Life

Protista as disease-carriers

Protista live anywhere, provided there is even a little amount of water.
There are marine and freshwater species that live both floating on the water or on the seabed. A small water pond is enough for these micro-organisms to live; they can usually be found even in the thin film of water that covers the soil particles. Finally, there are many parasitic species, some of which transmit serious diseases to man. Here are some of the most important diseases that affect man:
• the sleeping sickness caused by trypanosomes, such as, for instance, the Tripanosoma gambiense, transmitted to man by some species of the tsetse fly
• toxoplasmosis, a disease affecting nearly 50% of the human population; harmless in itself, it becomes dangerous when it affects a pregnant woman since it is transmitted to the child, causing deformities
• malaria, transmitted to man by the anopheles, parasited by the Plasmodium. This disease still causes approximately 3 million victims a year, of whom one million are African children.