The first well-documented hospital infection outbreak is puerperal fever in the university hospital in Vienna. A Hungarian physician, Semmelweis gathered and analyzed mortality data with the help of his friend. His investigation led to handwashing intervention, which resulted in dramatic declines in maternal mortality rates. Recognition of his contribution to the history of epidemiology came long after his deaths mainly because of his poor writing and social skills.

Modern day epidemiology of hospital infections began in 1950s when epidemic of Staphylococcus aureus infections affected hospitals all over the world. Epidemiologic research was initiated to describe and understand hospital infections.

In the late 1970s, CDC conducted the landmark study, SENIC project, which I will introduce later.

In the 1990, hospital infections became one of the major focus of research in order to reduce the length of stay.