Джон Сноу: Пионер эпидемиологии и медицинской гигиены

English epidemiologist and physician (1813–1858)
the physician

John Snow (15 March 1813 – 16 June 1858) was an English physician and a leader in the development of anaesthesia and medical hygiene. He is considered one of the founders of modern epidemiology and early germ theory, in part because of his work in tracing the source of a cholera outbreak in London's Soho, which he identified as a particular public water pump. Snow's 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.

Snow was born on 15 March 1813 in York, England, the first of nine children born to William and Frances Snow in their North Street home, and was baptised at All Saints' Church, North Street, York. His father was a labourer who worked at a local coal yard, by the Ouse, constantly replenished from the Yorkshire coalfield by barges, but later was a farmer in a small village to the north of York. The neighbourhood was one of the poorest in the city, and was frequently in danger of flooding because of its proximity to the River Ouse. Growing up, Snow experienced unsanitary conditions and contamination in his hometown. Most of the streets were unsanitary and the river was contaminated by runoff water from market squares, cemeteries and sewage. From a young age, Snow demonstrated an aptitude for mathematics. In 1827, when he was 14, he obtained a medical apprenticeship with William Hardcastle in the area of Newcastle upon Tyne. In 1832, during his time as a surgeon apothecary apprentice, he encountered a cholera epidemic for the first time in Killingworth, a coal mining village. Snow treated many victims of the disease and thus gained experience. Eventually he adjusted to teetotalism and led a life characterized by abstinence, signing an abstinence pledge in 1835. Snow was also a vegetarian and tried to only drink distilled water that was "pure".

In the 1830s, Snow's colleague at the Newcastle Infirmary was surgeon Thomas Michael Greenhow. The surgeons worked together conducting research on England's cholera epidemics, both continuing to do so for many years. 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. Snow was a founding member of the Epidemiological Society of London which was formed in May 1850 in response to the cholera outbreak of 1849. By 1856, Snow and Greenhow's nephew, Dr. E. H. Greenhow were some of a handful of esteemed medical men of the society who held discussions on this "dreadful scourge, the cholera". After finishing his medical studies in the University of London, he earned his MD in 1844. Snow set up his practice at 54 Frith Street in Soho as a surgeon and general practitioner. John Snow contributed to a wide range of medical concerns including anaesthesiology. He was a member of the Westminster Medical Society, an organisation dedicated to clinical and scientific demonstrations. Snow gained prestige and recognition all the while being able to experiment and pursue many of his scientific ideas. He was a speaker multiple times at the society's meetings and he also wrote and published articles. He was especially interested in patients with respiratory diseases and tested his hypothesis through animal studies. In 1841, he wrote, On Asphyxiation, and on the Resuscitation of Still Born Children, which is an article that discusses his discoveries on the physiology of neonatal respiration, oxygen consumption and the effects of body temperature change. In 1857, Snow made an early and often overlooked contribution to epidemiology in a pamphlet, On the adulteration of bread as a cause of rickets.

Snow's interest in anaesthesia and breathing was evident from 1841 and beginning in 1843, he experimented with ether to see its effects on respiration. Snow published an article on ether in 1847 entitled On the Inhalation of the Vapor of Ether. A longer version entitled On Chloroform and Other Anaesthetics and Their Action and Administration was published posthumously in 1858. Although he thoroughly worked with ether as an anaesthetic, he never attempted to patent it; instead, he continued to work and publish written works on his observations and research.

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 fecal oral route of disease transmission, which was too unpleasant for most of the public to contemplate. It was not until 1866 that William Farr, one of Snow's chief opponents, realised 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. Farr denied Snow's explanation of how exactly the contaminated water spread cholera, although he did accept that water had a role in the spread of the illness. In fact, some of the statistical data that Farr collected helped promote John Snow's views. Public health officials recognise the political struggles in which reformers have often become entangled. 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.

Snow was known to swim as a hobby for exercise. He embraced a lacto ovo vegetarian diet by supplementing his vegetables with dairy products and eggs for eight years. Whilst in his thirties he became a vegan. In 1830, Snow became a member of the temperance movement. In 1845, he became a member of York Temperance Society. Snow suffered a stroke while working in his London office on 10 June 1858. He was 45 years old at the time. He never recovered, dying six days later on 16 June 1858. He was buried in Brompton Cemetery. It has been speculated that his premature death may have been related to his frequent exposure and experimentation with anesthetic gases, which is now known to have numerous adverse health effects. Snow administered and experimented with ether, chloroform, ethyl nitrate, carbon disulfide, benzene, bromoform, ethyl bromide and dichloroethane during his lifetime.

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. 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. Despite reports that Snow was awarded a prize by the Institut de France for his 1849 essay on cholera, a 1950 letter from the Institut indicates that he received only a nomination for it. 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 2003 John Snow was voted by readers in the United Kingdom of 'Hospital Doctor' magazine as 'the greatest doctor of all time'. In 2009, the John Snow lecture theatre was opened by Anne, Princess Royal, at the London School of Hygiene & Tropical Medicine. 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." In 2016, Katherine Tansley published a fictionalised account based on Snow's activities, in her historical novel The Doctor of Broad Street (Troubadour Books). In 2017 York Civic Trust erected a memorial to John Snow in the form of a pump with its handle removed, a blue plaque and an interpretation board, in North Street Gardens, York, close to his birthplace. The 2019 TV series Victoria in the third season episode "Foreign Bodies", John Snow meets Queen Victoria (no date mentioned but this happened in 1854) and, with the Queen's help, has the local authorities remove the Broad Street pump handle. (They did not mention his 1853 use of chloroform on the Queen for childbirth.)