Plasmodium vivax infection Malaria

Pamaquine was synthesized in 1952, this 8-aminoquinoline was the first drug capable of preventing the relapses in Plasmodium vivax malaria. Toxicological concerns led to restrictions in the use of Pamaquine. Primaquine another 8-aminoquinoline derivative has been used since 1950 s for the eradication of liver stages in course of Plasmodium vivax infections. 

Malaria is transmitted by the bite of an infected female Anopheles mosquito, one of the few species of the insect capable of carrying the human malaria parasite. The responsible protozoa ate from the genus P/asmodium of which only four of some 100 species can cause the disease in humans. The remaining species affect rodents, reptiles, monkeys, birds, and Hvestock. The species that infect humans are P/asmodium falciparum Plasmodium vivax Plasmodium malariae and Plasmodium ovale. Note that concomitant multiple malaria infections are commonly seen in endemic areas, a phenomenon that further compHcates choice of treatment. 

Plasmodium vivax, responsible for the most prevalent form of malaria (benign tertian), has an incubation period of 8—27 days (14 average). A variety seen in northern and northeastern Europe has an incubation period as long as 8—10 months. The disease can cause splenic mpture and anemia. Relapses (renewed manifestations of erythrocytic infection) can occur with this type of malaria. Overall, P. vivax is stiU susceptible to chloroquine however, resistant strains have been reported from Papua New Guinea and parts of Indonesia. Plasmodium malariae the cause of quartan malaria, has an incubation period of 15—30 days and its asexual cycle is 72 hours. This mildest form of malaria can cause nephritis in addition to the usual symptoms. It is a nonrelapsing type of malaria but the ted blood ceU infection can last for many years. No resistance to chloroquine by this plasmodium has been reported. Plasmodium ovale responsible for ovale tertian malaria, has an incubation period of 9—17 days (15 average). Relapses can occur in people infected with this plasmodium. No chloroquine resistance has been reported for this parasite. 

Human malaria is caused by four species of Plasmodium namely Plasmodium falciparum, P. vivax, P. malariae and P. ovale. P. vivax is mainly responsible for most of the infections (70%) which results in benign tertian malaria. In P. falciparum and P. vivax infections, the patient has fever with rigors every third day and termed as tertian. The other two, P. ovale and P. malariae are mild in nature in which fever develops every fourth day and termed as benign quartan. Symptoms and complications in P. falciparum malaria are more severe than P. vivax malaria. 

Ling J et al Randomized, placebo-controlled trial of atovaquone/proguanil for the prevention of Plasmodium falciparum or Plasmodium vivax malaria among migrants to Papua, Indonesia. Clin Infect Dis 2002 35 825. [PMID 12228819]... 

Four principal species from the genus Plasmodium cause natural human infection Plasmodium vivax, Plasmodium ovale, Plasmodium malariae, and Plasmodium falciparum. P. falciparum is the most lethal as it causes approximately 90% of malaria-related deaths (1). An additional species, Plasmodium knowlesi, which generally infects macaques, has also been shown increasingly to infect humans as well (4). As more sophisticated diagnostic tests are now able to easily distinguish one species of Plasmodium from another, it is thought that infection with P. knowlesi has heretofore been underreported because this species morphologically resembles other Plasmodium species in blood smears (5). 

The total dose of chloroquine base over 3 days should be approximately 25 mg/kg base. This is sufficient for Plasmodium malariae infection but, for Plasmodium vivax and Plasmodium ovale eradication of the hepatic parasites is necessary to prevent relapse, by giving ... 

Malaria is a vector-borne infectious disease caused by protozoan parasites. Human malaria is usually caused by the infection of Plasmodium falciparum, P. malariae, P. ovale, and P. vivax (Mendis et al, 2001). It is widespread in tropical and subtropical regions, including Asia, Africa, and parts of the Americas. Each year there are about 350-500 million cases of malaria, and more than 1 million people die (CDC, 2009). A series of gossypol derivatives with modified aldehydic groups and hydroxyl groups (Figs. 6.10 and 6.11) have been shown to inhibit the growth of P. falciparum (Razakantoanina et al, 2000 Royer et al, 1986). Table 6.3... 

The exact geographic distribution of the various species is not well documented however, it is reported that Plasmodium vivax is more prevalent in India, Pakistan, Bangladesh, Sri Lanka, and Central America, whereas P. falciparum is predominant in Africa, Haiti, Dominican Republic, the Amazon region of South America, and New Guinea. Both P. falciparum and P. vivax are prevalent in aU of Southeast Asia, South America, Middle East, North Africa, Ethiopia, Somalia, and Sudan. Most of the infections with P. ovale occur in Africa, and the distribution of P. malariae is considered worldwide. 

MALARIA is a disease mostly in tropical areas, where it is a major medical problem. Malaria is caused by a parasitic protozoa of the genus Plasmodium and is transferred when an infected female mosquito of the genus Anopheles bites a person and Plasmodium sporozoites enter the blood, where they first reach the liver and develop into merozoites over a period of 5-7 days without giving any symptoms. Then the immature merozoites penetrate the red blood corpuscles, where they divide asexually to form merozoites. When this process is complete, the blood corpuscles rupture and the merozoites enter the blood plasma. The rupture of the erythrocyte membrane provokes a fever, which occurs every second day after infection with Plasmodium vivax, every third after infection with Plasmodium malaria after infection with the severe Plasmodium falciparum fever is more irregular, because the parasites of this species do not develop simultaneously. 

