“The most terrible outbreak of cholera which ever occurred in this kingdom is probably that which took place in Broad Street, Golden Square, and the adjoining streets, a few weeks ago.”—John Snow, London, 1854
Cholera inspired terror in past centuries not just because the disease could erupt without warning, but because healthy people could be alive one day and dead the next. It was such a day just 150 years ago (30 August 1854) when 8 people in a London neighborhood were struck dead by raging diarrhea. The next day, 56 more were dead, followed by 153 the next. A prominent London physician named John Snow immediately went to work—not to treat the afflicted, but to consider their distribution. Within short order, Snow had identified a water pump on Broad Street as the likely route of the outbreak. Snow presented his data to public officials and, on Friday, the 8th of September, they removed the pump handle.
In this issue of Epidemiology, we celebrate the anniversary of this iconic event. Nigel Paneth, a coauthor of the recent Snow biography,1 reflects on Snow's work from a 21st century perspective. Ken Rothman conjures an interview with Snow to explore the man behind the maps. Scattered throughout our pages you will find quotes from Snow.
However, back to the Broad Street pump. Why does this particular event have such a grip on our imaginations? Perhaps it is because it so successfully captures our dual goals: the discoveries of disease etiology and disease prevention. The decisive role of the pump handle (in myth, if not in reality) bolsters us when our own work is anything but decisive. We grapple with subtle exposures, with latencies that span decades, with diseases of insidious onset and development. These uncertainties can lead us into gloomy introspection on the limits of our tools. However, these limits also encourage a culture in which we address the weaknesses of studies as openly as their strengths. Such candor is itself a strength, one not prominent in every area of science.
Our brilliant predecessors would probably be taken aback by the scope of epidemiology today. Still, one thing that has not changed is the spirit of critique and debate that characterizes the field. This, at least, John Snow would recognize. Were he alive today, he would no doubt be in the thick of the fray.
1. Vinten-Johansen P, Brody H, Paneth N, et al. Cholera, Chloroform, and the Science of Medicine: A Life of John Snow
. New York: Oxford University Press; 2003.