User:Adwowk1

Week 4 Homework

Did You Know? - Did you know that people used to think that Cholera was caused by particles in the air?

Background

London had already suffered from a "series of debilitating cholera outbreaks" which included an outbreak in 1832 and 1849 which killed 14,137 people.

Competing Theories of Cholera

Preceding the 1854 Broad Street cholera outbreak there were two competing theories on the causes of cholera in the human body. The London medical community debated between Miasma theory and Germ theory as two possible causes for the persistent cholera outbreaks in the city. The Cholera causing gram negative bacteriumVibrio Cholerae, would not be first isolated until 1854, ironically the same year as the Broad street cholera outbreak, and would be first publicized by Robert Koch, a German Physician and Bacteriologist until 1883.

Miasma Theory:

Miasma theorists concluded that cholera was caused by disease causing particles in the air, or miasmata which arose from decaying organic matter or other other dirty organic sources. "Miasma" particles were considered to travel through the air and infect individuals and cause cholera. Dr. William Farr, the commissioner for the 1851 London census and a member of the General Register's Office concluded that miasma arose from the soil surrounding the River Thames. The soil surrounding the river contained decaying organic matter which contained miasmatic particles and were released into the London air. Miasma theorists believed in "cleansing and scouring, rather than through the purer scientific approach of microbiology". Dr. William Farr later agreed with John Snow's Germ Theory following Snow's publications.

Germ Theory:

In contrast to the Miasma theory, the Germ Theory behind the cause of cholera labeled the principle cause of cholera as a germ cell that had not yet been identified. John Snow theorized that this unknown germ would be transmitted from person to person by ingesting water. John Simon, a pathologist and the lead medical officer for London labeled John Snow's Germ Theory as "Peculiar".

Excerpt from John Simon:

"This doctrine is, that cholera propagates itself by a ‘morbid matter' which, passing from one patient in his evacuations, is accidentally swallowed by other persons as a pollution of food or water; that an increase of the swallowed germ of the disease takes place in the interior of the stomach and bowels, giving rise to the essential actions of cholera, as at first a local derangement; and that ‘the morbid matter of cholera having the property of reproducing its own kind must necessarily have some sort of structure, most likely that of a cell." 

Even though Simon understood John Snows theory he called into question Germ theories relation to the cause of cholera.

Dr. Edwin Lankester's Evaluation

Dr. Edwin Lankester, a physician who was part of a local research conglomerate that studied the 1854 Broad Street Cholera Epidemic. In 1866 Dr. Lankester came to his conclusion that the pump itself was the cause of the Cholera outbreak. He agreed with John Snow, however his opinion, like Snow's, was not publicly supported. Lankester eventually was named the first medical officer of health for the St. James District in London. This was the same area where the pump was located. Lankester subsequently closed the pump due to his theory on the source of cholera in the area and infection rates dropped significantly.

John Snows Post Outbreak Evaluation

John's Snow's analysis of cholera and cholera outbreaks extended past the closure of the Broad Street Pump. John Snow concluded that cholera was indeed transmitted through and affected the alimentary canal within the human body. Cholera did not affect either the circulatory or the nervous system and there was no "poison in the blood...in the consecutive fever...the blood became poisoned from urea getting into the circulation". According to John Snow this "urea" would enter through Kidney Failure. (Acute Renal Failure is a complication of Cholera)

Therefore the fever itself would be caused by kidney failure, not by a poison already present in the subjects bloodstream. Popular medical practices such as bloodletting would therefore yield itself not effective in this case. John Snow also argued that Cholera was not a product of the Miasma theory. "There was nothing in the air to account for the spread of cholera". Cholera according to Snow was indeed spread by ingesting a substance, not through atmospheric transmittal. Snow cited that two sailors, one with cholera and one without, eventually both became sick from ingesting bodily fluids accidentally.

The Broadwick Street Pump Today

There is currently a replica pump where the original pump stands. The original location of the pump is marked by a red granite paver. Every year the John Snow soceity holds a ceremony where they remove and reattach the pump to pay tribute to John Snow's historic discovery.