I've been looking into hospital hygiene for a freelance article I'm working on, and this article from the Times magazine had a doozy of a historical anecdote on the topic. After reading it, I felt the need to wash my hands a couple million times, OCD-style:
While it is now well established that germs cause illness, this wasn't always known to be true. In 1847, the Hungarian physician Ignaz Semmelweis was working in a Viennese maternity hospital with two separate clinics. In one clinic, babies were delivered by physicians; in the other, by midwives. The mortality rate in the doctors' clinic was nearly triple the rate in the midwives' clinic. Why the huge discrepancy? The doctors, it turned out, often came to deliveries straight from the autopsy ward, promptly infecting mother and child with whatever germs their most recent cadaver happened to carry. Once Semmelweis had these doctors wash their hands with an antiseptic solution, the mortality rate plummeted.
The rest of the article has some equally gross modern-day stuff about how bacteria can thrive on just about any available surface. If you've ever skipped the sink after using a public restroom (we're talking to you, Britney), please go read it right now.