Semmelweis urges handwashing

Hungarian doctor Ignaz Semmelweis found that deaths among new mothers fell sharply when doctors washed their hands with a chlorine solution. His ideas were rejected at the time.

Context

Semmelweis worked at the Vienna General Hospital, which had two maternity clinics. Mothers in the clinic staffed by doctors and medical students died of childbed fever far more often than those in the clinic staffed by midwives. He noticed that the doctors also performed autopsies, and he suspected that they carried something from the corpses to the patients.

In May 1847 he required staff to wash their hands in a chlorinated lime solution before examining patients. Recorded death rates in the doctors' clinic then fell sharply, from well above ten percent in some months to a few percent. The exact figures differ by source and period, but the direction of the change is well documented.

His explanation was rejected by many contemporaries, partly because germ theory had not yet been established and partly because his findings implied that doctors were causing deaths. He published his main work only in 1861 and died in 1865. Later work by Pasteur, Lister and others supported the principle that hygiene prevents infection, and he is now widely regarded as an early pioneer of infection control.

Modern hospitals rely on hand hygiene as a basic infection-prevention measure, and public health agencies today promote it for exactly this reason.