THE COLOR OF DEATH: BLUE

V. cholerae has always existed in the warm and muddy waters of Indian rivers, and while locals have of course occasionally contracted cholera, some of the population had a fairly persistent immunity to it, developed over thousands of years. But this disease did not become a pandemic for a long time because it did not have time to spread. Without a fast mode of transportation, a rapidly emerging disease cannot become global or even cover much of the world. Until the modern era, pathogens generally did not travel well. They were usually carried over long distances by vector animals that did not die from the disease themselves, but could carry it in their bodies for a long time. Such were the plague epidemics. A disease could also spread far from where it originated if the infection was slow and the traveler did not feel sick for a long time.iThis was perhaps how syphilis came to the Old World from the Americas after Columbus’s explorations.

Colonization, rapid transportation, and mass movement of people from one part of the world to another (such as soldiers, sailors, officials, refugees, et cetera) created the right conditions for pathogens to spread much more rapidly across the planet. And this is exactly what happened with cholera.

There have been seven cholera pandemics in the last 200 years, and the seventh is believed to be underway. The first cholera pandemic began in 1817 and lasted about seven years. According to medical experts of the time, cholera broke out in the city of Jessore, which is now in Bangladesh but was then part of British India. The Padma River, a tributary of the Ganges, flows through Jessore, and a waterborne spread of infection across the vast Indian subcontinent seems a very realistic scenario. The mutation of V. cholerae, which made the disease much more dangerous, led to the deaths of many people even among cholera-resistant Indians, while British soldiers had absolutely no protection from the scourge. An epidemic broke out among the troops stationed in India, and V. cholerae traveled the world with British soldiers and sailors.

For most of the nineteenth century (while the true bacteriological cause of infection was still unclear), cholera was perceived in Britain as a barbaric, foreign, and primarily Indian disease. Its appearance in Europe caused fear, confusion, and outrage. At the time, people, including scientists, thought that diseases were mostly caused by the peculiarities of terrain and climate. Thus, a cholera outbreak in Europe was as shocking as if Paris and London had been invaded by wild elephants!iAncient physicians, including Hippocrates, mention ‘cholera’, but it is unclear whether they mean the same disease.

In popular European newspapers and magazines, cholera was depicted either as a skeleton or as an Indian wearing a turban. And this Indian villain, if the illustration was colored, was usually painted blue. The most typical symptom of cholera is excruciating, incessant diarrhea, but the propriety of the times did not usually permit such images to be published. Artists focused on another characteristic of cholera—the darkening (turning blue if you’re being a little imaginative) of the body due to dehydration. Thus, a skinny blue Indian invader was how cholera was depicted. What was most frightening was how quickly the disease affected you. A person who was perfectly healthy in the morning could suffer from constant vomiting and terrible stomach upset during the day, fall into oblivion at night, and be dead by dawn.

The second cholera pandemic, which, according to some reports, began as usual in India, spread through Asian countries and reached the Russian Empire in the early 1830s, resulting in the deaths of about 100,000 Russian subjects. Because of the quarantine, the roads in much of the empire were closed. That’s when Pushkin’s famous Boldino autumn took place.

From Russia, cholera spread to Europe, where it killed at least as many people as in Russia and perhaps more. It struck Asia and North Africa with terrible force, killing at least 150,000 people in Egypt alone in the early 1830s. Cholera cemeteries became vast necropolises. By the mid-1830s, the disease had reached North America. The New York City Board of Health issued desperate (and completely useless) recommendations, including abstaining from alcoholic beverages. Sobriety is a good thing, of course, but it has nothing to do with cholera.

The third cholera pandemic swept the world in the mid-nineteenth century, from about 1846 to 1860. Its global reach was wider than the previous pandemics, and the number of victims was greater: about 1 million people died in Russia alone. This cholera outbreak is described in the memoirs of children’s author and memoirist Elizaveta Vodovozova as:

My deceased father was still on his deathbed when cholera struck my two elder sisters, one nineteen and the other eighteen years old, and they were buried one after the other. Over the next three weeks, cholera took four more children from our family. So in the course of about a month, we had seven dead. Many people asked my mother afterwards why she did not go to her estate immediately after my father’s death: by doing so, she would probably have interrupted the severe cholera epidemic. There was, of course, only one answer: from the time my father fell ill and during the whole period that followed, not a week went by without a funeral and serious illness, and it was unthinkable to transport such patients on the bumpy country road.

