EPM101 Fundamentals of Epidemiology
Epidemiology Taster Session

Historical Evolution of Epidemiology

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It looks as if this may be so, but we don't have enough information to be sure. Although there were more deaths in houses supplied by the Southwark and Vauxhall company, this could just be because this company supplied water to a greater number of people. In order to know whether one company is more likely to transmit contaminated water, we need to know, for each company, the number of deaths as a proportion of the number of people supplied with water.
In fact we don't have enough information to answer this question. Although there were more deaths in houses supplied by the Southwark and Vauxhall company, this could just be because this company supplied water to a greater number of people. In order to know whether one company is more likely to transmit contaminated water, we need to know, for each company, the number of deaths as a proportion of the number of people supplied with water.
That's right. Although there were more deaths in houses supplied by the Southwark and Vauxhall company, this could just be because this company supplied water to a greater number of people. In order to know whether one company is more likely to transmit contaminated water, we need to know, for each company, the number of deaths as a proportion of the number of people supplied with water.

Cholera reappeared in London in June 1853. John Snow asked permission to obtain (from William Farr) the addresses of people who died of cholera in the districts which received water supplies from both the Southwark and Vauxhall and the Lambeth companies.

He then visited the homes of all recorded cholera deaths in these districts, to get information about which company supplied water to the household. The table shows his results for the first 334 deaths.

Source of Water No. of Deaths
Southwark & Vauxhall 286
Lambeth Company 14
Direct from river 22
Pumpwells 4
Ditches 4
Unknown 4

On the basis of these figures, which company is more likely to be transmitting "morbid matter" causing cholera? Think about this for a moment, and write down the reason for your answer before you continue.

Southwark and Vauxhall

Lambeth

Can't tell

It looks as if this may be so, but we don't have enough information to be sure. Although there were more deaths in houses supplied by the Southwark and Vauxhall company, this could just be because this company supplied water to a greater number of people. In order to know whether one company is more likely to transmit contaminated water, we need to know, for each company, the number of deaths as a proportion of the number of people supplied with water.

In fact we don't have enough information to answer this question. Although there were more deaths in houses supplied by the Southwark and Vauxhall company, this could just be because this company supplied water to a greater number of people. In order to know whether one company is more likely to transmit contaminated water, we need to know, for each company, the number of deaths as a proportion of the number of people supplied with water.

That's right. Although there were more deaths in houses supplied by the Southwark and Vauxhall company, this could just be because this company supplied water to a greater number of people. In order to know whether one company is more likely to transmit contaminated water, we need to know, for each company, the number of deaths as a proportion of the number of people supplied with water.