1. Who is John Snow
Snow was a British physician who is considered one of the founders of epidemiology for his work identifying the source of a cholera outbreak in 1854.
Snow was also a pioneer in the field of anesthetics. By testing the effects of controlled doses of ether and chloroform on animals and on humans, he made those drugs safer and more effective. In April 1853, he was responsible for giving chloroform to Queen Victoria at the birth of her son Leopold, and performed the same task in April 1857 when her daughter Beatrice was born.

2. Apothecary vs. surgeon vs. MD
Surgeons were the general workers of medicine, performing a range of diagnostic and general procedure (bone setting, blood-letting, suturing, etc.).
Apothecaries dispensed drugs in general, nonsurgical practices.
MD were at the top of the heap, both as researchers and in the care of complex internal complaints as well as performance of complicated surgeries.

3. Urban life in London
For Snow, the epidemic was most severe in urban areas near the river into which the city’s sewage flowed and from which much of the city’s water was drawn.
Basic needs such as water, sewer and food accommodation was very poor because the prevailing level of technology was very poor.

4. State of Medicine and Technology
Before the days of modern technology, physicians knew little of cholera’s origins. Most of them believed that diseases such as cholera were caused by foul odors, or miasmas, in the atmosphere.
The 1840s were an increasingly public age, and those who worked at the cutting edge of science and medicine were increasingly in the public eye.

5. Snow’s work
Snow described this work in the second edition of On the Mode of Communication of Cholera. He then expanded his public health interests by becoming involved in debates over legislation concerning nuisance industries in London, while maintaining his research and practice in anesthesia until his death in 1858.

6. Cholera
A disease that that effects the small intestine caused by bacteria Vibrio cholerae
Causes diarrhea and vomiting often leads to sever dehydration. Dehydration can then lead to death
Caused by consuming contaminated water, food, or material that has been in contact with feces
Failure to treat feces and waste products is a leading cause of the spread of Cholera
Shipping seafood long distances has also been strongly linked to the spread of cholera
Treatment includes orally rehydrating to replace the lost fluids. Rehydration solution is helpful to replace lost electrolytes. IV’s can also be used to replenish electrolytes
In severe cases, antiracial medicines can be used
Today’s survival rate is about 97%. In 2010 about 4 million people were infected with Cholera and caused approximately 115,000 fatalities.
In earlier times (era of John Snow) fatality rates were significantly higher upwards of 50% fatality rate
In the 1980’s approximately 3 million people died per year as a result of cholera
Little was known about Cholera until the 20th century
Now we understand the causes, treatment process, symptoms and reasons for death

7. Key Achievements of John Snow
John Snow was an English physician that was known for the use of anesthesia and medical hygiene.
Anesthesia
One of the firsts to calculate dosage of anesthesia
Created first tool to administer anesthesia
Personally administered anesthesia to Queen Victoria
Mapped and cured the cholera outbreak of 1854 England
First known person to develop disease mapping through the topic of GIS

8. Cholera Out-break of 1854
In 1854 most people believed in the miasma theory: diseases spread though “bad air”
The germ theory (what we now believe true today) had not been discovered yet.
Without the aid of today’s knowledge, Snow mapped out infected people and researched where they had been, who they had seen, what they had done, etc.
After investigation, Snow found the source of the cholera outbreak to be the Broad Street water pump, which was located some three feet from a septic tank from an adjacent house (septic tanks of 1854 were not well contained-more like a pit of feces)
Snow is credited with the fixing the epidemic and convinced the local authorities to remove the water pump.

9. Snow’s Map of cholera infection (1854)
Snow mapped out the infections of cholera and after research was able to determine where cause of the disease was (water pump on Broad Street)

10. Snow’s Mapping Solution Today
Snow was the first known person to successfully “map” or track the spread of disease.
Today, we commonly use GIS to solve, track, and learn about the spread of diseases.
GIS plays a huge role in determining what areas are most prone to certain diseases.
Today, we know where certain diseases are common and are able to mandate shots to prevent such diseases when people are visiting over seas.
Example: when traveling to Africa, Americans have to receive certain vaccination shots to prevent against diseases that are pertinent in Africa.

11. Common Diseases We Map Today
West Nile Virus
St. Louis Encephalitis
Eastern Equine Encephalitis
Western Equine Encephalitis
La Crosse Encephalitis
Powassan Virus
Dengue Fever

12. Disease Mapping Today (West Nile)
This GIS map is an example of how GIS is able to contribute to the advancement in knowledge of the spread of diseases. The dark areas are positive test results for West Nile and the lighter areas are where there has been no positive test for West Nile. This concept is applied to all kinds of diseases.

13. Advancement of Cultural Practices-Developed countries vs
Advancement of Cultural Practices-Developed countries vs. undeveloped countries
In 1800’s Europe (and similarly developed areas) there was a lack of sanitation. Each house had a pit under it where its waste was stored. Drinking wells were located directly next to the feces pits. It is unbelievable how far developed countries’ culture has come today. Today, there are laws, regulations, and governing bodies that ensure proper sanitation of water and waste water. Unfortunately, undeveloped countries are still at the same level as 1800’s Europe where the cholera outbreak occurred. They have no waste sanitation process or equipment (or even knowledge of why it is necessary). The cultures of today’s developed countries and today’s undeveloped countries is significantly divided. In the future, undeveloped countries are going to continue to struggle with sanitary issues (cause sing diseases) unless other counties help them develop a sufficient infrastructure.

14. VMI’s Former Water Collection System
Before modern pumped and plumbing systems, VMI had to employ “rain harvesting” to supply their drinking/washing water. The Barracks is located on top of a hill, sloping downwards on all sides. This makes aqueducts of gravity impossible to supply water. Essentially, rain water was stored for later use for drinking and washing

15. VMI’s Former Toilet System
Similar to the collection of rain water for drinking use, waste (feces, urine, dirty water, etc.) accumulated form the VMI Barracks was released down the hill on the back-side of Barracks into “the Nile.”
Since Barracks is on top of a hill and cannot use gravity to accumulate water, it is possible to use gravity to get rid of used water and waste. The waste was released via gravity into the stream at the bottom of the hill.

16. “The Nile”
The Nile is the small stream that runs behind the backside of Barracks. The Nile is where waste used to be drained into. Because feces is organic, it fertilized the ground leading down from Barracks to the river. Because the land is so fertile and green (lots of trees/bushes), it was given the name the Nile.

17. Notes and References http://diseasemaps.usgs.gov/wnv_us_human.html