Dr Ignaz Semmelweis observed that the incidence of women dying after childbirth could be dramatically reduced by health workers washing their hands.
As a result of his hand disinfection initiative, “mortality rates in the first division dropped from 18.27 to 1.27 per cent, and in March and August of 1848 no woman died in childbirth in his division,”
-Encyclopaedia Britannica
He was mocked, dismissed from the hospital, harassed by the medical community, stressed to the point of nervous breakdown, tricked into being committed to an asylum, doused in cold water, force fed laxatives, beaten & as a result died from blood poisoning at only 49. 
History & science have vindicated him.
Thank you, Dr Semmelweis.
We are grateful.