Charles Louis Alphonse Laveran (1845-1922) was a French physician. In 1880, after observing the parasites in a blood smear taken from a patient who had just died of malaria, he discovered that the cause of malaria is a protozoan. This was the first time that protozoa were shown to be a cause of disease. He later worked on the trypanosomes, particularly sleeping sickness. For this work and later discoveries of protozoan diseases he was awarded the 1907 Nobel Prize for Physiology or Medicine. He lived to be 76 and died of natural causes.