Malaria

(Movie)

Malaria (from Italian mal'aria "bad air") - including fever swamp fever or exchange - is a notifiable tropical disease, the unicellular parasites of the genus Plasmodium caused. The disease is in the tropics and subtropics by the bite of a female mosquito (mosquito) of the genus Anopheles. Outside of those areas solve occasionally by air travellers mosquitoes introduced the so-called "airport malaria". These are all people working in the immediate vicinity of airports at risk, such as airport staff or residents. Except for the transmission through blood transfusion and laboratory accidents is a human-to-human infection only occasionally from mother to the unborn child when the placenta (especially during the birth) is violated. The man, and the Anopheles mosquito, the only significant reservoir of human pathogens Plasmodium dar.

In the genus Plasmodium, only the four pathogen Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale and Plasmodium malariae dangerous for humans (humanpathogen). Regarding their disease and their geographical distribution, they differ significantly. Plasmodium falciparum is the most significant and clinically threatening pathogens.

The symptoms of malaria are high, to periodic recurrent fever, chills, complaints of the gastrointestinal tract and cramps. Especially in children, the disease rapidly to coma and death.

Epidemiology
Geographical distribution

The geographical distribution (see map) is similar to the distribution of suitable as a vector Anophelesarten, bearing in mind that the presence of the anopheles at low sea levels is limited, that is, under 2500 m at the equator and at 1500 m in the remaining areas of Earth. Due to the increasing global warming indicates polwärtsgerichteten dealing with the spread of the mosquito vectors further geographical spread of malaria. The risk in the endemic areas is very different, which, inter alia, seasonal and geographical reasons. In sub-Saharan Africa Plasmodium falciparum clearly prevails over all other Plasmodienarten.

It is striking that in the malaria areas sickle cell anemia, a genetic disease with characteristic deformation of the red blood cells (sickle), a relatively common. Winners of this hereditary disease have an innate resistance to malaria and thus an evolutionary advantage over those without corresponding gene mutation, the more likely to die from malaria. The exact cause of resistance has not been unequivocally shown (see malaria resistance). The advantage, however, is limited only to heterozygous carriers of the mutation; homozygous carriers are dying prematurely at the sickle cell anemia. In Africa, there are regions where almost a third of the population heterozygous for this characteristic. In the other regions of the world, this mutation barely existent, because of this selective advantage because of the lack of malaria is not given.

Annual incidence victims and

According to the Robert Koch Institute in Berlin die worldwide each year from 1.5 to 2.7 million people from malaria, about half of them are children under five years. 90% of sufferers are living on the African continent. The annual number of new cases is 300 to 500 million cases.

In Germany, approximately 900 patients reported, of which 3-8 are dying (0,3-0,9%). The majority of patients in African endemic been on the (approximately 87%).

Pathogenesis
The infected with Plasmodium, ripening and bursting red blood cells Merozoiten contact with the toxins (such as phospholipids) free, which turn to the release of cytokines. The cytokines are primarily for the fever and an increase observed reduction in blood glucose (hypoglycemia). The lactic acidosis associated with hypoglycemia is not only the effect of cytokines caused, but is also a result of the metabolism of the parasite. Likewise, it is at high number of parasites in the blood by resolution (lysis) of the red blood cells, removal of infected red blood cells in the spleen and damping of the eritropoezo in bone marrow by the cytokine (especially by the tumor necrosis factor-alpha) to a anemia.

In addition, there are between Plasmodium falciparum malaria and other pathogens important pathogenetic differences.

Plasmodium falciparum
In the red blood cells produced the Trophozoit proteins, such as PfEMP1 (infected Plasmodium falciparum erythrocyte membrane protein 1), which binds the infected blood cells in the endothelium of the blood vessels causes. The associated microcirculation disturbances at least partly explain the significantly heavier course of caused by Plasmodium falciparum malaria tropica.

The attachment of red blood cells in the endothelium, and the lack of ductility of the infected cells, leads to a relocation of the capillaries and leading to a disruption of oxygen and nutrient supply to the area. This has in the central nervous system, especially dramatic impact and the central frequent complications of malaria tropica result. Small children can coma in a life in ruins (cerebral malaria).

wikipedia