Hydroxychloroquine sulfate is a 4-aminoquinoline compound that interferes with parasitic nucleoprotein (DNA/ RNA) synthesis and parasite growth or causes lysis of parasite or infected erythrocytes. In rheumatoid arthritis, it may suppress formation of antigens responsible for symptom-producing hypersensitivity reactions. It is indicated for prophylaxis and treatment of acute attacks of malaria caused by Plasmodium vivax, Plasmodium malariae, and Plasmodium ovale, and susceptible strains of Plasmodium falciparum. It is also used for treatment of chronic discoid and systemic lupus erythematosus (SLE) and acute or chronic rheumatoid arthritis in patients not responding to other therapies. 

Malaria is caused by protozoan parasites of the genus Plasmodium, four species of which infect humans. P. falciparum, P. vivax, P. malariae, and P. ovale) (48,49). The disease is initiated when infective sporozoites are injected into the human host during feeding by an infected mosquito. The sporozoites enter parenchymal cells of the liver within minutes where they multiply asexually into merozoites. After development for 6-16 days, depending on the species, merozoites are released from the hepatic cells into the peripheral blood where they quickly bind to and invade erythrocytes. This initiates the cycle of erythrocytic schizogony in... 

Clinical malaria is characterised by periodic fever, which follows the lysis of infected erythrocytes, and caused mainly by the induction of cytokines interleukin-1 and tumour necrosis factor. P. falciparum infection can have serious effects, for example anaemia, cerebral complications (from coma to convulsions), hypoglycaemia and glomerulonephritis. The disease is most serious in the non-immune, including children, pregnant women and tourists. Humans in endemic areas, who have survived an attack of malaria, are semi-immune and disease can be characterised by headache and mild fever. Infection by the other species of Plasmodium is normally self-limiting although relapses may occur, particularly in P. vivax infections. The species of parasite and the age and immune status of the patient are important in considerations of treatment and interpretation of the effects of all medicines. 

Plasmodium vivax (benign tertian) is the most prevaient form of malaria. It has an incubation period of 1 to 4 weeks (average, 2 weeks). This form of maiaria can cause spleen rupture and anemia. Reiapses (renewed manifestations of erythrocytic infection) can occur. This results from the periodic reiease of dormant parasites (hypnozoites) from the iiver cells. The erythrocytic forms generaiiy are considered to be susceptibie to treatment. 

Malaria A protozoan disease caused in humans by four species of the genus Plasmodium (P. falcipamm (malaria, falciparum), P. vivax (malaria, vivax), P. ovale, and P. malariae) and transmitted by the bite of an infected female mosquito of the genus Anopheles. Malaria is endemic in parts of Asia, Africa, Central and South America, Oceania, and certain Caribbean islands. It is characterized by extreme exhaustion associated with paroxysms of high fever, sweating, shaking chiUs, and anemia. Malaria in animals is caused by other species of plasmodia. [nih]... 

The variety of malaria parasites is almost as confusing as their nomenclature since the first observation of the living parasite by Laveran in 1880, there have been described over 100 different types, and the number of anopheline vectors is of the same order. Fortunately, only four plasmodial species infect man, namely Plasmodium falciparum, P. malariae, P. ovale and P. vivax, but numerous others parasitise various species of mammals. 

Plasmodium vivax, the cause of benign tertian malaria, produces milder clinical attacks than those of P. falciparum, and death is uncommon even in untreated cases. The build-up of immunity in the host rapidly controls the infection and schizonts disappear from the blood stream. The exo-erythro-cytic forms in the liver, unaffected by immunity, continue asexual division and reinvade the circulation when immunity has fallen once more these relapses are characteristic of vivax malaria and occur for at least two years after the primary infection. Infections due to P. ovale also follow a tertian pattern, but are much milder and more responsive to therapy than those due to P. vivax and relapses are less frequent. Infections due to both these parasites often display a prolonged incubation period between the primary infection and the development of malarial symptoms. P. vivax is widely distributed north and south of the equator, extending from the tropics to the temperate zones, while P. ovale is restricted to tropical Africa and the western Pacific. 

Douglas and coworkers [171] have strongly recommended artemisinin-based combination therapies to eliminate malaria, which is used to treat P. falciparum malaria even when most blood-stage infections caused by Plasmodium vivax still respond to chloroquine treatment, a chloroquine-resistant P. vivax strain has been already detected, suggesting that artemisinin-based combination therapies should be used to treat both parasite strains. 

However, the earliest written documentation on malaria can be found in the legendary Canon of Medicine , TheYellow Emperor s Inner Classic (Huangdi Neijing), dating from 2698 to 2598 BC. This book describes epidemics, characterised by febrile paroxysms (fever attacks occurring in flushes) in conjunction with enlarged spleen, which can be interpreted as Plasmodium vivax- or Plasmodium malariae-infections (Fig. 5.165). [416, 417]... 

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