Background Surgeon’s apprentice at the age of 14 Became a member of the Royal College of Surgeons in 1836 Graduated from the University of London in 1844 Accepted to the Royal College of Physicians in 1850

State of Medicine Major Advancements 1. Acceptance of the germ theory Infection caused by a living organism 2. Use of Anesthesia Allowed surgeons to be more percise Technological Innovations Thermometer Microscope Stethoscope

Cholera Bacterial disease of the intestine Causes victims to die of severe dehydration 50-60% mortality rate if untreated

Broad Street Cholera Outbreak Cholera led to thousands of deaths in Soho, a suburb of London, from 1831 to 1854 Within 250 yards of the Cambridge and Broad Street intersection upwards of 500 fatal attacks due to cholera were recorded in ten days

Urban Life World’s largest urban population of 2.5 million Only the most basic requirements for the disposal of human waste Drinking/washing water was obtained from town wells or communal pumps

Cause of Cholera Farr Breathing miasma, pollution, in from the atmosphere Possible causes of miasma: Plague pits- pits where those who died from the plague of 1665 were buried Improper disposal of human waste Snow Drinking of contaminated water Possible causes of contamination: Sewage dumping into water source Runoff from improper disposal of human waste Runoff from plague pits

Broad Street Pump A factory near the Broad Street pump kept two tubs of water from the pump on hand for employees to drink and 16 of the workers died from cholera A coffee shop that served glasses of water from the Broad Street pump with meals knew of nine customers who had contracted cholera A prison near Soho had 535 inmates with its own well and bought water from the Grand Junction Water Works had nearly no cases of cholera

Snow’s Research London began releasing more complex mortality reports a decade before the outbreak, which allowed Dr. Snow to find patterns related to cholera Examining the public records Snow saw that the majority of deaths occurred near the Broad Street pump Dr. Snow used a spot map to illustrate the location of the deaths in the Broad Street area He first exhibited this map at a meeting of the Epidemiological Society of London in December 1854

The Famous Map

Public Officials Reaction On September 7, 1854 the Broad Street pump handle was removed Upon removal cholera outbreaks almost stopped immediately Public officials still saw Snow’s hypothesis as “nonsense” The Board of Health said, “we see no reason to adopt this belief”

End of Cholera In 1883, German physician, Robert Koch isolated the bacterium Vibrio cholera Dr. Koch determined cholera was not contagious from person to person, but only spread through unsanitary water of food This evidence finally confirmed Dr. Snow’s theory In the 19 th century cholera epidemics in Europe and the U.S. stopped with improved water sanitation

Legacy “The Father of Epidemiology” In 2003 Hospital Doctor magazine named John Snow the “greatest doctor” of all time In 1993 The John Snow Society was founded In 2001 The John Snow College was founded