What is Malaria?
Malaria is a mosquito-borne disease that causes over 2.7 million deaths per year according to estimates by the World Health Organization. Scientists in the Life Sciences Division and the Center for X-Ray Optics (CXRO) at Lawrence Berkeley National Laboratory are working with the newly developed x-ray microscope at the Advanced Light Source to study this disease.
Mosquito-Borne Disease of the Blood
is a potentially fatal blood disease caused by a parasite that is transmitted
to human and animal hosts by the Anopheles mosquito. The human
parasite, Plasmodium falciparum, is dangerous not only be cause
it digests the red blood cell's hemoglobin, but also because it changes
the adhesive properties of the cell it inhabits. This change in turn
causes the cell to stick to the walls of blood vessels. It becomes especially
dangerous when the infected blood cells stick to the capillaries in
the brain, obstructing blood flow, a condition called cerebral malaria.
Scientists using the x-ray microscope are hoping to learn more about
the how the parasite infects and disrupts the blood cells and the blood
vessels of an infected host.
The Life Cycle of the Malaria Parasite
The life cycle of the malaria parasite in a human or animal begins when an infected mosquito transmits malaria sporozoites to a new host. The sporozoites travel to the liver, where they invade hepatocytes (liver cells) and multiply thousands of times over the following two weeks before rupturing out of the liver into the blood stream. During the first 48 hours after infecting a red blood cell, a parasite goes through several phases of development . The first phase is the ring stage, in which the parasite begins to metabolize hemoglobin. The next phase is the trophozoite stage, during which the parasite metabolizes most of the hemoglobin, gets larger, and prepares to reproduce more parasites. Finally, the parasite divides asexually to form a multinucleated schizont. At the end of the cycle, the red blood cell bursts open and the parasites are dispersed to infect more red blood cells.
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updated August 10, 2001