Contagious Cartography: A Panorama of Pandemics and Plagues
The vocabulary of disease runs parallel with the language of place and space. We talk of “spread”, “dispersal” and “distribution”, of “global” pandemics, and, however inaccurately, “The Spanish Flu” and the “China Virus”. Indeed, “The Plague of Athens” 430 BC is often cited as the earliest recorded epidemic (item 1). Our view of disease can appear decidedly geographic. The word “pandemic”, however, also has Greek origins, and comes from “Pan”, meaning “all” and “Demos”, meaning “people”. This points the finger in an altogether different direction. Whilst maps and data visualization can help us to track and understand disease, it is the actions of people that determine its cause, its dissemination, and its cure.
The first attempt to chart the global distribution of all major infectious diseases
That human agency is intricately bound up with the spread of infection was not lost on Friedrich Schnürrer, the maker of “the most important map in the history of mapping world disease patterns” (Altonen). (item 2)
Schnürrer (1784-1833) a physician at the University of Tübingen, published extensively on the subject of infectious diseases, such as, the plague, cholera, and yellow fever. The first cholera pandemic ravaged the world in 1817. In 1827, he published this map.
“In his paper accompanying the presentation of the map, Schnürrer discussed a variety of methodological problems inherent to his project. He objected to the notion that diseases exist independently of their human hosts and paid considerable attention to the difficulties of graphically representing topographical, historical, and scholarly information” (Brömer, p. 179)
The distribution that is reflected on the map, elucidates Schnürrer’s belief that: “health and disease were consequences of man and his place on the earth’s surface, and that as man’s place on earth and activities changed over time, so too did the disease types that came to exist on earth, due to the ways in which the environment is modified over time.” (Altonen)
Catalyzed by the current pandemic and humanity’s continued exploitation of the natural world, this belief has gained many new adherents over the past year.
The First Epidemiological Maps
The first true epidemiological maps were published in a report on the 1832 cholera outbreak in Paris (item 3). This map of Paris by Charles Picquet (1771-1827), has the city divided into 48 districts represented by colour gradient according to the percentage of deaths from cholera per 1000 inhabitants, and, as such, is the first geospatial information system is documented on a map. This revolutionary piece of cartography would not only change the way statistics were used, but would alter the urban landscape of Paris under the hygienist policies of Baron Hausmann.
The map and the report were successfully used by the French government to understand the spread and cause of the cholera epidemic which ravaged Europe in the 1830s. In total, 100,000 people died across France, and 20,000 of those in Paris. Heinrich Heine famously recorded a society masked ball where one of the harlequins suddenly stopped dancing, pulled off his mask and revealed a blue-tinged face (an early symptom), guests subsequently died of the “blue death” and were buried still in their costumes. The epidemic was hard to control because cholera baffled contemporary doctors, most of whom believed that it was a disease spread by unhealthy “miasmas”. Symptoms could appear gradually or in just a few hours; on one side of a street every house might be affected while the other side remained unharmed.
John Snow and the Broad Street Pump
The most famous of all epidemiological maps, and a classic of cartographic data visualization, appears in the work of John Snow (item 4).
In a brief unillustrated pamphlet of 1849, Snow first voiced his theory that cholera is an infectious disease of the alimentary canal and is transmitted through the ingestion of faecal matter from infected patients, mainly through contaminated water. Snow provided evidence for his theory by correlating data on a large number of cholera outbreaks with information on their local water supplies.
In the second edition, which contains the famous map, he showed the Broad Street district of Soho infested with black coffin-shaped bars symbolizing each cholera victim. It is the first use of a spot map in epidemiology. Within a few hundred yards of the Broad Street water pump, some five hundred fatal cases occurred in ten days. Snow found that a sewer pipe passed within a few feet of the well, and his belief that contaminated water was the source of infection was vindicated when he persuaded the parish councillors to remove the pump handle.
