He also made a solid use of statistics to illustrate the connection between the quality of the source of water and cholera cases. Snow's efforts ... Bank of England;
John Snow (physician)
From Wikipedia, the free encyclopedia
| John Snow |
 |
| Born |
15 March 1813
York, United Kingdom |
| Died |
16 June 1858 (aged 45)
London, United Kingdom |
| Citizenship |
British |
| Nationality |
English |
| Fields |
Epidemiology |
| Alma mater |
University of London |
| Known for |
Anaesthesia, locating source of a cholera outbreak, thus establishing the link between this infection and water as its vector. |
John Snow (15 March 1813 – 16 June 1858) was an English physician and a leader in the adoption of
anaesthesia and medical
hygiene. He is considered one of the fathers of modern
epidemiology, in part because of his work in tracing the source of a
cholera outbreak in Soho, London, in 1854.
His findings inspired fundamental changes in the water and waste
systems of London, which led to similar changes in other cities, and a
significant improvement in general public health around the world.
Early life and education
Snow was born 15 March 1813 in
York,
England. He was the first of nine children born to William and Frances
Snow in their North Street home. His neighbourhood was one of the
poorest in the city and was always in danger of flooding because of its
proximity to the
River Ouse. His father was a labourer
[1]
who may have worked at a local coal yard, by the Ouse, probably
constantly replenished from the Yorkshire coalfield by barges, but later
was a farmer in a small village to the north of York.
[2] Snow was baptised at
All Saints' Church, North Street, York
Snow studied in York until the age of 14, when he was apprenticed to William Hardcastle, a surgeon in
Newcastle upon Tyne. It was there, in 1831, that he first encountered
cholera, which entered Newcastle via the seaport of
Sunderland and devastated the town.
[3] Between 1833 and 1836 Snow worked as an assistant to a
colliery surgeon, first in
Burnopfield, County Durham, and then in
Pateley Bridge,
West Riding of Yorkshire. In October 1836 he enrolled at the
Hunterian school of medicine on
Great Windmill Street, London.
[4]
Career
In 1837 Snow began working at the
Westminster Hospital. Admitted as a member of the
Royal College of Surgeons of England on 2 May 1838, he graduated from the
University of London in December 1844 and was admitted to the
Royal College of Physicians in 1850. In 1850 he was also one of the founding members of the
Epidemiological Society of London, formed in response to the cholera outbreak of 1849.
[5]
In 1857 Snow made an early and often overlooked
[6] contribution to epidemiology in a pamphlet,
On the adulteration of bread as a cause of rickets.
[7]
Anaesthesia
John Snow was one of the first physicians to study and calculate dosages for the use of
ether and
chloroform as surgical
anaesthetics, allowing patients to undergo surgical and
obstetric
procedures without the distress and pain they would otherwise
experience. He designed the apparatus to safely administer ether to the
patients and also designed a mask to administer chloroform.
[8] He personally administered chloroform to
Queen Victoria when she gave birth to the last two of her nine children,
Leopold in 1853 and
Beatrice in 1857,
[9] leading to wider public acceptance of obstetric anaesthesia. Snow published an article on ether in 1847 entitled
On the Inhalation of the Vapor of Ether.
[10] A longer version entitled
On Chloroform and Other Anaesthetics and Their Action and Administration was published posthumously in 1858.
[11]
Cholera
Map of a later cholera outbreak in London, in 1866
Snow was a skeptic of the then-dominant
miasma theory that stated that diseases such as cholera and
bubonic plague were caused by pollution or a noxious form of "bad air". The
germ theory of disease
had not yet been developed, so Snow did not understand the mechanism by
which the disease was transmitted. His observation of the evidence led
him to discount the theory of foul air. He first publicised his theory
in an 1849 essay,
On the Mode of Communication of Cholera,
followed by a more detailed treatise in 1855 incorporating the results
of his investigation of the role of the water supply in the
Soho epidemic of 1854.
[12]
By talking to local residents (with the help of
Reverend Henry Whitehead), he identified the source of the outbreak as the public water pump on Broad Street (now
Broadwick Street). Although Snow's chemical and microscope examination of a water sample from the
Broad Street pump
did not conclusively prove its danger, his studies of the pattern of
the disease were convincing enough to persuade the local council to
disable the well pump by removing its handle. This action has been
commonly credited as ending the outbreak, but Snow observed that the
epidemic may have already been in rapid decline:
There is no doubt that the mortality was much diminished, as I said
before, by the flight of the population, which commenced soon after the
outbreak; but the attacks had so far diminished before the use of the
water was stopped, that it is impossible to decide whether the well
still contained the cholera poison in an active state, or whether, from
some cause, the water had become free from it.
Original map by John Snow showing the
clusters of cholera cases in the London epidemic of 1854, drawn and lithographed by
Charles Cheffins.
