow and divide in the liver for 2–10 days, with each infected hepatocyte eventually harboring up to 40,000 parasites. The infected hepatocytes break down, releasing these invasive Plasmodium cells, called " merozoites ", into

931-462: A child under five died of malaria in 2021, and "many of these deaths are preventable and treatable". Malaria is commonly associated with poverty and has a significant negative effect on economic development. In Africa, it is estimated to result in losses of US$ 12 billion a year due to increased healthcare costs, lost ability to work, and adverse effects on tourism. The term malaria originates from Medieval Italian : mala aria 'bad air',

1064-634: A class of insecticides with low toxicity . They are most effective when used from dusk to dawn. It is recommended to hang a large "bed net" above the center of a bed and either tuck the edges under the mattress or make sure it is large enough such that it touches the ground. ITNs are beneficial towards pregnancy outcomes in malaria-endemic regions in Africa but more data is needed in Asia and Latin America. Plasmodium falciparum Plasmodium falciparum

1197-414: A consistent supply of microscopy slides and stains. In places where microscopy is unavailable, malaria is diagnosed with RDTs, rapid antigen tests that detect parasite proteins in a fingerstick blood sample. A variety of RDTs are commercially available, targeting the parasite proteins histidine rich protein 2 (HRP2, detects P. falciparum only), lactate dehydrogenase , or aldolase . The HRP2 test

1330-506: A female Anopheles mosquito during a blood meal. The time of appearance of the symptoms from infection (called incubation period ) is shortest for P. falciparum among Plasmodium species. An average incubation period is 11 days, but may range from 9 to 30 days. In isolated cases, prolonged incubation periods as long as 2, 3 or even 8 years have been recorded. Pregnancy and co-infection with HIV are important conditions for delayed symptoms. Parasites can be detected from blood samples by

1463-411: A female anopheline mosquito to humans in 1898. In 1897, William H. Welch created the name Plasmodium falciparum , which ICZN formally adopted in 1954. P. falciparum assumes several different forms during its life cycle. The human-infective stage are sporozoites from the salivary gland of a mosquito . The sporozoites grow and multiply in the liver to become merozoites . These merozoites invade

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1596-472: A greater likelihood of complications and death. Malaria infection affects the immune responses following vaccination for various diseases. For example, malaria suppresses immune responses to polysaccharide vaccines. A potential solution is to give curative treatment before vaccination in areas where malaria is present. Due to the non-specific nature of malaria symptoms, diagnosis is typically suspected based on symptoms and travel history, then confirmed with

1729-491: A high score in a global comparison of indicators of Water Cooperation prepared by international think-tank Strategic Foresight Group . OMVS has a score of 91 in the Water Cooperation Quotient, which examines active cooperation by riparian countries in the management of water resources using 10 parameters, including legal, political, technical, environmental, economic and institutional aspects. The Quotient

1862-600: A human host when the mosquito takes a blood meal. The sporozoite then can move to the human host liver and infect hepatocytes . The profile of genes encoded by plasmodium that are employed in meiosis has some overlap with the profile of genes employed in meiosis in other more well studied organisms, but is more divergent and is lacking some components of the meiotic process found in other organisms. During plasmodium meiosis, recombination occurs between homologous chromosomes as in other organisms. A single anopheline mosquito can transmit hundreds of P. falciparum sporozoites in

1995-456: A laboratory test showing hemoglobin levels below 8 grams per deciliter of blood. In areas of the world with little to no malaria, the WHO recommends only testing people with possible exposure to malaria (typically travel to a malaria-endemic area) and unexplained fever. In sub-Saharan Africa, testing is low, with only about one in four (28%) of children with a fever receiving medical advice or

2128-488: A laboratory test to detect the presence of the parasite in the blood (parasitological test). In areas where malaria is common, the World Health Organization (WHO) recommends clinicians suspect malaria in any person who reports having fevers, or who has a current temperature above 37.5 °C without any other obvious cause. Malaria should be suspected in children with signs of anemia : pale palms or

2261-534: 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. 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

2394-559: A large number of RBCs sequentially without coordinated intervals, which is not seen in other malarial parasites. P. falciparum is therefore responsible for almost all severe human illnesses and deaths due to malaria, in a condition called pernicious or complicated or severe malaria. Complicated malaria occurs more commonly in children under age 5, and sometimes in pregnant women (a condition specifically called pregnancy-associated malaria ). Women become susceptible to severe malaria during their first pregnancy. Susceptibility to severe malaria

2527-636: A less pronounced and almost continuous fever. 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. Travellers taking preventative malaria medications may develop symptoms once they stop taking the drugs. Severe malaria is usually caused by P. falciparum (often referred to as falciparum malaria). Symptoms of falciparum malaria arise 9–30 days after infection. Individuals with cerebral malaria frequently exhibit neurological symptoms, including abnormal posturing , nystagmus , conjugate gaze palsy (failure of

2660-435: 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. 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

2793-437: A ookinete (4N) (see Figure: Life cycle of plasmodium). The ookinete that differentiates from the zygote is a highly mobile stage that invades the mosquito midgut. The ookinetes can undergo meiosis involving two meiotic divisions leading to the release of haploid sporozoites (see Figure). The sporozoite is an elongated crescent shaped invasive stage. These sporozoites may migrate to the mosquito’s salivary glands and can enter

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2926-564: A part of miasma theory ; the disease was formerly called ague or marsh fever due to its association with swamps and marshland. The term appeared in English at least as early as 1768. Malaria was once common in most of Europe and North America, where it is no longer endemic, though imported cases do occur. The scientific study of malaria is called malariology. Adults with malaria tend to experience chills and fever—classically in periodic intense bouts lasting around six hours, followed by

