What is the one of the Most Important Medical Discoveries all time?

Article: What do you think is probably one of the most important medical discoveries of all time? Believe it or not, it was the discovery of using soap and water! Here's the story. In 1946, no one knew anything about germs or what caused illnesses to spread. A Hungarian doctor Ignaz Semmelweis (possibly Jewish), wanted to study why women in the hospital having babies kept dying from a type of fever (puerperal fever). In one clinic, women were treated only by male doctors, in another clinic, only by female midwives. When he compared the data of women from each clinic, he found that the women staffed by the doctors died nearly 5x more than those in the midwife ward. Why?

He looked for the difference between the two clinics. In the doctors' clinic, women only had babies while lying on their backs. But when Dr. Semmelweis asked them to move positions, it didn't change the death rates. Then he found that in the doctors' ward, priests would walk by ringing bells. But when he asked the priests to stop doing that, it also didn't change the death results. Then a doctor became ill with the fever. This caused Semmelweis to realize that the fever wasn't something unique to the women. So Semmelweis guessed something else. The doctors were holding the bodies of women who died, then they would help deliver babies. So something on the doctors' hands was passing back and forth between the women who had died from fever and women who were still alive. Maybe this is what was causing the fever to be passed around. So he ordered the doctors to all start cleaning their hands and instruments not just with soap but with chlorine (now known as the best disinfectant in the world). And women stopped dying!

Semmelweis discovered that hand-washing is one of the most important tools to keeping people healthy. It can keep people from getting the flu, prevent the spread of disease and keep infections away.

Sadly for Semmelweis, it didn't end happily. The doctors were angry that Semmelweis made it look like they were spreading the disease. They made him lose his job and he eventually died in a hospital with a disease likely caused from getting infected by someone who didn't wash hands!