Giovanni Battista Grassi (1854-1925): a forgotten Italian scholar and his fundamental studies on malaria.

A century ago, on May 4, 1925, an Italian doctor, zoologist, botanist, and entomologist Giovanni Battista Grassi (1854-1925) died in Rome. He was known for his studies on malaria, and he was one of the founders of the "Italian school of malariology". At that time malaria was a main problem in the colonies for the military and in the tropics is a common disease that causes high fever and other symptoms. When the French chemist Louis Pasteur published his germ theory in the 1860s, scientists began to consider that an organism, might be responsible for the malaria disease and the breakthrough came in 1880 with Alphonse Laveran (1845-1922). It was therefore clear that many diseases are caused by microorganisms, and several scholars began to assume that also malaria was caused by a bacterium. Laveran recognized the parasite group that caused the infection in human beings; however, his studies were challenged. In 1889 Laveran showed that malaria is caused by another type of single-celled organism, a protozoan of the Plasmodium family, which attacks red blood cells and also identified other single-celled parasites that cause other diseases: there are four main types of malarial infection caused by four species of parasite plasmodium. In 1898 Grassi began a study that represented a turning point in the study and treatment of the disease. The authors aim to retrace the main steps in the historical evolution of this dangerous, infectious disease and they believe it's important to evoke the scientific personality of the Italian scientist Grassi who is one of the protagonists in the history of medicine and zoology between the 19th and 20th centuries, mainly because of his famous research, about the identification of the vector of human malaria.