Snow later used a
dot map
to illustrate the cluster of cholera cases around the pump. He also
used statistics to illustrate the connection between the quality of the
water source and cholera cases. He showed that the
Southwark and Vauxhall Waterworks Company was taking water from sewage-polluted sections of the
Thames
and delivering the water to homes, leading to an increased incidence of
cholera. Snow's study was a major event in the history of public health
and geography. It is regarded as the founding event of the science of
epidemiology.
Snow wrote:
On proceeding to the spot, I found that nearly all the deaths had
taken place within a short distance of the [Broad Street] pump. There
were only ten deaths in houses situated decidedly nearer to another
street-pump. In five of these cases the families of the deceased persons
informed me that they always sent to the pump in Broad Street, as they
preferred the water to that of the pumps which were nearer. In three
other cases, the deceased were children who went to school near the pump
in Broad Street...
With regard to the deaths occurring in the locality belonging to the
pump, there were 61 instances in which I was informed that the deceased
persons used to drink the pump water from Broad Street, either
constantly or occasionally...
The result of the inquiry, then, is, that there has been no
particular outbreak or prevalence of cholera in this part of London
except among the persons who were in the habit of drinking the water of
the above-mentioned pump well.
I had an interview with the Board of Guardians of St James's parish, on
the evening of the 7th inst [7 September], and represented the above
circumstances to them. In consequence of what I said, the handle of the
pump was removed on the following day.
— John Snow, letter to the editor of the Medical Times and Gazette
Researchers later discovered that this public well had been dug only 3 feet (0.9 m) from an old
cesspit,
which had begun to leak fecal bacteria. The cloth diaper of a baby, who
had contracted cholera from another source, had been washed into this
cesspit. Its opening was originally under a nearby house, which had been
rebuilt farther away after a fire. The city had widened the street and
the cesspit was lost. It was common at the time to have a cesspit under
most homes. Most families tried to have their raw sewage collected and
dumped in the Thames to prevent their cesspit from filling faster than
the sewage could decompose into the soil.
Thomas Shapter had conducted similar studies and used a point-based map for the study of cholera in
Exeter, Devon years before John Snow, although this did not identify the water supply problem that was later held responsible.
[13]
Political controversy
After the cholera epidemic had subsided, government officials
replaced the Broad Street pump handle. They had responded only to the
urgent threat posed to the population, and afterward they rejected
Snow's theory. To accept his proposal would have meant indirectly
accepting the oral-fecal method of transmission of disease, which was
too unpleasant for most of the public to contemplate.
[14]
It wasn't until 1866 that
William Farr, one of Snow's chief opponents, realized the validity of his diagnosis when investigating another outbreak of cholera at
Bromley by Bow and issued immediate orders that unboiled water was not to be drunk.
[15]
Public health officials recognise the political struggles in which reformers have often become entangled.
[16]
During the Annual Pumphandle Lecture in England, members of the John
Snow Society remove and replace a pump handle to symbolise the
continuing challenges for advances in public health.
[17]
Later life
In 1830 Snow became a member of the
Temperance Movement, and lived for a decade or so as a vegetarian and
teetotaler.
In the mid-1840s his health deteriorated, and he returned to
meat-eating and drinking wine. He continued drinking pure water (via
boiling) throughout his adult life. He never married.
[18]
Snow lived at 18
Sackville Street, London, from 1852 to his death in 1858.
[19]
Snow suffered a stroke while working in his London office on 10 June 1858. He was 45 years old at the time.
[20] He never recovered, dying on 16 June 1858. He was buried in
Brompton Cemetery.
[21]
Legacy and honours
- A plaque commemorates Snow and his 1854 study in the place of the
water pump on Broad Street (now Broadwick Street). It shows a water pump
with its handle removed. The spot where the pump stood is covered with
red granite.
- A public house nearby was named "The John Snow" in his honour.
- The John Snow Society is named in his honour, and the society
regularly meets at The John Snow pub. An annual Pumphandle Lecture is
delivered each September by a leading authority in contemporary public
health.
- His grave in Brompton Cemetery, London, is marked by a funerary monument.
- In York a blue plaque on the west end of the Park Inn, a hotel in North Street, commemorates John Snow.
- Together with fellow pioneer of anaesthesia Joseph Thomas Clover, Snow is one of the heraldic supporters of the Royal College of Anaesthetists.[22]
- The Association of Anaesthetists of Great Britain and Ireland awards The John Snow Award, a bursary for undergraduate medical students undertaking research in the field of anaesthesia.
- In 1978 a public health research and consulting firm, John Snow, Inc, was founded.
- In 2001 the John Snow College was founded on the University of Durham's Queen's Campus in Stockton-on-Tees.
- In 2013 The Lancet
printed a correction of its brief obituary of Snow, originally
published in 1858: "The journal accepts that some readers may wrongly
have inferred that The Lancet failed to recognise Dr Snow's
remarkable achievements in the field of epidemiology and, in particular,
his visionary work in deducing the mode of transmission of epidemic
cholera."[23]
- Despite reports that Snow was awarded a prize by the Institut de France for his 1849 essay on cholera,[24] a 1950 letter from the Institut indicates that he received only a nomination for it.[25]
See also
References
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