3.1 John Snow

“31 August 1854, 127 people on or near Broad Street died. In the next week, three quarters of the residents had fled the area. By 10 September, 500 people had died and the mortality rate was 12.8 percent in some parts of the city. By the end of the outbreak, 616 people had died…”

– John Snow remarking on the cholera outbreak

John Snow - a British epidemiologist - was skeptical about miasma theory. With the help of Henry Whitehead, Snow was able to talk to patients and residents and using a dot map, locate the cases:

John Snow's Dot Map

Figure 3.2: John Snow’s Dot Map

Snow also used statistics - he eventually found that there was a connection between the cholera outbreak and a water pump that was located on Broad Street.

From this, Snow found that the source of the disease was caused by the contamination of the Thames river by a faulty sewage tank!

3.1.1 Significance of the Snow’s work

Not only was miasma theory debunked, but Snow also became the father of modern epidemiology.

However, his work demonstrated the following features:

  1. Talking to others
  2. Use of demographics and geography
  3. Use of statistics
  4. Stakeholder’s assistance (i.e., Whitehead)
  5. Importance of environmental determinants of human health.
  6. Demonstrated importance of a collaborative, multi-disciplinary, and an integrated approach.