London's Cholera Outbreak of 1854
The story of Dr. John Snow and the contaminated Broad Street pump.
The London of the mid 1800’s was quite different from the London of today. Large amounts of people had migrated to the city causing surges in the population that made keeping up with trash disposal and the management of human waste difficult. Infectious diseases, such as Cholera, were much more common at the time, due in part to conditions in the city but also to the lack of knowledge on how these diseases were transmitted. In 1854, however, one physician would forever change these misunderstandings and revolutionize the investigation of infectious disease outbreaks.
Dr. John Snow was a revolutionary of his time. As a young physician, he was a pioneer in his work on anesthetics and hygiene in medicine. He quickly took notice when a significant outbreak of Cholera appeared to be demonstrating peculiar patterns, being centralized around Broad Street in the London district of Soho. In 1854, it was popularly believed that certain infectious diseases, including cholera, were spread by the putrid air caused by inappropriately managed trash and excrement. John Snow’s investigation, however, would reveal that this putrid air, otherwise known at the time as miasma, was not at all the cause for this incredibly destructive outbreak, nor other infectious diseases.
John Snow set out to the streets of Soho, talking with residents in the district, especially those who were infected with the disease. He quickly surmised from his investigation that a contaminated water source was in fact responsible for the outbreak in Soho, specifically, the Broad Street water pump. Unfortunately, Dr. Snow was initially met with resistance as he tried to convince his colleagues and those in power of this novel mode of transmission. Many were still convinced that miasma was the cause of the disease and subsequently of the outbreak. Eventually, the city conceded to his theories and had the handle of the Broad Street pump removed. Almost immediately, the district saw a rapid decline in Cholera cases, leading to the end of the 1854 outbreak. Researchers would later come to learn that the pump had been dug within 3 feet from an old cesspit which had begun to leak fecal matter, thus contaminating the water and inciting the outbreak.
If you’re interested in learning more about John Snow and his contribution to infectious disease epidemiology, I would highly recommend the book “The Ghost Map: The Story of London’s Most Terrifying Epidemic — and How it Changed Science, Cities, and the Modern World.” by Steven Johnson