Taking the water
Following Snow’s work there was a growing public concern with the water supply, and the London (Watford) Spring-Water Company was set up in 1850 to take advantage of this (item 5). They commissioned a report from two scientists on the water from the Thames, above Teddington Lock (where the capital’s other companies took their water from) and water from Watford Springs, showing that the latter was as “free from organic matter as any water can be in its natural state” (Jones). They aimed not only to improve the quality of water in the capital but also to break the monopolies held by water companies who were providing water from the Thames at high prices.
You know nothing John Snow
Although Snow’s work is now seen as one of the foundation stones of epidemiology, its argument – that cholera as a waterborne disease – was not widely held by the Victorian medical establishment, with prominent people such as Edwin Chadwick, head of the first General Board of Health, expounding the view that the cholera was an airborne disease, bought about by foul odours caused by unsanitary conditions. Although Snow was to prove, that the airborne hypothesis was erroneous, the “miasmatic” theory, with its insistence that “all smell is disease”, would be the catalyst for many of the great municipal sanitary improvements – such as Bazalgette’s great sewer – carried out during the Victorian era.
The map accompanying the General Board of Health’s Report on the Cholera Epidemic of 1854 shown here (item 6), clearly illustrates the authors’ varying approach to the epidemic. Snow’s map is narrowly focused on the centre of the outbreak, and marks only the individual deaths, together with the position of the water pumps; Snow clearly wanting the viewer to draw the causal link between the Broad Street pump, and its proximity to a large number of cholera deaths. The Board of Health’s map, on the other hand, shows a much great area and contains much more information (sewers, drains, plague pits etc.), Snow’s correlation is lost under a mass of miasmic information.
Dr Acland, fellow of the Royal College of Physicians, physician to the Radcliffe Infirmary would record 317 cases of cholera in Oxford during the epidemic of 1856, the third within 25 years (item 7).
C. Stekoulis’s report on the cholera outbreak in 1881 shows the pilgrim routes through Arabia, with caravan routes from Damascus (Syria), Cairo (Egypt), Hillah (Iraq), Hail (Saudi Arabia), Uquair (Saudi Arabia), and Sana’a (Yemen). Other place names include Abu-debi (Abu Dhabi), Chardja (Sharjah), and el Ola (Al Ula). Several of the place names bear manuscript transliterations in Arabic, most notably to Riyadh (item 8).
The contents of Stekoulis work first appeared in the ‘Gazette medicale d’orient’. Concerned at the recent outbreak of cholera in Arabia, Stekoulis considers both the causes of the outbreak and the possible threat this poses to Europe, as well as suggesting methods of containing the plague. His information is based on that supplied to him by Muslim colleagues at the International Council of Health in Constantinople.
Cholera was first recorded in Jessore, Bengal, near Kolkata, in 1817. The local conditions were ideal for the epidemic, as the region was densely populated, with a moist, tropical climate, while sanitary conditions were often lax. Cholera lingered around Calcutta constantly throughout the rest of nineteenth century, occasionally spiking into severe outbreaks. The year 1887 was not an especially bad year for cholera in Calcutta, although, as the map shows, the ‘normal’ situation was still quite grim. A note to the bottom right of the plan states: “cholera deaths occurring in the Hospitals excluded”; their inclusion would have obviously skewed the overall picture, of the disease generally even spread throughout the city. Kolkata’s medical department worked ceaselessly to stamp out the disease, but did not make transformative headway until the early twentieth century (item 9).
This extremely rare map depicts the spread of the Russian Cholera Epidemic of 1892 (item 10), which officially claimed 267,800 lives. The map is one of only a handful of Cholera maps to have been printed entirely in Russian Cyrillic, and was lithographed in St. Petersburg not long after the outbreak by C. de Castelli.
The map embraces the western two-thirds of the Russian Empire, extending eastward just past Lake Baikal. The Russian Cholera Epidemic of 1892 was part of the Fifth International Cholera Pandemic (1881-96), and as shown here by a series of red arrows, the epidemic first entered Russian territory from Persia. From there it travelled across the Caspian Sea, through the Caucuses and then up north-westwards across the Steppes to infect Kiev, Moscow, St. Petersburg and Warsaw. Next, the epidemic wheeled eastwards, travelling across Siberia, almost as far as Irkutsk.
