Final answer:
Girolamo Fracastoro first described the term "seeds of contagion" in 1546, referring to germ-like entities transferring diseases between individuals. His ideas were a precursor to the germ theory of disease, which was not widely accepted until substantial evidence and technological advances in the 19th century.
Step-by-step explanation:
The term "seeds of contagion" was first described by Girolamo Fracastoro, an Italian physician, in his essay De Contagione et Contagiosis Morbis, published in 1546. Fracastoro proposed the revolutionary concept that diseases could spread through seed-like spores, or germs, which were transferred by direct contact, through the air, or by contaminated objects such as clothing. This early form of the germ theory of disease laid the groundwork for our modern understanding of infectious diseases and how they are transmitted, though it would take centuries for this idea to become widely accepted.
Fracastoro's theory wasn't given much importance during his time due to the dominant miasma theory and lack of evidence, as the technology to observe microorganisms did not exist yet. It wasn't until the 19th century that with the advancements in microscope technology and findings of researchers like Anton van Leeuwenhoek, John Snow, and Louis Pasteur, the germ theory gained traction, profoundly changing the field of medicine and epidemiology.