Theory-Based Research Eyle, John. Changing

Theory-Based Research Eyle, John. Changing assessments of John Snow's and William Farr's cholera studies. Series: History of epidemiology. John Snow is known as the founder of modern epidemiology. Summarize his works and findings describing the premise on which his experiments were formulated.

How did Snow explain that cholera's first symptoms were abdominal pains? How does his work demonstrate the scientific method? What occupational position did William Farr hold? What significant information did Farr compile in relation to the cholera outbreaks? What were the factors he contributed to the spread and mortality of cholera? What was the vector (mode of transmission) that Farr attributed to the person-person spread of cholera? Briefly comment on the impact of Farr's work on Snow's and vice versa.

The Englishman John Snow today is called one of the fathers of modern epidemiology. However, although during his lifetime he was esteemed for his use of anesthesia, his studies of cholera were initially greeted with less open receptiveness than his medical practices relating to the field of surgery. Snow's first insight occurred when he observed the localization of the disease's symptoms to the gut, and his note that cholera did not produce generalized symptoms like other epidemics transmitted through air as opposed to water-born particles.

For example, cholera produced no symptoms such as fever or general malaise. Cholera also responded, in its early stages, to localized, targeted treatment in the form of chalk, charcoal, and opium, which were also used to treat gastrointestinal disorders at the time. However, the fact that Snow embarked upon his studies with fairly predetermined conclusions in a somewhat haphazard manner spurred resistance in the scientific community.

Snow used empirical observation and research, supported later with statistical analysis, but he had no clear 'method' of going about his conclusions, rather he used a variety of methods. One could say that Snow's antithesis in methodology was William Farr, Superintendant of the General Registrar's Office, London's Bureau of Vital Statistics. Although Farr believed that Snow was on the wrong lead in his tracing of the causes of the epidemic, the mathematically-minded Farr was sympathetic to Snow, and eventually provided valuable data that supported Snow's somewhat intuitive conclusions.

Farr had a far more scrupulously scientific approach that appealed to the Victorian scientific mind. At first, Farr's finding that there was a mathematical correspondence between soil elevation and the chances of contracting the disease was thought of far more value than Snow's observations about cholera's manifestations in patients. Farr's findings, while indeed accurate, were determinate of correlations, not causality of the disease. Farr incorrectly attributed the origins of cholera to soil fermentation, while Snow was more concerned quality of the water supply and concentrations of outbreaks of the epidemic.

Snow's beliefs regarding the disease as having an ingested source were in doubt because of the fact that individuals with close contact to potentially diseased water, like washerwomen and members of the 'untouchable' class in India, did not seem to show higher rates of contracting the illness (Eyler 227). On the part of his fellow scientists, Snow's research was resisted because it was conducted with intellectual 'leaps' of logic in his determination to find the cause, as opposed to Farr's more technical and methodological approach.

Farr had the more comprehensive health surveillance program, but Snow's hypothesis and instincts were correct. Snow drew upon past studies involving smallpox, cowpox, and syphilis, to extrapolate parallel examples of how the disease was transmitted, while Farr clung to the airborne model of disease transmission popular at the time even after reviewing such studies. Farr stated that non-living or zymotic material was transmitted through the air, and hence the closer the quarters of the affected, the more apt the material would be transmitted through the air.

The commonly-held belief was that fecalized air and water were the primary conduits of the disease. Farr believed primarily that the transmission was "miasmatic" and the prevalence in certain areas like slums and prisons, where close contact by air-born bacteria was thought to be prevalent supported this conclusion. Models that confirm rather than contradict existing evidence are altogether more 'comforting' to the scientific community.

To his credit, however, Farr did concede that the waters were highly polluted in areas where the epidemics had occurred, although he disagreed with Snow's conclusions that water was the primary means of transmission. As far as Farr was concerned, sewage-filled water was simply a conduit for air-born miasma. But as he examined statistics over a period of time, it became clear that the epidemics were largely concentrated around the.