Reference no: EM133311285

Assignment:

Late in the summer of 1854, cholera broke out once again, with a cluster of cases in the vicinity of Broad Street. This was a neighborhood that Snow knew well, having lived there for several years when he first arrived in London. By knocking on doors, Snow determined that all of the cases of cholera involved people who obtained their water from the Broad Street pump. Most of the victims lived closest to this pump; among those who did not were children who went to a school on Broad Street near the pump and a handful of people who preferred the taste of the water of the Broad Street pump to that of water from other pumps nearer their homes.

At that time, the local parish, St. James Church, was responsible for taking care of poor families in the neighborhood. A Parish Board was responsible for making decisions on how to provide charitable assistance. Snow went to the Board and made his case, arguing that the handle on the pump should be removed to prevent further cases of cholera. Although those on the board were skeptical, they decided that Snow's proposal would do no harm, and the handle was removed. Cases of cholera dropped.

Reverend Henry Whitehead, the minister of St. James Church, was skeptical of Snow's explanation and saw a critical flaw in Snow's work. Snow had focused on interviewing those households affected by the epidemic. As the parish priest, he had ministered to the sick and dying during the epidemic. Whitehead decided to interview people in households in which no one died from cholera. Much to his chagrin, he found that households using the Broad Street pump were nine times more likely to have cholera victims than those not using it. Through his careful interviewing, Whitehead also succeeded in identifying an earlier case, an infant living in a house a few feet from the Broad Street pump who died from diarrhea two days before the cholera outbreak was officially recognized.

Although Whitehead had initially sought to criticize Snow's work, the two became allies. Together, Whitehead and Snow asked the Board of Public Health to excavate the area around the pump. There, they found that water from the cesspool under the building where the first infant victim died was seeping out and into the water from the pump. On further inquiry, they learned that the baby's mother had washed the soiled diapers of her sick infant in the basement of her building, dumping the water in the cesspool.

Although many continued to reject Snow's explanation, some began to give it grudging acceptance, often without acknowledging his contribution. Snow's vindication came at a meeting of the Medical Society where a member stood up after such a presentation insisting that Snow be given credit. Sadly, not long after this, Snow suffered a series of strokes, dying at the age of 45.

The following summer, a drought compounded the problems of contamination of the Thames, resulting in pollution so severe that it was called the Great Stink. Members of Parliament were forced to meet in a remote location because of the stench, where they voted to initiate a vast construction project to move the sewer pipes far downstream. After the construction of the new sewer system, there were no more cholera outbreaks in England.

Questions

1. Epidemiology relies on non-experimental tests. What was Snow's observational hypothesis and how did he test it?

2. How did Whitehead improve on Snow's test of this hypothesis?

3. What was the experimental test of their hypothesis?

4. Define and describe the difference between correlation and causation? How does that apply to this study?

5. Describe your reaction to this case study in light of the current SARS-CoV-2 pandemic. What do you think people 100 years from now will look back at us and think of our response?

6. The water from the Broad Street pump had a reputation for tasting better than the surrounding water. There was outrage initially when the pump handle was removed. Imagine social media was a thing back then and develop a post or meme you can imagine seeing in response to these events.