The 19th-century Hungarian physician Ignaz Semmelweis (pictured) noticed a marked difference in the rate of child-bed fever in two of the wards at the Viennese hospital where he worked. One was staffed by nurses, the other by students - some of the latter straight from the dissecting rooms.
When he asked staff to start washing their hands, the infection rate fell seven-fold. But Semmelweis's views were not popular, and he was more or less kicked out.
Alas, this hard-won lesson is being neglected. In the Journal of the Royal Society of Medicine (94: 278-281) Dr Sheldon Stone, from the department of geriatric medicine at London's Royal Free Hospital, points out that one in every 11 of today's inpatients acquires a hospital infection and that the extra cost to the NHS is£3,000 a time - an annual bill of nearly£1bn.
As many as a third of these episodes are thought to be preventable. And one of the simplest and most effective strategies is. . . hand-washing.
The wondrously titled Hand Hygiene Liaison Group has dug out nine controlled studies of hand-washing, all showing significant reductions in infection. As Dr Stone comments, 'The treatment effect is so great that if 'hand-hygiene' were a new drug it would be used by all.'
Under the NHS plan, chief executives are supposed to be personally accountable for hospital-acquired infection. So here's my tip for keen managers with a reckless streak. Next time you meet one of your senior surgeons in the hospital corridor, stop him, greet him, shake his hand - and then ask him when he last washed it.