Russia was especially vulnerable to Cholera due to the great poverty and low hygienic standards of many of its rural areas and urban slums. Moreover, the Tsarist regime’s implementation of health standards and medical systems was irregular and often not well coordinated. Russia had also suffered greatly during both the Third (1852-60) and Fourth (1863-75) International Cholera Pandemics.
The horrendous catastrophe motivated the Russian authorities to call a Cholera Conference, held in St. Petersburg in December 1892, during which new medical regimes were agreed. Nevertheless, the epidemic in Russia continued into 1893, killing a further 30,000 people.
These outbreaks correlated with increased travel and emigration as evidenced by the beautiful simplicity of the maps of Charles Joseph Minard (1781-1870) (item 11).
It has been estimated that, since the beginning of the nineteenth century, cholera has been responsible for some 50 million deaths, and although relatively simple rehydration treatments are now readily available, according to the World Health Organisation some 120,000 people a year still die from the disease.
Malaria was the second biggest killer in colonial India after cholera; from 1800 to 1921, an estimated 20 million people died of the disease.
Although malaria was already endemic in India, the nineteenth century saw a dramatic spread of the disease. A key cause was the establishment by the British government of a railway system, and an irrigation and canal network, without providing adequate drainage systems to combat floods and excess rainfall. The lack of drainage created stagnant water in which mosquitoes could breed. The high death rate, the resulting economic effects and the risk to the lives of British officers serving in vulnerable areas like the Punjab, encouraged new research on malaria control. In the 1840s, attention was paid to proper drainage and chemoprophylaxis was started with quinine. The colonial government would get through some nine tons of the drug annually by the 1850s. This map was produced around 1880, most probably under the auspices of the Public Health Commissioner of India, which had been established in 1869 (item 12).
The map is just one of many attempts made by the British in India to gain a better understanding of the spread and cause of the disease towards the end of the nineteenth century. At about the time the map was produced, Surgeon Major Sir Ronald Ross joined the Indian Medical Service. In August 1897, he demonstrated the life cycle of the malarial parasite, and showed that anopheles mosquitoes carried the protozoan parasites called “plasmodia”. He was later knighted and given a Nobel Prize in Medicine in 1902. This discovery changed malaria research and focused malaria control programs on the eradication of mosquitoes.
The Plague of Hong Kong (item 13).
A mysterious plague arrived in Hong Kong via Canton, where the outbreak began in January of 1894, likely from transmission through the Indian trade routes. Hong Kong was officially declared an infected port on May 10th 1894, and by July the colony already suffered 2442 deaths. Hospitals were overflowing with infected patients and panic was widespread and rampant – Sir William Robinson lamented, “without exaggeration, I may assert that, so far as trade and commerce are concerned the plague has assume the importance of an unexampled calamity”. Between May and October of that year, more than 2,000 people died from the plague and a third of the population fled Hong Kong.
As the months passed and the weather grew cooler, the plague abated, but it returned almost every year taking thousands of lives between February and March before virtually disappearing in the autumn. The root cause of the plague eluded scientists and government officials, despite efforts to eradicate the disease from the colony. Suspicious that unsanitary living conditions were to blame, the government ordered house to house inspections and thorough disinfection.
Dr. Gomes da Silva, the Principal Medical Officer at the Portuguese colony of Macau identified weather patterns as having an influence on the outbreak of the plague, which riddled Macau in 1895. When the conditions in the summer were dry, the disease seemed to flourish, whereas early and abundant summer rain lessened the severity of the plague. He got one step closer to the answer by noting that the disease seemed to attack “only Chinese… and rats”.
2325 years after the “Plague of Athens”, it is likely that the same disease morphed into the “Plague of Hong Kong”. In 1905, the mystery of the plague’s origin was solved. The Plague Research Commission of India in Bombay determined that the bacillus, Pasteurella pestis, came into the human bloodstream through flea bites which were carried by rats. With house refuse in Hong Kong thrown into the street, coupled with a lack of rain to clear it away, the rats thrived and so did the fleas. When the fleas decimated the rat population, they moved onto bigger victims – humans. It was the actions of these bigger victims, not some accident of geography, that had created the circumstances for the spread of infection.