The 16th century Italian monk, Fracastorius, recognized some ways infection can spread. His conclusion that disease could pass by intimate direct contact from one person to others, was easy because he saw the dramatic epidemic of syphilis that was so obviously spread by sexual intercourse. He described this in a mock heroic poem, Syphilis, sive morbis Gallicus (1530) about the swineherd Syphilis, and how he got and passed on to others the "French disease" then raging in Europe. His anti-hero, of course, gave us the name of the disease.

Fracastorius’s other concepts, droplet spread and spread by way of contaminated articles such as clothing and kitchen utensils, were published in De Contagione, in 1546. Fracastorius is important because he made a conceptual breakthrough, brought about what Thomas Kuhn calls a paradigm shift in understanding of infection and some ways to control it.

After Fracastorius the pathfinders on the road to health became so numerous I can mention only a handful of my personal public health heroes: John Graunt, James Lind, Edward Jenner, John Snow and Louis Pasteur.