3059-530: A period of sweating and fever relief—as well as headache, fatigue, abdominal discomfort, and muscle pain . Children tend to have more general symptoms: fever, cough, vomiting, and diarrhea. Initial manifestations of the disease—common to all malaria species—are similar to flu-like symptoms , and can resemble other conditions such as sepsis , gastroenteritis , and viral diseases . The presentation may include headache , fever , shivering , joint pain , vomiting , hemolytic anemia , jaundice , hemoglobin in

3192-408: A phenomenon called recrudescence, is often seen in survivors. Recrudescence can occur even after successful antimalarial medication. It may take a few months or even several years. In some individuals, it takes as along as three years. In isolated cases, the duration can reach or exceed 10 years. It is also a common incident among pregnant women. P. falciparum is endemic in 84 countries, and

3325-434: A plastid, an apicoplast , similar to plant chloroplasts , which they probably acquired by engulfing (or being invaded by) a eukaryotic alga and retaining the algal plastid as a distinctive organelle encased within four membranes . The apicoplast is involved in the synthesis of lipids and several other compounds and provides an attractive drug target. During the asexual blood stage of infection, an essential function of

3458-575: 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

3591-635: A rapid diagnostic test in 2021. There was a 10-percentage point gap in testing between the richest and the poorest children (33% vs 23%). Additionally, a greater proportion of children in Eastern and Southern Africa (36%) were tested than in West and Central Africa (21%). According to UNICEF, 61% of children with a fever were taken for advice or treatment from a health facility or provider in 2021. Disparities are also observed by wealth, with an 18 percentage point difference in care-seeking behaviour between children in

3724-483: A schizont. This process is called schizogony. A schizont contains tens of thousands of nuclei. From the surface of the schizont, tens of thousands of haploid (1n) daughter cells called merozoites emerge. The liver stage can produce up to 90,000 merozoites, which are eventually released into the bloodstream in parasite-filled vesicles called merosomes. Merozoites use the apicomplexan invasion organelles ( apical complex , pellicle and surface coat) to recognize and enter

3857-466: A short time, and a "thin film" of blood, allowing them to clearly see individual parasites and identify the infecting Plasmodium species. Under typical field laboratory conditions, a microscopist can detect parasites when there are at least 100 parasites per microliter of blood, which is around the lower range of symptomatic infection. Microscopic diagnosis is relatively resource intensive, requiring trained personnel, specific equipment, electricity, and

3990-457: A single bite under experimental conditions, but, in nature the number is generally less than 80. The sporozoites do not enter the blood stream directly, but rather remain in the skin for two to three hours. About 15–20% of the sporozoites enter the lymphatic system, where they activate dendritic cells , which send them for destruction by T lymphocytes ( CD8+ T cells ). At 48 hours after infection, Plasmodium -specific CD8+ T cells can be detected in

4123-595: A small proportion of public expenditure on health. In contrast, a similar programme in Tanzania would cost an estimated one-fifth of the public health budget. In 2021, the World Health Organization confirmed that China has eliminated malaria. In 2023, the World Health Organization confirmed that Azerbaijan , Tajikistan , and Belize have eliminated malaria. In areas where malaria is common, children under five years old often have anaemia , which

Organisation pour la mise en valeur du fleuve Sénégal - Misplaced Pages Continue

4256-518: A way past the net. Insecticide-treated nets (ITNs) are estimated to be twice as effective as untreated nets and offer greater than 70% protection compared with no net. Between 2000 and 2008, the use of ITNs saved the lives of an estimated 250,000 infants in Sub-Saharan Africa. According to UNICEF, only 36% of households had sufficient ITNs for all household members in 2019. In 2000, 1.7 million (1.8%) African children living in areas of

4389-428: Is P. praefalciparum , a parasite of gorillas , as supported by mitochondrial , apicoplastic and nuclear DNA sequences. These two species are closely related to the 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. Levels of genetic polymorphism are extremely low within

4522-457: Is haploid (one set of chromosomes) during its reproductive stages in human blood and liver. When a mosquito takes a blood meal from a plasmodium infected human host, this meal may include haploid micro gametes and macro gametes . Such gametes can fuse within the mosquito to form a diploid (2N) plasmodium zygote , the only diploid stage in the life cycle of these parasites. The zygote can undergo another round of chromosome replication to form

4655-718: Is a stub . You can help Misplaced Pages by expanding it . This Senegal -related article is a stub . You can help Misplaced Pages by expanding it . This article about an international organization is a stub . You can help Misplaced Pages by expanding it . Malaria Malaria is a mosquito-borne infectious disease that affects vertebrates and Anopheles mosquitoes. Human malaria causes symptoms that typically include fever , fatigue , vomiting , and headaches . In severe cases, it can cause jaundice , seizures , coma , or death . Symptoms usually begin 10 to 15 days after being bitten by an infected Anopheles mosquito . If not properly treated, people may have recurrences of

4788-441: Is a unicellular protozoan parasite of humans , and the deadliest species of Plasmodium that causes malaria in humans. The parasite is transmitted through the bite of a female Anopheles mosquito and causes the disease's most dangerous form, falciparum malaria. P. falciparum is therefore regarded as the deadliest parasite in humans. It is also associated with the development of blood cancer ( Burkitt's lymphoma ) and

4921-479: Is a feature of blackwater fever , where haemoglobin from lysed red blood cells leaks into the urine. Infection with P. 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. An enlarged spleen , enlarged liver or both of these , severe headache, low blood sugar , and haemoglobin in

5054-402: Is also elongated measuring about 18–24 μm. An oocyst is rounded and can grow up to 80 μm in diameter. Microscopic examination of a blood film reveals only early (ring-form) trophozoites and gametocytes that are in the peripheral blood. Mature trophozoites or schizonts in peripheral blood smears, as these are usually sequestered in the tissues. On occasion, faint, comma-shaped, red dots are seen on

