A new era in the history of cholera: the road to elimination

One hundred and fifty years ago, Snow made the historic discovery that contaminated water transmitted cholera, but there were many other key discoveries and notable developments in the history of cholera. Koch cultured V. cholerae, the bacterium about which Snow could only speculate,1 and S.N. De discovered the enterotoxin produced by the bacterium resulting in massive outpouring of fluid.2 But these discoveries, by themselves, did not save the lives of cholera’s victims; 50% of them died until intravenous hydration therapy began to be used by Rogers in the early 1900s.3 This hypertonic intravenous solution reduced the case fatality rate, but not until the late 1950s and early 1960s were consistently successful treatments implemented based on careful intake and output balance studies.4,5 An especially important innovation, often taken for granted today, was the development of the ‘Watten cot’ which is now used routinely in cholera treatment centres worldwide.5 Watten first conceived this simple army cot with a hole in the middle onto which a cholera patient was placed. A plastic sheet funnelled the watery stool through the hole into a bucket under the bed, allowing for accurate measurement of stool output. Studies in Bangkok, Calcutta and Dacca used this cot to determine the volumes and chemical composition of cholera stools and ushered in a change in the basic concept about the treatment of cholera: the diarrhoea fluid that is expelled must be replaced by rehydration fluids in volumes and chemical composition to match that being lost. The Watten cot, originally used for these physiological balance studies, is now the standard of care and is used throughout the world for millions of patients with severe diarrhoea.