Plasmodiidae

Plasmodium malariae

• Haemoproteus
• Leucocytozoon
• Plasmodium
• Polychromophilus

Plasmodia ( Plasmodiidae ) are infested (Diptera ) single-celled parasites that mainly mammals ( Mammalia) and Diptera. Divided they are in the trunk of the Apicomplexa. In the family of plasmodia, there are four sub- families with up to 170 species, see also Plasmodium. The plasmodia are among the sporozoa.

Features

Plasmodia are unicellular organisms which lack a cell wall, but as eukaryotes, in contrast to bacteria and archea ( prokaryotes ) have a nucleus. You are comma-shaped and quite slim, because of their lifestyle they take depending on the host and stage of development different shape. The smallest form, the trophozoite, measures three microns, the largest form of Leberschizont up to 70 microns.

Heterozygous carriers of sickle cell anemia, a plasmodium infection proceeds much weaker than in healthy individuals. In areas where malaria ( a disease caused by plasmodium ) is widespread, carriers are this hereditary disease (selection ) advantage. Therefore, the percentage of heterozygous carriers in the population in these areas is significantly higher than in malaria - free regions.

Dissemination

Plasmodia are now found mainly in tropical and subtropical areas; because their development is strongly dependent on the temperature, plasmodia are even there only available up to an altitude of less than 1500 meters. Until the 19th century they were also common in Northern Europe, but were wiped out by river regulation and swamp reclamation. It can still be found remainders in the Central Asian space: Armenia, Georgia, Kazakhstan, Kyrgyzstan, Tajikistan, Turkey, Turkmenistan and Uzbekistan.

Life cycle

As a final host are mosquitoes, particularly of the genus Anopheles; the multiplication of Plasmodium takes place in them, the man serves as an intermediate host. There are four species of Plasmodium that cause malaria in humans; they belong to the genus Plasmodium. After the man was bitten by an infected Anopheles mosquito, it secretes with their saliva, which contains anticoagulants, sporozoites. These are carried by the bloodstream to the liver where they invade the cells of the liver tissue and mature in the Leberschizont. There, their multiplication takes place, which is called " exoerythrozytäre schizogony "; arise up to 30,000 merozoites. Plasmodium vivax and Plasmodium ovale lay between these stages, a period of rest; thereby remain undivided Hypnozoiten in liver tissue and thus provide after months of re-infection, even if the initial infection has been overcome. The merozoites pass into the bloodstream and infect red blood cells then. They penetrate into this and begin to intracellular share. From this division are shown eight to sixteen new merozoites. The four humans infesting plasmodia following division times have been observed:

After the division of the residuals are absorbed by hemoglobin free merozoites, the hemozoin, this solves the fevers of malaria from typical. After a few days to weeks of production of merozoites begin some to mature cells ( gametocytes ) to mature. These can now be found together with the merozoites in the blood ( see also: Generation change).

Through attacks of fever and the accompanying sweating infected carriers are again attractive to mosquitoes because they have a good smell and temperature sense. With a new stitch these gametocytes are taken up by the mosquito, where they unite to form a Wanderzygote. These show the ookinete, which anneals between the tissue layers of the mosquito stomach and there is the oocyst; in her create up to 1,000 new sporozoites. From there, they migrate to the salivary glands of the mosquito and are ready to re-infection of an intermediate host, such as humans.