The Secret Behind the Map of Death, the lone warrior in 19th-century British cholera – John Snow

Fast back to the 19th century, when Britain ushered in the victory of the Industrial Revolution in the middle of the century, although the urban economy developed rapidly, but people's living environment deteriorated.

London's streets are stenchy, design-flawed sewers keep people piling up excrement, and Britain's famous River Thames, which is dirty and smelly and unbearable.

In August 1854, Louis, who lived on Broad Street in England, noticed that his young daughter was vomiting and diarrhea, and his wife, Sarah, as usual, threw her daughter's diaper into the trash can, and then put the trash can in the sewer.

A few days later, there was a massive cholera outbreak in Soho, and in a panic, more and more people left Soho, but only one person did the opposite, and this person was John Snow.

Why cholera makes people talk about discoloration

Cholera is an acute diarrheal infectious disease caused by Vibrio cholerae contamination, mainly through contaminated water or diet through oral transmission, clinical manifestations of diarrhea, vomiting, dehydration, nausea and so on.

Historical records of cholera can be traced back to the fifth century AD, and from the nineteenth century onwards, cholera began to spread on a large scale, claiming countless lives, and cholera was called the "disease of the century".

According to official records, from 1817 to today, cholera has had a total of seven pandemics, with a wide range of areas, starting in India and subsequently spreading to Europe, Africa, the Americas and other places.

The first cholera pandemic began in India, which has a long tradition of water burial, where Indians throw their bodies into the Ganges after death.

In 1817, the Ganges Flood broke out, because the water buried the corpses drifting in the Ganges, along with the flood gathered in the middle and lower reaches of the Ganges, when the Ganges was like a cholera "Petri dish", centered on the Ganges Delta, cholera quickly broke out in India, and within a few years, it spread to Thailand and the Philippines.

The first cholera pandemic did not end until 1824, when Russia was also affected, which shows the astonishing extent of its spread.

The second cholera pandemic began in Bangladesh in 1827 and spread to England in 1831, this time the famous British medical journal The Lancet published a review article on cholera.

For the first time, the article will explore the sources of cholera, as well as the routes of its transmission, and will also map the areas affected by cholera, the first time that people and academic researchers among the masses have recognized the great dangers of cholera.

In 1832, Thomas Shapter was in Exeter and experienced an outbreak of cholera, and in 1849, he formally proposed that cholera existed from person to person and spread through air, and since then " miasma " has become the mainstream theory of cholera transmission.

But john North disagrees with the "miasma theory."

Waterborne Spreads with Death Map

John Snow was born in 1813 to a miner whose father was not a very good student, but his father was visionary and provided Snow with good conditions for study.

After graduating from the University of London, Snow began working in a local hospital, where he performed anesthesia surgery for Queen Victoria because of his outstanding performance in the field of anesthesia.

When cholera first struck Britain, Snow's ideas about the way cholera spread varied from the prevailing thinking at the time.

In 1849, Snow published a paper on "cholera transmission models" in the London Medical Journal, but this paper was not later recognized by the academic community.

At that time, in order to complete the "cholera transmission model", Snow went to a local coal mine to collect samples.

In these samples, most of the miners who died of cholera did not like to wash their hands before meals and did not use knives and forks to eat.

Among these miners, some have nothing to do with the patients, and some will get sick.

Therefore, Snow believes that unhygienic people will be infected when they come into contact with patients, while hygienic people will not, and if according to the "miasma theory", there is no way to explain those who contact patients without getting sick.

Snow was an anesthesiologist himself, studying cholera was not his job, and the act of daring to question mainstream thinking at the time was in itself awe-inspiring.

Fast forward to 1854, when a cholera outbreak broke out in London's Soho district, the epidemic developed so rapidly that hundreds of people died within a few days, and the implicated civilians had to pack their bags and flee the Soho district.

But Snow, who had gotten the news, went to the center of the cholera outbreak, knowing that perhaps this time he could prove that cholera was not transmitted by air.

After coming to Soho District, he contacted his friends in the church and took advantage of his friend's position in the church to successfully enter the Soho District to investigate.

At that time, the Soho district was lifeless, and Snow casually knocked on the door of a house, and he could see the corpses of the patients grinning in the middle of the house, and the air emitted the smell of vomit fermentation, which made people feel physically uncomfortable.

In this way, Snow insisted on a household-by-household investigation, recording the number of deaths and the number of sick people, and finally, he found a map of London and marked the investigated death records on the map, which was later called the "death map".

On this map, he uses short black horizontal lines to represent the number of deaths and illnesses, most of which surround pumps at the intersection of Broad street and Cambrig street.

As snow collated the data, he found that the closer he got to the public water pump on Broad Street, the higher the death toll, which led Snow to wonder if the water source would be the route of cholera transmission.

After sharing his conjecture with everyone, he was opposed by the scholars of "miasma theory".

Little Marlborough Street is the source of the Broad Street pump, and if the water source is the source of transmission, then Little Marlborough Street should be very dangerous, but the truth is just the opposite.

These rebuttals made Snow sink his mind again, scrutinizing the details he had missed.

This time, he changed his perspective and started from a healthy population that did not have a disease.

Of all the people who are not sick, there are several groups that are very strange, and although they are at the center of the cholera outbreak, they are not affected in any way.

These categories are workers in the distillery and prisoners in prisons.

Because the liquor was free, the distillery workers hardly drank water, but only drank, and the prisoners lived in their own wells and did not drink water from the Broad Street pump.

North sorted out these details and handed over his data map to the local government, which did not quite believe Snow's words, but with the attitude of "dead horses as live horse doctors", heeded Snow's advice and removed the pump handle from Broad Street.

Soon, cholera on Broad Street stopped, and Snow was also known as the "whistleblower in cholera.".

After the end of cholera in England in 1854, Snow continued to study cholera, but the envy of talent, John Snow, died of a stroke four years later, which is regrettable.

In the first year after Snow's death, the British government began to improve the water supply system, and London greatly improved sewers, even spending six years to create the world's first modern sewer system.

John Snow was instrumental in the establishment of infectious diseases, and his "death map" is still a classic example of infectious diseases and statistics.

In his honor, future generations have made the dismantled pump handle an international symbol of public health, and in 1992 the John Snow Association was established.