By: Courtney Southwick
This past summer, my husband and I took a trip to England to celebrate our anniversary and my graduation from my master's program. Being a health science major, I was excited to see the Broad Street pump in London. In fact, that was our first stop after we flew into Heathrow!
We drove through the awful London traffic to see the pump. That spot is very exciting to me because it is the birthplace of the field of epidemiology. It’s the spot where in 1854 a physician named John Snow tracked down the source of a cholera epidemic and changed the future of medical science.
Cholera was very common in London at the time. It is an acute diarrheal illness caused by the Vibrio cholerae bacterium. It is spread through the fecal-oral route, meaning people become infected by ingesting contaminated food or water. The symptoms can be severe: watery diarrhea, vomiting, rapid heart rate, and extreme dehydration of the body. The loss of fluid happens so quickly that death usually comes within a few hours.
There were cholera epidemics every few years in 19th-century London and each time, thousands died. The idea that germs caused disease was very new and not widely accepted during this time. Microscopes were also very uncommon so there was no way to see the cholera bacterium. London’s poor sanitation and open slaughterhouses created a putrid smell in the air. At the time, most people assumed that the bad air, or miasma, was the cause of disease.
Dr. John Snow was the only person who suspected that cholera came from the water supply. Most Londoners got their water from community street pumps. Dr. Snow interviewed survivors and found that their symptoms always started in the gastrointestinal tract. He thought that if it was caused by miasma, the symptoms would be pulmonary.
He published a paper blaming it on the water, and no one took him seriously. The idea of invisible microbes infecting water and causing sickness was an outrageous idea for its time.
During a particularly bad outbreak in Westminster, Dr. Snow went door to door interviewing hundreds of family members of cholera victims. Almost all of them said the victim had gotten their water from the Broad Street Pump. He felt that this confirmed his theory and asked the Board of Guardians to remove the pump’s handle. The Board did not take him seriously. It took a lot of convincing, but eventually they agreed to remove the handle, just in case he was right.
The intervention worked. Soon after the pump was disabled, cases of cholera decreased dramatically.
Dr. John Snow revolutionized medical science. He was the first to track down the cause of an illness and produce a hypothesis for transmission of a disease. He was the first to systematically investigate cases and propose an intervention – removing the pump handle – which prevented further cases. None of this had ever been done before. He created the field of epidemiology and his work is still highly regarded today.
My husband and I visited the pump on a weekend evening in June. People were drinking inside the aptly named John Snow pub nearby and spilling out onto the sidewalk. At the pump, backpacks and jackets were piled up as people stood nearby drinking and chatting.
I began to take a few pictures when a group of men noticed and cleared the area of their belongings. They stared, curious as to why I was taking pictures of a defunct water pump. One man stopped me and asked, “Why do people keep taking pictures of this pump?”
Being a student of epidemiology, I struggled to keep my explanation short. As I told him the significance of the pump, his friends leaned in to listen. After my story, one of them said, “Wow, we’ve been coming here for years and had no idea!” Together, the group raised their cups of beer and cheered, “To John Snow!”
I've been writing since I was twelve years old, and I fell in love with science in the 9th grade. In addition, I was raised by a writer and a historian, so I am here to combine my love of science, history, and writing. Join me here as I blog about the history of science and medicine.