During the third cholera pandemic, the disease swept through Victorian London several times. It was there that a crucial but initially unrecognized breakthrough in epidemiology occurred. This advancement was made by a doctor named John Snow.iJohn Snow was almost the namesake of Jon Snow, the character in the Game of Thrones universe. John was more important to the fate of humanity, though he is less well known.

John Snow was born in the city of York in 1813. He was the eldest of nine children, and his father was a coal miner who later became a farmer. The neighborhood where the Snows lived was one of the poorest in the city.

John proved to be a very capable and intelligent child, and at the age of fourteen, he became a medical apprentice (or, as we would say today, an intern). From 1837, Snow worked at the Westminster Hospital opposite Westminster Abbey in the heart of London. At the same time, he received his medical training at the University of London, graduating in 1844. He then set up a practice and settled in one of London’s respectable neighborhoods. Normally, physicians with a good practice preferred to care for wealthy or influential patients, thus ensuring their own well-being. But Snow was not just a doctor—he was a researcher. In 1850, after a cholera outbreak, an epidemiological society was formed in London, and Snow became one of its founders. He studied epidemiology in all its forms and was the author of an important paper on the epidemiology of rickets.

In addition, as a medical practitioner, he had always been interested in anesthesia. Snow studied the effects of anesthetics, such as ether and later chloroform, conducting experiments on himself. Chloroform was much more effective than ether, but its use required great care and precision. Snow developed devices to administer both ether and chloroform that prevented, or at least greatly reduced, the possibility of an overdose, which was associated with problems and even death. This invention brought him fame and fortune, thanks largely to the Queen of England.

The very first book of the Bible, Genesis (3:16), says, ‘In sorrow thou shalt bring forth children.’ Like many biblical statements, this promise was taken literally in certain church circles, and the idea of anesthesia for childbirth seemed sacrilegious. Nevertheless, in April 1853, when Queen Victoria was about to give birth to her eighth child, she asked Snow for anesthesia, and Prince Leopold was subsequently born under anesthesia. And Queen Victoria’s last, ninth child, Princess Beatrice, was born in April 1857, where Snow once again acted as anesthesiologist.

In the mid-nineteenth century, the idea of the contagiousness of certain diseases (epidemics) was far from being an established scientific fact. This line of thinking dates back to the ancient Greek historian Thucydides, who described the mysterious ‘Athenian plague’ that killed the ruler Pericles and thousands of Athenians, and which he himself had contracted. Still, nothing was clear, even nearly twenty-five centuries later. There were certainly physicians who believed that person-to-person transmission was the primary route of infection. But what was transmitted and what made a person sick, no one knew.

More influential than the proponents of ‘contagion’ in the medical world were the proponents of the idea of ‘miasma’. The word was used to denote some ‘infectious agents’ that lived or somehow arose in the environment. However, their nature was also unknown. In any case, very few people thought that they could be living beings, even if they were very small. The cause of epidemic diseases was most often considered to be ‘bad and unhealthy’ air. Some people thought that miasma was necessarily characterized by an unpleasant odor, but there was no consensus on this either.

Some details of various epidemic outbreaks, however, cast doubt on the miasma theory. For example, in 1848, the steamship Elbe arrived in London from Hamburg. One of the passengers who disembarked was already ill and soon died of cholera in an inn. A few days later, the same thing happened to another guest who was staying in the same room. Both were treated by the same doctor, who remained healthy and did not get sick. This did not make much sense in the framework of the miasma concept. A steamship and a hotel room were certainly different ‘environments’, while the chain of infection from person to person was quite obvious.

Snow concluded that something had to physically penetrate a person to infect them. It was not enough to inhale ‘bad air’, otherwise the doctor who treated the guests of the ill-fated hotel would also have become ill. In 1849, Snow published his thoughts in the London Medical Gazette. In late August 1854, another cholera outbreak swept through London’s Soho district. The neighborhood was served by two water companies, the Southwark and Vauxhall Waterworks Company and the Lambeth Waterworks Company that drew water directly from the Thames. This water, however, received little or no treatment.

Over the course of three days in early September, 127 people who lived on or near Broad Street died. Over the next week, three quarters of all residents left the neighborhood. By 10 September, more than 500 people had died, and by the time the outbreak had subsided, more than 600 people had died. However, the residents of other streets in Soho had fared well.