5187-429: Is approximately 48 hours. This gives rise to the characteristic clinical manifestations of falciparum malaria, such as fever and chills, corresponding to the synchronous rupture of the infected erythrocytes. Some merozoites differentiate into sexual forms, male and female gametocytes . These gametocytes take roughly 7–15 days to reach full maturity, through the process called gametocytogenesis. These are then taken up by

5320-518: Is associated with potentially life-threatening conditions about as often as with a diagnosis of P. falciparum infection. P. vivax proportionally is more common outside Africa. Some cases have been documented of human infections with several species of Plasmodium from higher apes , but except for P. knowlesi —a zoonotic species that causes malaria in macaques —these are mostly of limited public health importance. The Anopheles mosquitos initially get infected by Plasmodium by taking

5453-453: Is based on the level of resistance to the constituents in the combination. Artemisinin and its derivatives are not appropriate for monotherapy. As second-line antimalarial treatment, when initial treatment does not work, an alternative ACT known to be effective in the region is recommended, such as artesunate plus tetracycline or doxycycline or clindamycin , and quinine plus tetracycline or doxycycline or clindamycin. Any of these combinations

Organisation pour la mise en valeur du fleuve Sénégal - Misplaced Pages Continue

5586-418: Is calculated on a scale of 0 to 100, with 100 being the best performance. High performance in the Water Cooperation Quotient also means low risk of war between countries in the concerned river basin. This Guinea -related article is a stub . You can help Misplaced Pages by expanding it . This Mali -related article is a stub . You can help Misplaced Pages by expanding it . This Mauritania -related article

5719-470: Is caused by oxygen deprivation (hypoxia) due to inflammatory cytokine production and vascular leakage induced by the merozoites. Among the surviving individuals, persistent medical conditions such as neurological impairment, intellectual disability , and behavioural problems exist. Among them, epilepsy is the most common condition, and cerebral malaria is the leading cause of acquired epilepsy among African children. The reappearance of falciparum symptom,

5852-446: Is caused by six Plasmodium species: P. falciparum , P. malariae , P. ovale curtisi , P. ovale wallikeri , P. vivax and P. knowlesi . Among those infected, P. falciparum is the most common species identified (~75%) followed by P. vivax (~20%). Although P. falciparum traditionally accounts for the majority of deaths, recent evidence suggests that P. vivax malaria

5985-401: Is classified as a Group 2A (probable) carcinogen . The species originated from the malarial parasite Laverania found in gorillas , around 10,000 years ago. Alphonse Laveran was the first to identify the parasite in 1880, and named it Oscillaria malariae . Ronald Ross discovered its transmission by mosquito in 1897. Giovanni Battista Grassi elucidated the complete transmission from

6118-465: Is deemed severe when any of the following criteria are present, otherwise it is considered uncomplicated. Cerebral malaria is defined as a severe P. falciparum -malaria presenting with neurological symptoms, including coma (with a Glasgow coma scale less than 11, or a Blantyre coma scale less than 3), or with a coma that lasts longer than 30 minutes after a seizure. Methods used to prevent malaria include medications, mosquito elimination and

6251-515: Is endemic, other, less virulent plasmodial species predominate. Falciparum malaria was familiar to the ancient Greeks , who gave the general name πυρετός ( pyretós ) "fever". Hippocrates (c. 460–370 BCE) gave several descriptions on tertian fever and quartan fever . It was prevalent throughout the ancient Egyptian and Roman civilizations. It was the Romans who named the disease "malaria"— mala for bad, and aria for air, as they believed that

6384-561: Is found in all continents except Europe. Historically, it was present in most European countries, but improved health conditions led to the disappearance in the early 20th century. The only European country where it used to be historically prevalent, and from where we got the name malaria, Italy had been declared malaria-eradicated country. In 1947, the Italian government launched the National Malaria Eradication Program, and following, an anti-mosquito campaign

6517-531: Is insufficient evidence that mosquito repellents can prevent malaria infection. Insecticide-treated nets (ITNs) and indoor residual spraying (IRS) are effective, have been commonly used to prevent malaria, and their use has contributed significantly to the decrease in malaria in the 21st century. ITNs and IRS may not be sufficient to eliminate the disease, as these interventions depend on how many people use nets, how many gaps in insecticide there are (low coverage areas), if people are not protected when outside of

6650-496: Is likely that the development of extensive agriculture increased mosquito population densities by giving rise to more breeding sites, which may have triggered the evolution and expansion of P. falciparum . P. falciparum does not have a fixed structure but undergoes continuous change during the course of its life cycle. A sporozoite is spindle-shaped and 10–15 μm long. In the liver it grows into an ovoid schizont of 30–70 μm in diameter. Each schizont produces merozoites, each of which

6783-419: Is mediated by erythrocyte membrane proteins, which are produced by the schizonts and trophozoites inside the erythrocytes and are displayed on the erythrocyte membrane. PfEMP1 is the most important, capable of acting as both an antigen and an adhesion molecule. The clinical symptoms of falciparum malaria are produced by the rupture and destruction of erythrocytes by the merozoites. High fever, called paroxysm,

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6916-451: Is not available. In areas where the disease is common, malaria should be confirmed if possible before treatment is started due to concerns of increasing drug resistance . Resistance among the parasites has developed to several antimalarial medications; for example, chloroquine -resistant P. falciparum has spread to most malarial areas, and resistance to artemisinin has become a problem in some parts of Southeast Asia . The disease

7049-452: Is recommended. Quinine is an acceptable alternative if parenteral artesunate is not available. For children, especially in the malaria-endemic areas of Africa, artesunate IV or IM, quinine (IV infusion or divided IM injection), and artemether IM are recommended. Parenteral antimalarials should be administered for a minimum of 24 hours, irrespective of the patient's ability to tolerate oral medication earlier. Thereafter, complete treatment

