Malaria, caused by a sporozoan, is one of the most serious infectious diseases of recent history. Over 100 million people have malaria at any one time, and over a million, mostly children, die from it every year. Victims die of anemia, kidney failure, or brain damage unless the disease is brought under control by the person's immune system or by medical treatment. When an Anopheles mosquito "bites" a human to obtain blood, it injects saliva mixed with a substance that prevents the blood from clotting. If the mosquito is infected with Plasmodium (malaria), it will also inject about 1,000 elongated cells of this protist into the bloodstream of its victim.
There are three stages: The stage where it lives in mosquitoes and is injected into humans is called the sporozite. …
