Transmission Time Machine: Pump It Up

Lo and behold, a common thread emerged: Household cases were more abundantly distributed around the Broad Street pump. When questioned, residents reported they avoided one of the other pumps due to contamination and the other was inconveniently located. The Broad Street water pump was the primary source of water for residents – and the sole common factor between infected patients in the vicinity (1).

Snow presented his conclusions to the local authorities, convincing them to remove the handle of the pump and render it useless. Simple, yet effective. Following its removal, cholera cases plummeted and the outbreak tailed off. Though yet to be proved, Snow was a supporter of germ theory, and his investigation provided compelling evidence to support the idea that cholera was transmitted by drinking water contaminated with a germ. It was later discovered that a nappy from a baby likely infected with cholera had been washed in water that had been emptied into a cesspit that leaked into the Broad Street well.

The outbreak may seem like a distant tale from the annals of history, but its impact reverberates to this day, emphasizing the importance of community involvement in public health, social determinants of health, and evidence-based policy and practice. Though modern scientists have more advanced methods at their disposal, Snow’s work provided the basic foundation on which modern epidemiology could stand and highlighted the importance of tracking where and how a disease is spreading to help identify the source. After all, once the source is found, you can implement a rapid response to curb further spread – if only all outbreaks could be prevented with a hefty spanner.