7182-432: Is reduced in subsequent pregnancies due to increased antibody levels against variant surface antigens that appear on infected erythrocytes. But increased immunity in the mother increases susceptibility to malaria in newborn babies. P. falciparum works via sequestration, a process by which group of infected RBCs are clustered, which is not exhibited by any other species of malarial parasites. The mature schizonts change

7315-400: Is relatively invisible to immune surveillance. However, circulating infected blood cells are destroyed in the spleen . To avoid this fate, the P. falciparum parasite displays adhesive proteins on the surface of the infected blood cells, causing the blood cells to stick to the walls of small blood vessels, thereby sequestering the parasite from passage through the general circulation and

7448-402: Is released from the salivary glands through the proboscis of the mosquito to enter through the skin during feeding. The mosquito saliva contains antihaemostatic and anti-inflammatory enzymes that disrupt blood clotting and inhibit the pain reaction. Typically, each infected bite contains 20–200 sporozoites. A proportion of sporozoites invade liver cells ( hepatocytes ). The sporozoites move in

7581-442: Is roughly 1.5 μm in length and 1 μm in diameter. In the erythrocyte the merozoite form a ring-like structure, becoming a trophozoite. A trophozoite feeds on the haemoglobin and forms a granular pigment called haemozoin . Unlike those of other Plasmodium species, the gametocytes of P. falciparum are elongated and crescent-shaped, by which they are sometimes identified. A mature gametocyte is 8–12 μm long and 3–6 μm wide. The ookinete

7714-449: Is sometimes due to malaria. Giving children with anaemia in these areas preventive antimalarial medication improves red blood cell levels slightly but does not affect the risk of death or need for hospitalisation. Vector control refers to methods used to decrease malaria by reducing the levels of transmission by mosquitoes. For individual protection, the most effective insect repellents are based on DEET or picaridin . However, there

7847-408: Is spread exclusively through bites of infected female Anopheles mosquitoes. The mosquito bite introduces the parasites from the mosquito's saliva into a person's blood. The parasites travel to the liver , where they mature and reproduce. Five species of Plasmodium commonly infect humans. The three species associated with more severe cases are P. falciparum (which is responsible for

7980-848: Is the most basic indication. The fever has a characteristic cycle of hot stage, cold stage and sweating stages. Since each erythrocytic schizogony takes a cycle of 48 hours, i.e., two days, the febrile symptom appears every third day. This is the reason the infection is classically named tertian malignant fever (tertian, a derivative of Latin word that means "third"). The most common symptoms are fever (>92% of cases), chills (79%), headaches (70%), and sweating (64%). Dizziness , malaise , muscle pain , abdominal pain , nausea , vomiting , mild diarrhea , and dry cough are also generally associated. High heartrate , jaundice , pallor , orthostatic hypotension , enlarged liver , and enlarged spleen are also diagnosed. The insoluble β-hematin crystals, haemozoin, produced from digestion of haemoglobin of

8113-463: Is to be given for 7 days. For pregnant women, the recommended first-line treatment during the first trimester is quinine plus clindamycin for 7 days. Artesunate plus clindamycin for 7 days is indicated if this treatment fails. For travellers returning to nonendemic countries, atovaquone / proguanil , artemether/lumefantrineany and quinine plus doxycycline or clindamycin are recommended. For adults, intravenous (IV) or intramuscular (IM) artesunate

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8246-425: Is typical) to several years. After a period of dormancy, they reactivate and produce merozoites. Hypnozoites are responsible for long incubation and late relapses in P. vivax infections, although their existence in P. ovale is uncertain. The parasite is relatively protected from attack by the body's immune system because for most of its human life cycle it resides within the liver and blood cells and

8379-413: Is typically attributed to treatment failure. People may develop some immunity when exposed to frequent infections. Malaria infection develops via two phases: one that involves the liver (exoerythrocytic phase), and one that involves red blood cells, or erythrocytes (erythrocytic phase). When an infected mosquito pierces a person's skin to take a blood meal, sporozoites in the mosquito's saliva enter

8512-765: Is widely used in Africa, where P. falciparum predominates. However, since HRP2 persists in the blood for up to five weeks after an infection is treated, an HRP2 test sometimes cannot distinguish whether someone currently has malaria or previously had it. Additionally, some P. falciparum parasites in the Amazon region lack the HRP2 gene, complicating detection. RDTs are fast and easily deployed to places without full diagnostic laboratories. However they give considerably less information than microscopy, and sometimes vary in quality from producer to producer and lot to lot. Serological tests to detect antibodies against Plasmodium from

8645-512: Is widespread in the tropical and subtropical regions that exist in a broad band around the equator . This includes much of sub-Saharan Africa , Asia , and Latin America . In 2022, some 249 million cases of malaria worldwide resulted in an estimated 608,000 deaths, with 80 percent being five years old or less. Around 95% of the cases and deaths occurred in sub-Saharan Africa. Rates of disease decreased from 2010 to 2014, but increased from 2015 to 2021. According to UNICEF, nearly every minute,

8778-409: The P. falciparum genome compared to that of closely related, ape infecting species of Plasmodium (including P. praefalciparum ). This suggests that the origin of P. falciparum in humans is recent, as a single P. praefalciparum strain became capable of infecting humans. The genetic information of P. falciparum has signaled a recent expansion that coincides with the agricultural revolution. It

8911-411: The bone marrow for 11 days, then return to the blood circulation to await uptake by the bite of another mosquito. Once inside a mosquito, the gametocytes undergo sexual reproduction, and eventually form daughter sporozoites that migrate to the mosquito's salivary glands to be injected into a new host when the mosquito bites. The liver infection causes no symptoms; all symptoms of malaria result from