Snow recruited Henry Whitehead, an Anglican minister in Soho, to help him get to the bottom of the situation. Together, they went door to door interviewing residents. Their questions focused on two main topics: first, whether there were any cholera cases in the family; and second, what their source of drinking water was. Snow was convinced that the answer lay in the water.

The fact that Snow was able to convince a parish priest of his theory may not seem like much of an accomplishment. But Reverend Whitehead’s actions in 1855 were ultimately as important as Snow’s own. After reading Snow’s monograph, he went in search of ‘patient zero’ and eventually found Lewis, the sickly infant whose diapers had triggered the outbreak. The column tank on Broad Street was only three feet from a cesspool, and its contents had leaked into the tank. The cesspool contained water used to wash the diapers of a child who had cholera, although it's uncertain where the child actually contracted the disease.

The picture was clear: those who had drunk water from the public tap on Broad Street became ill and, in most cases, died. Those who used other sources of water, such as another standpipe, remained healthy. Snow tested the water chemically and examined samples under a microscope. These studies did not tell him anything definitive. Nevertheless, he felt that the survey data gave him enough reason to act, and he persuaded the local authorities to close the tap.

The cholera outbreak in Soho ended immediately. Snow was well aware that the epidemic might simply have run its course, in which case the sanitary and epidemiological measures he had instituted were not the cause, but an add-on. But the fact remained that the outbreak was over.

Snow made a map showing the number of households around the column on Broad Street and the number of sick people on the block. This map clearly showed that the disease seemed to be concentrated around a single point—the faucet.

‘These circumstances being taken into account,’ wrote John Snow, ‘it will be observed that the deaths either very much diminished, or ceased altogether, at every point where it becomes decidedly nearer to send to another pump than to the one in Broad Street. It may also be observed that the deaths are most numerous near the pump where the water could be more readily obtained.’

Interestingly, there was a brewery on Broad Street that continued to operate during the outbreak, but none of the brewers got sick. Snow found out that the brewery workers didn’t drink any water on the job at all, preferring to stay hydrated with their own beer and ale. The brewery’s rules allowed this—ale tasted better than water, and drinking beer and ale was generally considered healthy at the time. It must also be said that ale was, in many cases, actually safer than drinking unboiled water at the time. Snow added information about the new experience to his article on cholera, which he had written in 1849:

The most terrible outbreak of cholera which ever occurred in this kingdom, is probably that which took place in Broad Street, Golden Square, and the adjoining streets, a few weeks ago. Within 250 yards of the spot where Cambridge Street joins Broad Street, there were upwards of 500 fatal attacks of cholera in 10 days. The mortality in this limited area probably equals any that was ever caused in this country, even by the plague; and it was much more sudden, as the greater number of cases terminated in a few hours. The mortality would undoubtedly have been much greater had it not been for the flight of the population. … [I]n less than six days from the commencement of the outbreak, the most afflicted streets were deserted by more than three quarters of their inhabitants.

After the Broad Street outbreak ended, Snow continued to study the pathophysiology of cholera. He came to the firm conclusion that cholera was transmitted by what modern medicine calls the fecal-oral route.

Popular medical techniques of the time, such as bloodletting, were, in his (correct) opinion, utterly useless. Snow also insisted that cholera was not transmitted by miasmas.

However, the idea that cholera could be transmitted by the fecal-oral route was so unpalatable that it was impossible for the public, and even the medical profession of the time, to believe. Immediately after the outbreak, officials restored the water tap. It took many more years for people to fully understand how cholera spread and to realize the effectiveness of simple preventive measures that could stop an epidemic.

‘You and I may not live to see the day,’ Snow wrote to his assistant, the curate Henry Whitehead, ‘and my name may be forgotten when it comes; but the time will arrive when great outbreaks of cholera will be things of the past; and it is the knowledge of the way in which the disease is propagated which will cause them to disappear.’

Unfortunately, Snow was right: he was not destined to live to see such a day. A commission convened to investigate the causes of the cholera epidemic and how to prevent similar occurrences in the future came to very different conclusions.

The logic of the Cholera Commission’s report, paraphrased in plain English, was as follows: ‘Cholera thrives in unventilated, crowded spaces where unsanitary conditions and noxious smells abound. We have examined the Broad Street area, and found it to be an unventilated, crowded space where unsanitary conditions and noxious smells abound. What more do you need?’

In an unsigned editorial, the prestigious medical journal The Lancet openly mocked Snow:

‘Why is it, then, that Dr Snow is so singular in his opinion? Has he any facts to show in proof? No! … But Dr Snow claims to have discovered that the law of propagation of cholera is the drinking of the sewage-water. … In riding his hobby very hard, he has fallen down through a gully-hole and has never since been able to get out again.’

