Malaria: Human Host | HHMI BioInteractive Video

The Lifecycle of the Malaria Parasite

Introduction to Malaria

• The malaria parasite is an ancient organism, predating human existence and has affected historical figures like Alexander the Great, Genghis Khan, and George Washington.

• The lifecycle of malaria involves a complex interaction between mosquitoes and humans, highlighting its adaptability.

Infection Process

• A pregnant mosquito seeks human blood, injecting saliva that prevents clotting while also delivering the malaria parasite into the bloodstream.

• The parasite travels through the bloodstream towards the liver, which serves as a critical target in its lifecycle.

Liver Infection

• Upon reaching the liver, the parasite infects liver cells by targeting Kupffer cells as entry points, leading to cell death during this process.

• Over several days, infected liver cells undergo numerous nuclear divisions to replicate their DNA extensively.

Red Blood Cell Targeting

• An infected liver cell can produce thousands of new parasites that are then modified to invade red blood cells for further survival.

• Inside red blood cells, parasites evade immune detection while consuming cellular contents and generating more parasites.

Consequences of Malaria Infection

• Infected red blood cells become sticky and adhere to blood vessel walls; once mature, they burst to release additional parasites into circulation.

• Symptoms of malaria include fever, loss of blood, convulsions, brain damage, and coma; it is estimated that 10% of people globally will contract malaria this year.