This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
For most of medical history, severe diarrheal disease killed by dehydration, and the only real treatment was an intravenous line, a resource few of the world's poorest patients could reach in time. That changed in the hospital wards of Dacca, in what is now Bangladesh, where physicians Richard Cash and David Nalin ran the trials that, in the late 1960s, proved a patient could be rehydrated by mouth instead of by needle: a carefully measured solution of glucose and salt, drunk rather than infused, could maintain a cholera patient's fluid balance as effectively as an intravenous line, at a fraction of the cost and without the trained staff a drip requires.
The British medical journal The Lancet has since called the discovery the most important medical advance of the twentieth century, and in 1978 the World Health Organization created its own diarrheal disease control program to carry the treatment to the clinics and camps that needed it most. The claim has aged well: researchers estimate that oral rehydration therapy has saved something like seventy million lives since its introduction in the late 1970s, at a cost, in lower-income countries, of around fifty cents a treatment course. Few medical advances in history have done as much good for as little money.