Plasmodium is a genus of intracellular parasitic protozoa that is usually known as malaria parasites. They are called digenetic parasites because they are obligatory parasites of insects (such as mosquitoes) and vertebrates.
To complete their life cycle, they require two separate hosts. They multiply in the liver and red cells of vertebrates, where they not only acquire sustenance but also cause damage to the tissues (thus creating illnesses).
The following Plasmodium species can cause malaria:
P. falciparum
P. ovale
P. malariae
P. vivax
P. knowlesi
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The name “malaria” is derived from two Italian words: “mal” (bad) and “aria” (air).
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A mosquito that has been infected with the parasite remains unaffected (nor does it die from malaria). This is because, unlike vertebrates, mosquitoes lack red blood cells, which are where the parasite develops and thrives.
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Researchers recently discovered that infecting female Anopheles stephensi resulted in a considerable decrease in the quantity of plasmodium in the mosquito’s midgut and salivary glands. As a result, this could be one of the most effective ways to combat the malaria parasite.
Plasmodium Life Cycle
Plasmodium parasites have a three-stage life cycle that consists of Gametocytes, Sporozoites, and Merozoites.
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Gametocytes (Stage 1)
An anopheles mosquito transmits microgametocytes, which are male gametocytes, and macrogametocytes, which are female gametocytes, during a blood meal. The mosquito’s gametocytes mature into sporozoites. After 15 to 18 days, male and female gametocytes mate inside the mosquito’s gut and produce a parasite called sporozoite.
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Sporozoites (Stage 2)
When an infected mosquito feeds on humans, the sporozoites enter the bloodstream via saliva. The sporozoites then mature into schizonts in the liver cells. Later, the sporozoites rupture, releasing merozoites.
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Merozoites (Stage 3)
During the next one or two weeks, each schizont multiplies to generate a variety of merozoites. Merozoites erupt from the lever and re-enter the bloodstream, killing red blood cells. Merozoites continue to reproduce and grow, destroying all blood cells in the process. Certain merozoites develop into gametocytes, which are then injected into the circulation by mosquitos, restarting the cycle. When red blood cells are damaged, merozoites release a toxin that causes bone-chilling chills and fever. Human malaria is characterised by severe colds, chills, and fever.
The Effects of Plasmodium on the Human Body
Plasmodium, as previously stated, requires a vector to infect its victims (humans). The protozoan enters the host through the mosquito’s proboscis, which is carried by a female Anopheles mosquito. When the parasite infects and grows in the host, it looks for red blood cells to infect.
This changes the RBCs’ characteristics, making them stiff and inelastic. This means that tainted RBCs are unable to pass through capillaries, the smallest blood vessels. As a result, circulation in vital organs including the brain and kidneys may get obstructed. If left untreated, the condition can progress to organ failure and death. Plasmodium falciparum malaria produces even more serious harm, as blood cells are extremely fragile and have a shorter lifespan
Conclusion
Plasmodium has evolved in lockstep with vertebrate evolution over the last 120 million years. As a result, the plasmodium has evolved through new hosts, followed by adaptation to those hosts, illustrating the plasmodium’s main evolutionary logic. Among the Plasmodium species isolated from chimps are P. gaboni, P. falciparum, P. ovale, and P. reichenowi. The gorillas are kept apart from the other animals. P. mexicanum and P. florid sense are reptile plasmodium parasites, whereas P. relictum and P. juxtanuclear are avian plasmodium parasites.