Believe it or not, that was the writing style of scientific journals in the middle of the nineteenth century!

In June 1858, London was struck by the ‘Great Stink’. The sewage that had been dumped into the waters of the Thames began to emit an unbearable stench due to the heat, which led to the disruption of all city life, including Parliament, whose building stands on the banks of the river

And it was at that time that Dr Snow suffered a stroke and died a week later at the age of forty-five. The Lancet published a terse obituary: ‘DR. JOHN SNOW — This well-known physician died at noon on the 16th instant, at his house in Sackville Street, from an attack of apoplexy. His research on chloroform and other anaesthetics was appreciated by the profession.’ There was not a word about his work on cholera.

However, a plaque installed in 2008 by the Royal Society of Chemistry near the site of the ill-fated tap celebrates Snow’s achievements in a very different way, calling him the ‘Founding Father of Epidemiology’.

The next, fourth, cholera pandemic occurred between 1863 and 1875. By this time, the connection between unclean water and the disease had been recognized not only by medical professionals but also by the general public. Thus, in 1866, a Washington oyster merchant prematurely announced in a newspaper advertisement: ‘CHOLERA PANIC OVER’, indicating that there was nothing more to fear. It must be said that shellfish living in waters where sewage enters and eaten raw are a very common and significant source of V. cholerae in humans.

The fifth pandemic occurred at the end of the nineteenth century, roughly from 1881 to 1896. One of the victims of this cholera pandemic in 1893 was the composer Pyotr Ilyich Tchaikovsky. While dining at the fashionable Leiner’s Restaurant in St. Petersburg, he asked for a glass of unboiled water drawn directly from the Moika River. According to legend, the composer, impressed by his own opera The Queen of Spades, wanted to challenge his fate. The next day, he fell ill, and he died four days later at the age of fifty-three. Indirectly, this story indicates that by this time people had a good understanding of how the rules of sanitation and hygiene worked. And Tchaikovsky, if all this is true, really did play faro with death. However, outside of fancy restaurants and aristocratic households, it was difficult to provide people with enough clean water and antiseptics.

It was during these years that the German microbiologist Robert Koch identified V. cholerae as the causative agent of cholera, although he was unable to demonstrate with certainty that this bacillus caused cholera in healthy people. Because the vibrio looks like a comma under the microscope, it also became known as ‘Koch’s comma’.

In addition, it was later discovered that the bacillus had been described earlier by the Italian anatomist Filippo Pacini in 1854, during a cholera outbreak in London.

The sixth pandemic raged for most of the first quarter of the twentieth century. Like all the previous ones, it began in India and spread to the Middle East, North Africa, and Eastern Europe, including Russia.

The seventh pandemic occurred between 1961 and 1975, but the strain that caused it, known as El Tor, still exists today, which is why a number of doctors and medical organizations, including the World Health Organization (WHO), believe that this cholera pandemic should be considered ongoing.

In the late nineteenth century, the French-Russian Jewish bacteriologist Waldemar (Vladimir) Haffkine attempted to create a vaccine against cholera. But his older colleagues, including prominent bacteriologists Ilya Mechnikov and Louis Pasteur, were skeptical of his achievements. Apparently, they were right—the first effective anti-cholera vaccines were not developed until the 1980s.

WHO currently recommends three vaccines (Dukoral, Shanchol, Euvichol-Plus), primarily for people living in disadvantaged areas (especially in Africa) and for travelers and healthcare workers who go there.

Under modern conditions, with qualified and, above all, prompt medical care, cholera is not particularly dangerous. First, only about 10 per cent of those who are infected—those whose bodies have been exposed to sufficient quantities of V. cholerae—show symptoms requiring hospitalization. Of those, 99 per cent will recover with proper treatment, which consists mainly of rehydration therapy. This restores essential fluids and chemicals that were washed out of the body by the digestive upset. In severe cases, antibiotics and zinc supplements are also used.

And of course, the old rules—don’t drink unboiled water, don’t eat unwashed food, wash your hands more often—are relevant to everyone today.

Johnson, Steven. 2006. The Ghost Map. A Street, an Epidemic and the Hidden Power of Urban Networks. London: Penguin Books.

Shah, Sonia. 2017. Pandemic: Tracking Contagions, from Cholera and Ebola and Beyond. London: Picador.