You Know Nothing Jon Snow, but You Know a lot John Snow
If you are a Game of Thrones fan and expecting a Plastic Surgeon’s perspective of the protagonist Jon Snow — I’m sorry to disappoint. The following blog discusses the legacy of John Snow, the Father of Modern Epidemiology.
In 1854, a Cholera outbreak occurred in Soho, London. The English physician and surgeon, John Snow, was experienced in the treatment of Cholera having treated many such patients and researching the disease at the Newcastle Infirmary.
Snow developed detailed maps of the cholera outbreak and successfully tracked and charted the outbreak to households clustered around the Broad Street water pump. It is said that Snow created his maps of the disease outbreak using a network of street urchins who helped identify which households were affected by Cholera which is evocative of the Baker Street Runners in Sir Arthur Conan Doyle’s fictional writings on the adventures of Sherlock Holmes (Conan Doyle himself was a physician).
The dot maps created by Snow combined with statistical analysis led to the conclusion that polluted water was the source of the 1854 Cholera outbreak in Soho. What is remarkable about this analysis is that it occurred before the Germ Theory of disease transmission was widely accepted in the medical field. That is to say that at the time, there was no means of actually detecting the cholera bacteria/pathogen in the water whether by inspection under a microscope or by chemical assay.
Snow’s analysis concluded that households that drew their water from a pump supplied from the Thames River were 14-times more likely to be infected with cholera compared with households in the same neighborhoods that were supplied by cleaner water up-river. Within the same neighborhood, a brewery experienced no cases of cholera during the outbreak as the workers drank beer and seldom water. John Snow described his observations as follows:
“With regard to the deaths occurring in the locality belonging to the pump, there were 61 instances in which I was informed that the deceased persons used to drink the pump water from Broad Street, either constantly or occasionally…
The result of the inquiry, then, is, that there has been no particular outbreak or prevalence of cholera in this part of London except among the persons who were in the habit of drinking the water of the above-mentioned pump well.”
Snow, J. On the Mode of Communication of Cholera, 8vo, London; 2nd ed. 1855.
John Snow’s analysis led to the decommissioning of the Broad Street pump by famously removing the handle of the pump. Visitors to London may still see the Broad Street Pump sans handle which is preserved as a brass sculpture.
John Snow’s work ushered in a new era of medicine and Public Health, and he is recognized as the Father of Modern Epidemiology. Fast forward 170-years and we are now confronted with a global pandemic. While modern medicine has made astonishing progress in the fields of diagnosis, data acquisition, big data analysis, and treatments, John Snow’s original concepts are just as relevant as when they were first discovered in 1854. Identification and isolation of early outbreaks clearly are the earliest and best steps to preventing an epidemic. Global data tracking and objective analysis must guide Public Health Policy in disease mitigation until an effective treatment or vaccine is invented. Since this is a global problem, cooperation between governments is essential.
While debates and mixed messages regarding social distancing and masks continue to swirl in a politically divisive atmosphere, I would simply offer the following perspective: it is clear that droplet transmission is the equivalent of the Cholera tainted waters of 19th century London and social distancing, safe bubbles and respiratory barriers (masks) are the modern day equivalent of removing the handle of the Broad Street Pump.
Dr. Reddy is a Board Certified Plastic & Reconstructive Surgeon and a Fellow of the American College of Surgeons and a Clinical Assistant Professor of Bioengineering at Georgia Tech. He spent much of his training and career in tertiary care hospitals where he served on Infection Control Committees. During his General Surgery training, he studied and presented strategies to reduce Central Line Infections in Critically ill patients.
P. Pravin Reddy, MD is a Board Certified Plastic & Reconstructive Surgeon and a member of the American Society of Plastic Surgeons.