How did Agostino Bassi's research help prepare the way for germ theory?

Agostino Bassi was a foundational figure in public health and medicine whose work significantly anticipated the germ theory of disease.1

Through 25 years of research into mal de segno, a disease affecting silkworms, Bassi demonstrated that the condition was contagious and caused by a microscopic, parasitic fungus. By identifying that this organism was transmitted through contact and infected food, he established a clear causal link between a specific microorganism and a specific disease.1

Bassi’s most critical contribution to the development of germ theory was his bold generalization that many diseases in plants, animals, and humans are caused by such parasites. By formulating this principle, he preceded later pioneers like Louis Pasteur and Robert Koch by over a decade. His research provided an early, essential framework for understanding infectious transmission, which eventually led to modern medical practices such as sterilization and advanced infection control.12