Plasmodium: Intriguing Beginnings
Plasmodium, the malaria-causing parasite, has a complex life cycle starting in the Anopheles mosquito. Female mosquitoes transmit the parasite through their saliva during a blood meal.
Human Host Invasion
When humans are bitten, sporozoites enter the bloodstream, traveling to the liver. There, they infect hepatocytes, multiplying asexually, unseen by the immune system.
Merozoite Multiplication Stage
Sporozoites transform into merozoites inside hepatocytes. These rupture liver cells, re-enter the bloodstream, and then invade red blood cells, leading to clinical symptoms.
Asexual Reproduction Cycle
Within red blood cells, merozoites mature to trophozoites and schizonts, which rupture the cell, releasing new merozoites. This cyclical destruction causes anemia and periodic fevers.
Sexual Phase Initiation
Some merozoites develop into gametocytes, the sexual form of the parasite, which must be taken up by another mosquito to continue the cycle.
Mosquito: The Breeding Ground
In the mosquito's gut, gametocytes mature, mate, and form oocysts. These burst, releasing sporozoites that migrate to the salivary glands, ready to infect a new host.
Cycle Complexity and Implications
Plasmodium's life cycle complexity includes evasion strategies like antigenic variation, challenging vaccine development and contributing to the parasite's resilience.
Where does Plasmodium start its cycle?
Human bloodstream
Anopheles mosquito
Red blood cells
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