9044-715: The erythrocytes (red blood cells) to form trophozoites , schizonts and gametocytes , during which the symptoms of malaria are produced. In the mosquito, the gametocytes undergo sexual reproduction to a zygote , which turns into ookinete . Ookinete forms oocytes from which sporozoites are formed. In 2022, some 249 million cases of malaria worldwide resulted in an estimated 608,000 deaths, with 80 percent being 5 years old or less. Nearly all malarial deaths are caused by P. falciparum , and 95% of such cases occur in Africa . In Sub-Saharan Africa, almost 100% of cases were due to P. falciparum , whereas in most other regions where malaria

9177-443: The lymph nodes connected to the skin cells. Most of the sporozoites remaining in the skin tissue are subsequently killed by the innate immune system . The sporozoite glycoprotein specifically activates mast cells . The mast cells then produce signaling molecules such as TNFα and MIP-2, which activate cell eaters (professional phagocytes) such as neutrophils and macrophages . Only a small number (0.5-5%) of sporozoites enter

9310-491: The polymerase chain reaction to detect the parasite's DNA have been developed, but they are not widely used in areas where malaria is common, due to their cost and complexity. The risk of disease can be reduced by preventing mosquito bites through the use of mosquito nets and insect repellents or with mosquito-control measures such as spraying insecticides and draining standing water . Several medications are available to prevent malaria for travellers in areas where

9443-459: The var , rif , and stevor families. Within the genome, there exist 59 var , 149 rif , and 28 stevor genes, along with multiple pseudogenes and truncations. It is estimated that 551, or roughly 10%, of the predicted nuclear-encoded proteins are targeted to the apicoplast , while 4.7% of the proteome is targeted to the mitochondria. Humans are the intermediate hosts in which asexual reproduction occurs, and female anopheline mosquitos are

9576-424: The 10th day after infection (pre-patent period). Within the mosquito midgut, the female gamete maturation process entails slight morphological changes, becoming more enlarged and spherical. The male gametocyte undergoes a rapid nuclear division within 15 minutes, producing eight flagellated microgametes by a process called exflagellation. The flagellated microgamete fertilizes the female macrogamete to produce

9709-459: The 1970s. It is estimated that approximately 2.4 billion people are at constant risk of infection. In 1640, Huan del Vego first employed the tincture of the cinchona bark for treating malaria; the native Indians of Peru and Ecuador had been using it even earlier for treating fevers. Thompson (1650) introduced this " Jesuits ' bark" to England . Its first recorded use there was by John Metford of Northampton in 1656. Morton (1696) presented

9842-832: The Nobel Prize in Chemistry in 1965. Attempts to make synthetic antimalarials began in 1891. Atabrine , developed in 1933, was used widely throughout the Pacific in World War II, but was unpopular because of its adverse effects. In the late 1930s, the Germans developed chloroquine , which went into use in the North African campaigns. Creating a secret military project called Project 523 , Mao Zedong encouraged Chinese scientists to find new antimalarials after seeing

9975-603: The Nobel Prize in Physiology or Medicine in 1902. Under controversial circumstances, only Ross was selected for the award. 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 . 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 meaning "to see" or "to know." The species name

10108-473: The OMVS. Guinea returned to the organisation in 2006. The OMVS aims to promote self-sufficiency in food security, to improve the income of the local populations, and to preserve the natural ecosystems. The area has a total population of 35 million inhabitants, of whom 12 million live in the river basin, and where malaria control intervention coverage is among the lowest in the world. OMVS has recently received

10241-468: The RBCs is the main agent that affect body organs. Acting as a blood toxin, haemozoin-containing RBCs cannot be attacked by phagocytes during immune response to malaria. The phagocytes can ingest free haemozoins liberated after the rupture of RBCs by which they are induced to initiate chains of inflammatory reaction that results in increased fever. It is the haemozoin that is deposited in body organs such as

10374-687: The South-East Asia, and 2% in the Eastern Mediterranean. Nigeria has the highest incidence, with 27% of the total global cases. Outside Africa, India has the highest incidence, with 4.5% of the global burden. Europe is regarded as a malaria-free region. Historically, the parasite and its disease had been most well known in Europe. But medical programmes since the early 20th century, such as insecticide spraying, drug therapy and environmental engineering, resulted in complete eradication in

10507-405: The absence of Duffy antigens on red blood cells. The impact of sickle cell trait on malaria immunity illustrates some evolutionary trade-offs that have occurred because of endemic malaria. Sickle cell trait causes a change in the haemoglobin molecule in the blood. Normally, red blood cells have a very flexible, biconcave shape that allows them to move through narrow capillaries ; however, when

10640-535: The apicoplast is to produce the isoprenoid precursors isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP) via the MEP (non-mevalonate) pathway . In 1995 the Malaria Genome Project was set up to sequence the genome of P. falciparum . The genome of its mitochondrion was reported in 1995, that of the nonphotosynthetic plastid known as the apicoplast in 1996, and the sequence of

10773-418: The blood have been developed, but are not used for malaria diagnosis due to their relatively poor sensitivity and specificity. Highly sensitive nucleic acid amplification tests have been developed, but are not used clinically due to their relatively high cost, and poor specificity for active infections. Malaria is classified into either "severe" or "uncomplicated" by the World Health Organization (WHO). It

10906-412: The blood in the same stage of development. This precise clocking mechanism has been shown to be dependent on the human host's own circadian rhythm . Within the erythrocyte, the parasite metabolism depends on the digestion of haemoglobin . The clinical symptoms of malaria such as fever, anemia, and neurological disorder are produced during the blood stage. The parasite can also alter the morphology of

11039-454: The blood stream into the liver. In the liver, the activated CD8+ T cells from the lymph bind the sporozoites through the circumsporozoite protein (CSP). Antigen presentation by dendritic cells in the skin tissue to T cells is also a crucial process. From this stage onward, the parasites produce different proteins that help suppress communication of the immune cells. Even at the height of the infection, when red blood cells (RBCs) are ruptured,

