Plasmodium ovale infection

Chloroquine is a rapidly acting blood schizonti-cide with some gametocytocidal activity. It is used with primaquine for Plasmodium vivax and Plasmodium ovale infections. It has been widely used prophylactically by traveler s to endemic areas. Its mechanism of action is unclear. It is believed to hinder the metabolism of hemoglobin in the parasite. Presumably chloroquine prevents the formation in the plasmodia of polymers out of free heme which then builds up and becomes toxic. Resistance occurs as a consequence of the expression of a membrane phospho-glycoprotein pump in the plasmodia which is able to expel chloroquine from the parasite. Plasmodium falciparum is the most likely to become resistant. 

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. 

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 ... 

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. 

Four different protozoa of the genus Plasmodium -P. falciparum, P. vivax, P. ovale and P malariae - can cause malaria. P. falciparum is the most virulent, being responsible for virtually all fatal malaria cases. Humans are infected by a feeding female Anopheles mosquito (Fig. 2). The clinical symptoms of malaria are associated with the development of the parasite within human red blood cells, while the liver stages remain asymptomatic. The following dtugs (in alphabetical order) are currently in use for the treatment of malaria [5]. 

Malaria remains a major public health problem in many parts of the world, including Southeast Asia, sub-Saharan Africa and Latin America where an estimated 300-500 million people are infected. 1-3 million die of malaria every year. The etiologic agents of malaria are protozoan parasites of the genus Plasmodium. Of the four pathogens that can cause malaria in humans (Plasmodium falciparum, P. vivax, P. ovale,... 

Malaria is transmitted by the bites of the Anopheles mosquitoes which introduce into the bloodstream one of four species of sporozoites of the plasmodia (Plasmodium falciparum, P. ovale, P. vivax or P. malariae). Initial symptoms of malaria are nonspecific and may resemble influenza and include chills, headache, fatigue, muscle pain, rigors, and nausea. The onset of the symptoms is between 1 to 3 weeks following exposure. Fever may appear 2 to 3 days after initial symptoms and may follow a pattern and occur every 2 or 3 days (P. vivax, P. ovale and P. malariae). Fever with P. falciparum can be erratic and may not follow specific patterns. It is not unusual for patients to have concomitant infections with P. vivax and P. falciparum. Falciparum malaria must always be regarded as a life-threatening medical emergency. 

The malarial parasite is a single-cell protozoan (plas-modium). Although more than 100 species of plasmodia have been identified, only four are capable of infecting humans Plasmodium malariae, P. ovale, P. vivax, and P. falciparum) the rest attack a variety of animal hosts. P. falciparum and P. vivax malaria are the two most common forms. 

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. 

Over 100 Plasmodium species contribute to the spread of malaria, but only four of these (P. falciparum, P. vivax, P. ovale, and P. malariae) account for human infection, the deadliest being P. falciparum. The malaria life cycle exists first in a mosquito, and then it passes to a human host. An infected female Anopholes mosquito is the host of the parasite s sporogonic hfe cycle. Mature P. falciparum sporozoites reach the salivary glands of the mosquito, and the parasite is transmitted to a human host when the mosquito feeds. During this blood meal, sporozoites are released into the bloodstream where they penetrate hepatic cells and mature into schizonts. The liver cells rupture after approximately two weeks, discharging merozoites into the bloodstream whereupon they infect red blood cells (RBCs). Every 48 to 78 hours, mature merozoites rupture from... 

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 devastating human disease that causes more than 850 000 deaths each year. The disease is caused by a protozoan parasite of the genus Plasmodium, which is obligate intracellular protozoan parasites of humans and animals, and the symptoms of the disease are largely a consequence of the asexual multiplication of these parasites within erythrocytes in the host. The Human disease is caused by the Plasmodium species P. falciparum, P. vivax, P. ovale and P. malariae. The life cycle of the Malaria parasite is extremely complex involving distinct cellular morphologies for infection of the host organism (human or other animal) and the infectious vector, the mosquito... 

Malaria is a disease caused by Plasmodium protozoa and transmitted by of mosquito vectors (Anopheles spp.), bites [93] to men, monkeys, rodents, birds, and reptiles [94]. The main agents involved in human malaria fever are four species of Plasmodium protozoa (single-celled parasites) P. falciparum, P. vivax, P. ovale, and P. malarie. Among these, P. falciparum accounts for the majority of infections, and it is the most lethal one. 

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