Cholera, John Snow and the 2013 bicentennial meetings at the London School of Hygiene and Tropical Medicine, UK

The only thing new about the cholera epidemic that struck Haiti in October 2010, nine months after the devasting earthquake in January the same year, was that it was the first in the country’s recorded history. It turned out to be the world’s largest epidemic in recent decades, with the half a million suspected cases and over 7000 deaths reported by the Haitian government from mid-October 2010 to January 2012 probably an underestimate. Initially suspected by some scientists to be due to climatic changes, recent evidence points more conclusively to human activity. UN peacekeeping troops were deployed into Haiti in 2010 from Nepal where there had just been an outbreak of cholera. A few days after they arrived, cases of cholera appeared in the village next to their camp. It was known that waste pipes from the camp and from a septic pit allowed waste fluids to seep into a nearby river. Subsequently whole genome sequencing has indicated a close relationship between the Haitian and Nepalese epidemic Vibrio cholerae strains. Whereas interpretation of this evidence has provoked debate, what is indisputable is the similarity to the outbreak in London in 1854 which was eventually traced back to the seepage of waste fluid from a cesspit into the water supplied by the Broad Street pump. John Snow, through meticulous observation and record taking, had already worked out that the source of the epidemic was faecal contamination of water from the pump before this discovery was made, and had persuaded the Board of Guardians for the Parish to remove the handle of the pump. Snow’s painstaking and dedicated work, in the teeth of fierce opposition from those wedded to the then dominant miasma theory that cholera was caused by foul air, earned him posthumous recognition as the father of modern epidemiology. John Snow was born, the eldest of nine children, into a labourer’s family in York on the 15 March 1813 (Figure 1). For the whole of 2013 we will have a series of reprints related at least tangentially to Snow and cholera, which we hope will provide background to the genesis, dissemination, debate and legacy of his work. Examples will be from art, literature and engineering. Chaunt of the Cholera (selected verses) John Banim (1798–1842 Ireland)