11172-430: The bloodstream and migrate to the liver where they infect hepatocytes, multiplying asexually and asymptomatically for a period of 8–30 days. After a potential dormant period in the liver, these organisms differentiate to yield thousands of merozoites, which, following rupture of their host cells, escape into the blood and infect red blood cells to begin the erythrocytic stage of the life cycle. The parasite escapes from

11305-405: The bloodstream by gliding , which is driven by a motor made up of the proteins actin and myosin beneath their plasma membrane . Entering the hepatocytes, the parasite loses its apical complex and surface coat, and transforms into a trophozoite . Within the parasitophorous vacuole of the hepatocyte, it undergoes 13–14 rounds of mitosis which produce a syncytial cell ( coenocyte ) called

11438-540: The bloodstream. In the blood, the merozoites rapidly invade individual red blood cells , replicating over 24–72 hours to form 16–32 new merozoites. The infected red blood cell lyses, and the new merozoites infect new red blood cells, resulting in a cycle that continuously amplifies the number of parasites in an infected person. Over rounds of this infection cycle, a small portion of parasites do not replicate, but instead develop into early sexual stage parasites called male and female " gametocytes ". These gametocytes develop in

11571-408: The brain, they contribute to coma . In the placenta they contribute to low birthweight and preterm labor, and increase the risk of abortion and stillbirth. The destruction of red blood cells during infection often results in anemia, exacerbated by reduced production of new red blood cells during infection. Only female mosquitoes feed on blood; male mosquitoes feed on plant nectar and do not transmit

11704-769: The casualties in the Vietnam War. Tu Youyou discovered artemisinin in the 1970s from sweet wormwood ( Artemisia annua ). This drug became known to Western scientists in the late 1980s and early 1990s and is now a standard treatment. Tu won the Nobel Prize in Physiology or Medicine in 2015. According to WHO guidelines 2010, artemisinin-based combination therapies (ACTs) are the recommended first-line antimalarial treatments for uncomplicated malaria caused by P. falciparum . WHO recommends combinations such as artemether/lumefantrine , artesunate/amodiaquine , artesunate/mefloquine , artesunate/sulfadoxine/pyrimethamine , and dihydroartemisinin/piperaquine . The choice of ACT

11837-434: The cause, recurrence can be classified as either recrudescence , relapse , or reinfection. Recrudescence is when symptoms return after a symptom-free period due to failure to remove blood-stage parasites by adequate treatment. Relapse is when symptoms reappear after the parasites have been eliminated from the blood but have persisted as dormant hypnozoites in liver cells. Relapse commonly occurs between 8 and 24 weeks after

11970-400: The clinical symptom is indicated by coma and diagnosis by high level of merozoites in the peripheral blood samples. It is the deadliest form of malaria, and to it are attributed to 0.2 million to over a million annual deaths throughout the ages. Most deaths are of children of below 5 years of age. It occurs when the merozoites invade the brain and causes brain damage of varying degrees. Death

12103-400: The definitive hosts harbouring the sexual reproduction stage. Infection in humans begins with the bite of an infected female Anopheles mosquito. Out of about 460 species of Anopheles mosquito , more than 70 species transmit falciparum malaria. Anopheles gambiae is one of the best known and most prevalent vectors, particularly in Africa. The infective stage called the sporozoite

12236-521: The development of respiratory distress , which occurs in up to 25% of adults and 40% of children with severe P. 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. Coinfection of HIV with malaria increases mortality. Kidney failure

12369-509: The disease in the long run, but the initial costs required are out of reach of many of the world's poorest people. There is a wide difference in the costs of control (i.e. maintenance of low endemicity) and elimination programs between countries. For example, in China—whose government in 2010 announced a strategy to pursue malaria elimination in the Chinese provinces —the required investment is

12502-578: The disease is common. Occasional doses of the combination medication sulfadoxine/pyrimethamine are recommended in infants and after the first trimester of pregnancy in areas with high rates of malaria. As of 2023, two malaria vaccines have been endorsed by the World Health Organization . The recommended treatment for malaria is a combination of antimalarial medications that includes artemisinin . The second medication may be either mefloquine , lumefantrine , or sulfadoxine/pyrimethamine. Quinine , along with doxycycline , may be used if artemisinin

12635-475: The disease months later. In those who have recently survived an infection, reinfection usually causes milder symptoms. This partial resistance disappears over months to years if the person has no continuing exposure to malaria. The mosquito vector is itself harmed by Plasmodium infections, causing reduced lifespan. Human malaria is caused by single-celled microorganisms of the Plasmodium group. It

12768-502: The disease was spread by contaminated air, or miasma . 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

12901-643: The disease, which increases the victim's likelihood of death. After invading the erythrocyte, the parasite loses its specific invasion organelles (apical complex and surface coat) and de-differentiates into a round trophozoite located within a parasitophorous vacuole. The trophozoite feeds on the haemoglobin of the erythrocyte, digesting its proteins and converting (by biocrystallization ) the remaining heme into insoluble and chemically inert β-hematin crystals called haemozoin. The young trophozoite (or "ring" stage, because of its morphology on stained blood films) grows substantially before undergoing multiplication. At

13034-462: The disease. Females of the mosquito genus Anopheles prefer to feed at night. They usually start searching for a meal at dusk, and continue through the night until they succeed. However, in Africa, due to the extensive use of bed nets, they began to bite earlier, before bed-net time. Malaria parasites can also be transmitted by blood transfusions , although this is rare. Symptoms of malaria can recur after varying symptom-free periods. Depending upon

13167-476: The erythrocyte surface. These dots are Maurer's cleft and are secretory organelles that produce proteins and enzymes essential for nutrient uptake and immune evasion processes. The apical complex, which is actually a combination of organelles, is an important structure. It contains secretory organelles called rhoptries and micronemes, which are vital for mobility, adhesion, host cell invasion, and parasitophorous vacuole formation. As an apicomplexan , it harbours

