Above all, do no harm. But back then …

WASH YOUR HANDS

Ignaz Semmelweis was the 19th-century Hungarian doctor who in 1847 discovered the wonders of clean hands as a way to stop the spread of infection.

He worked at Vienna General Hospital’s maternity clinic in 1846, and became deeply unsettled by the high maternal mortality rate in one of the wards. In the ward staffed by physicians and medical students, between 13 per cent and 18 per cent of new mothers were dying of a mysterious illness known as the childbed fever. In the ward staffed by midwives, about two per cent of women died of it.

Semmelweis scrutinized everything from the climate to the crowds at each maternity clinic. The only obvious difference was the midwives.

The physicians, Semmelweis realized, had been dissecting infected cadavers during autopsies with their bare hands.

Then, with those same contaminated hands, they were delivering babies.

So he required anyone examining a woman in the labour room to wash their hands in a chlorinated lime solution before entering, especially those who just touched dead bodies. Within a matter of months, the maternal mortality rate dropped to match that in the midwives’ ward.

Dana Tulodziecki of Purdue University said it sounded radical to some. Back then, people believed in the “miasma theory,” that wafting toxic odours were responsible for spreading diseases through the air. If people washed their hands in earlier decades, she said, it was because they were trying to get rid of the smell, not the germs.