Germ theory denialism (GTD) is as old as germ theory itself beginning with the rivalry of Pasteur and Béchamp. Pasteur's work in preventing beverage contamination led him to discover that it was due to microorganisms and led him down the path to be the first scientist to show the theory was valid and popularize it in Europe.[2] Although he was not the first to have the idea and scientists such as Girolamo Fracastoro (had the idea that fomites could harbor the seeds of contagion), Agostino Bassi (discovered the muscardine disease of silkworms was caused by a fungus that was named Beauveria bassiana), Friedrich Henle (developed the concepts of contagium vivum and contagium animatum), and others had earlier proposed ideas similar to germ theory.[4][5]