13300-414: The erythrocyte, causing knobs on the erythrocyte membrane. Infected erythrocytes are often sequestered in various human tissues or organs, such as the heart, liver and brain. This is caused by parasite-derived cell surface proteins being present on the erythrocyte membrane, and it is these proteins that bind to receptors on human cells. Sequestration in the brain causes cerebral malaria, a very severe form of

13433-494: The eyes to turn together in the same direction), opisthotonus , seizures , or coma . 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 - suggesting that 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

13566-492: The first detailed description of the clinical picture of malaria and of its treatment with cinchona. Gize (1816) studied the extraction of crystalline quinine from the cinchona bark and Pelletier and Caventou (1820) in France extracted pure quinine alkaloids , which they named quinine and cinchonine . The total synthesis of quinine was achieved by American chemists R.B. Woodward and W.E. Doering in 1944. Woodward received

13699-429: The first nuclear chromosome (chromosome 2) in 1998. The sequence of chromosome 3 was reported in 1999 and the entire genome was reported on 3 October 2002. The roughly 24-megabase genome is extremely AT-rich (about 80%) and is organised into 14 chromosomes. Just over 5,300 genes were described. Many genes involved in antigenic variation are located in the subtelomeric regions of the chromosomes. These are divided into

13832-442: The frequency with which malaria parasites complete their life cycle in the cell. Individuals who are homozygous (with two copies of the abnormal haemoglobin beta allele ) have sickle-cell anaemia , while those who are heterozygous (with one abnormal allele and one normal allele) experience resistance to malaria without severe anaemia. Although the shorter life expectancy for those with the homozygous condition would tend to disfavour

13965-675: The hepatocytes is aided by thrombospondin-related anonymous protein (TRAP). TRAP and other secretory proteins (including sporozoite microneme protein essential for cell traversal 1, SPECT1 and SPECT2) from microneme allow the sporozoite to move through the blood, avoiding immune cells and penetrating hepatocytes. During erythrocyte invasion, merozoites release merozoite cap protein-1 (MCP1), apical membrane antigen 1 (AMA1), erythrocyte-binding antigens (EBA), myosin A tail domain interacting protein (MTIP), and merozoite surface proteins (MSPs). Of these MSPs, MSP1 and MSP2 are primarily responsible for avoiding immune cells. The virulence of P. falciparum

14098-399: 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. Malaria has several serious complications , including

14231-429: The home, and an increase in mosquitoes that are resistant to insecticides. Modifications to people's houses to prevent mosquito exposure may be an important long term prevention measure. Mosquito nets help keep mosquitoes away from people and reduce infection rates and transmission of malaria. Nets are not a perfect barrier and are often treated with an insecticide designed to kill the mosquito before it has time to find

14364-410: The host erythrocyte ( red blood cell ). The merozoites first bind to the erythrocyte in a random orientation. It then reorients such that the apical complex is in proximity to the erythrocyte membrane. The parasite forms a parasitophorous vacuole, to allow for its development inside the erythrocyte . This infection cycle occurs in a highly synchronous fashion, with roughly all of the parasites throughout

14497-399: The immune signals are not strong enough to activate macrophages or natural killer cells . Although P. falciparum is easily recognized by the human immune system while in the bloodstream, it evades immunity by producing over 2,000 cell membrane antigens. The initial infective stage sporozoites produce circumsporozoite protein (CSP), which binds to hepatocytes. Binding to and entering into

14630-423: The infection of red blood cells. Symptoms develop once there are more than around 100,000 parasites per milliliter of blood. Many of the symptoms associated with severe malaria are caused by the tendency of P. falciparum to bind to blood vessel walls, resulting in damage to the affected vessels and surrounding tissue. Parasites sequestered in the blood vessels of the lung contribute to respiratory failure . In

14763-502: The initial symptoms and is often seen in P. vivax and P. ovale infections. P. vivax malaria cases in temperate areas often involve overwintering by hypnozoites, with relapses beginning the year after the mosquito bite. Reinfection means that parasites were eliminated from the entire body but new parasites were then introduced. Reinfection cannot readily be distinguished from relapse and recrudescence, although recurrence of infection within two weeks of treatment ending

14896-634: The liver undetected by wrapping itself in the cell membrane of the infected host liver cell. Within the red blood cells, the parasites multiply further, again asexually, periodically breaking out of their host cells to invade fresh red blood cells. Several such amplification cycles occur. Thus, classical descriptions of waves of fever arise from simultaneous waves of merozoites escaping and infecting red blood cells. Some P. vivax sporozoites do not immediately develop into exoerythrocytic-phase merozoites, but instead, produce hypnozoites that remain dormant for periods ranging from several months (7–10 months

15029-431: 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. Lactic acid Lactic acid, a naturally produced levorotatory isomer, has been titled an attractant of mosquitoes for a long time. Lactic acid is predominantly produced by eccrine-sweat glands, creating

15162-504: The modified haemoglobin S molecules are exposed to low amounts of oxygen, or crowd together due to dehydration, they can stick together forming strands that cause the cell to distort into a curved sickle shape. In these strands, the molecule is not as effective in taking or releasing oxygen, and the cell is not flexible enough to circulate freely. In the early stages of malaria, the parasite can cause infected red cells to sickle, and so they are removed from circulation sooner. This reduces

15295-414: The mosquito. This discovery offers opportunity to look into what could be playing a role in this behavior changes on mosquito and also find out what they ingest when the foraged on the selected plants. In other studies it has been shown that sources of sugars and some secondary metabolites e.g ricinine, have contrasting effects in mosquito capacity to transmit the parasites malaria. Plasmodium falciparum

15428-659: 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 . However, his discovery was received with skepticism, mainly because by that time, leading physicians such as Theodor Albrecht Edwin Klebs and Corrado Tommasi-Crudeli claimed that they had discovered

15561-637: The parasite eventually disappears from that area, as happened in North America, Europe, and parts of the Middle East. However, unless the parasite is eliminated from the whole world, it could re-establish if conditions revert to a combination that favors the parasite's reproduction. Furthermore, the cost per person of eliminating anopheles mosquitoes rises with decreasing population density, making it economically unfeasible in some areas. Prevention of malaria may be more cost-effective than treatment of

15694-456: The prevention of bites. As of 2023, there are two malaria vaccines , approved for use in children by the WHO: RTS,S and R21 . The presence of malaria in an area requires a combination of high human population density, high Anopheles mosquito population density and high rates of transmission from humans to mosquitoes and from mosquitoes to humans. If any of these is lowered sufficiently,

15827-438: The primary source of energy and nutrients for their survival and other biological process such as host seeking for blood or searching for oviposition sites. Researchers have recently discovered that mosquitoes are very selective about their sugar meal sources. For example Anopheles mosquitos prefer some plants over others, specifically those containing compounds that hinder the development and survival of malaria parasites inside

15960-411: The richest (71%) and the poorest (53%) households. Malaria is usually confirmed by the microscopic examination of blood films or by antigen -based rapid diagnostic tests (RDT). Microscopy—i.e. examining Giemsa -stained blood with a light microscope —is the gold standard for malaria diagnosis. Microscopists typically examine both a "thick film" of blood, allowing them to scan many blood cells in

16093-507: The schizont stage, the parasite replicates its DNA multiple times and multiple mitotic divisions occur asynchronously. Cell division and multiplication in the erythrocyte is called erythrocytic schizogony. Each schizont forms 16-18 merozoites. The red blood cells are ruptured by the merozoites. The liberated merozoites invade fresh erythrocytes. A free merozoite is in the bloodstream for roughly 60 seconds before it enters another erythrocyte. The duration of one complete erythrocytic schizogony

16226-437: 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,

16359-403: The spleen and liver, as well as in kidneys and lungs, to cause their enlargement and discolouration. Because of this, haemozoin is also known as malarial pigment. Unlike other malarias, which show regular periodicity of fever, falciparum, though exhibiting a 48-hour cycle, usually presents as irregular bouts of fever . This difference is due the ability of P. falciparum merozoites to invade

16492-563: The spleen. The blockage of the microvasculature causes symptoms such as those in placental malaria. Sequestered red blood cells can breach the blood–brain barrier and cause cerebral malaria. Due to the high levels of mortality and morbidity caused by malaria—especially the P. falciparum species—it has placed the greatest selective pressure on the human genome in recent history. Several genetic factors provide some resistance to it including sickle cell trait , thalassaemia traits, glucose-6-phosphate dehydrogenase deficiency , and

16625-412: The surface properties of infected erythrocytes, causing them to stick to blood vessel walls (cytoadherence). This leads to obstruction of the microcirculation and results in dysfunction of multiple organs, such as the brain in cerebral malaria . Cerebral malaria is the most dangerous condition of any malarial infection and the most severe form of neurological disorders . According to the WHO definition,

16758-425: 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 P. vivax ), and quartan malaria by Haemamoeba malariae (now P. malariae ). 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,

16891-612: The trait's survival, the trait is preserved in malaria-prone regions because of the benefits provided by the heterozygous form. Liver dysfunction as a result of malaria is uncommon and usually only occurs in those with another liver condition such as viral hepatitis or chronic liver disease . The syndrome is sometimes called malarial hepatitis . While it has been considered a rare occurrence, malarial hepatopathy has seen an increase, particularly in Southeast Asia and India. Liver compromise in people with malaria correlates with

17024-415: The urine with kidney failure may occur. Complications may include spontaneous bleeding, coagulopathy , and shock . Malaria during pregnancy can cause stillbirths , infant mortality , miscarriage , and low birth weight , particularly in P. falciparum infection, but also with P. vivax . Malaria is caused by infection with parasites in the genus Plasmodium . In humans, malaria

17157-424: The urine , retinal damage , and convulsions . The classic symptom of malaria is paroxysm —a cyclical occurrence of sudden coldness followed by shivering and then fever and sweating, occurring every two days ( tertian fever ) in P. vivax and P. ovale infections, and every three days ( quartan fever ) for P. malariae . P. falciparum infection can cause recurrent fever every 36–48 hours, or

17290-401: The vast majority of malaria deaths), P. vivax , and P. knowlesi (a simian malaria that spills over into thousands of people a year). P. ovale and P. malariae generally cause a milder form of malaria. Malaria is typically diagnosed by the microscopic examination of blood using blood films , or with antigen-based rapid diagnostic tests . Methods that use

17423-427: The world where malaria is common were protected by an ITN. That number increased to 20.3 million (18.5%) African children using ITNs in 2007, leaving 89.6 million children unprotected and to 68% African children using mosquito nets in 2015. The percentage of children sleeping under ITNs in sub-Saharan Africa increased from less than 40% in 2011 to over 50% in 2021. Most nets are impregnated with pyrethroids ,

17556-423: Was implemented using DDT. The WHO declared Italy free of malaria in 1970. There were 247 million cases of malaria worldwide in 2021, resulting in an estimated 619,000 deaths. The infection is most prevalent in Africa, where 94% of malaria deaths occur. Children under five years of age are most affected, and 67% of malaria deaths occurred in this age group. 80% of the infection is found in Sub-Saharan Africa, 7% in

17689-587: Was introduced by an American physician William Henry Welch in 1897. It is derived from the Latin falx , meaning "sickle" and parum meaning "like or equal to another". P. falciparum is now generally accepted to have evolved from Laverania (a subgenus of Plasmodium found in apes) species present in gorilla in Western Africa. Genetic diversity indicates that the human protozoan emerged around 10,000 years ago. The closest relative of P. falciparum

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