Imaging Illness
The “Saint of Spitalfields,” Rev. Tobias Atwater, is found stabbed to death, his body mutilated and jammed into a sewer pipe, a popped balloon in his waistcoat pocket.
Days later Sir Maxwell Ball, chairman of the East London Waterworks Co., is found stabbed to death in an iron “slipper bath” tub in the Whitechapel Bathhouse, a popped balloon in his waistcoat pocket.
These are the first of a series of murder victims who were associated with London’s cholera epidemic in 1849: Some of them mishandled the spread of disease by releasing unfiltered water into the drinking water supply; others preyed upon the poor whose families were dislocated because of the epidemic.
It is November, 1866, nearly 20 years after the worst outbreak of cholera in London history that took more than 14,000 lives. The Inspector of Nuisances rushes feverish parents to what’s known as the fever hospital, sends children to the Whitechapel Workhouse where they pick oakum for long hours during the day and suffer under the hands of abusers at night.
This is the setting for Murder by Lamplight, the 2024 murder mystery by Patrice McDonough that dramatizes London’s delayed response to cholera and public health officials’ reluctance to acknowledge the source of the epidemic, persisting in the belief that the disease spread through the air despite carefully gathered evidence that traced the path of infection via the water supply.
https://www.amazon.com/Murder-Lamplight-Patrice-McDonough-ebook/dp/B0C6FW2HCM
For this author’s review, see: https://historicalnovelsociety.org/reviews/murder-by-lamplight-a-dr-julia-lewis-mystery/
The novel refers to the work of Dr. John Snow, who created a mortality map or what was known at the time as The Ghost Map in 1854. The map was one of the first, if not the first, scientific image to demonstrate how contagion spreads. It makes use of the principles of epidemiology that as recently as the Covid-19 pandemic of 2020 have been used to survey communities where disease occurs, identify vulnerable areas and populations, and begin to understand how disease spreads and what may be done to slow it down.
Ghost Mapper
https://www.londonremembers.com/subjects/dr-john-snow
Dr. John Snow first became aware of cholera when he was a physician-in-training and was sent to treat miners who were dying of the disease in Killingworth, northern England. At the time, he noted the link between unsanitary conditions and disease, telling his family that the mine “was one huge privy,” and he suspected the cause of the epidemic could be found in food or water. Cholera resided in and affected the digestive system, and as Snow observed in Killingworth, miners “always take their victuals with unwashed hands.” (Marilee Peters: Patient Zero)
After finishing his medical training, Snow established a medical practice in London where he specialized in anesthesiology, experimenting with various doses of ether and chloroform on animals as well as himself in his home. (Ghost Map)
Snow began focusing on cholera and its mechanism of transmission in 1848 when he learned of a peculiarity—two men had died from the disease within days of one another after spending the night in the same room of a lodging house. The disease then spread throughout the nearby area over the following week. Snow discounted the miasma theory of cholera transmission that was prevalent at the time—ie, the disease spread through the air—when he learned the same doctor had treated both men in the same room in the lodging house and breathed the same air but never contracted the disease. (Ghost Map)
After consulting with chemists and water and sewer authorities, Snow theorized that cholera was caused by ingesting water or material that had been contaminated by people who had already been infected, and he started gathering evidence to support the theory. He studied the water supply in London’s districts and learned that residents were less likely to die from cholera if their water came from a particular area of the Thames--upstream from where sewage routinely drained into the river. People of northern London got their water from various sources, including rivers other than the Thames. People living in southern London who were more at risk for cholera got their water downstream from the area of the Thames where the city’s sewers discharged their waste. (Ghost Map)
Snow tested his theory by surveying people in their homes, asking who and how many people had been affected by the disease, how many had died, and where they got their drinking water. He soon found irregularities in the water supply system: Though buildings were close by one another, they did not receive water from the same source. One tenement received water from one of the city’s two private water supply companies, while neighboring buildings got water from the other company.
An outbreak of cholera along Broad Street in Soho gave him a unique opportunity—he could take water samples from all the local pumps and try to track patterns of disease contamination.
The Broad Street Epidemic
The first case of cholera along Broad Street was detected on August 31, 1854. By September 10, 500 people were dead from the disease.
Snow walked up and down the streets in the neighborhood and interviewed residents to learn who had contracted the disease and document where they lived and the source of their water. He encountered oddities: None of the workers at the Broad Street Brewery died or even was affected by the disease, but none of the workers drank water from nearby pumps either. They were given rations of beer, and the water used in the brewing process was boiled before entering the tanks. https://www.history.co.uk/articles/1854-broad-street-cholera-outbreak
Likewise, only a few people living in St. James Workhouse, a charity home with more than 500 men, women, and children located around the corner from Broad Street, contracted the disease while hundreds of their neighbors living only a few doors away succumbed. (Patient Zero)
Snow suspected that cholera was being spread via the Broad Street pump but was stymied by one fact: An elderly woman who lived across town and nowhere near the Broad Street pump had died in the epidemic on September 2. Through his interviews, Snow learned that the woman’s sons worked in a percussion cap factory on Broad Street and sent a jug of water drawn from the Broad Street pump to their mother every day because she believed the water tasted better. (Patient Zero)
With these anomalies aside, Snow was able to show that the source of the disease and the epidemic was the Broad Street water pump. The results of his investigations? A map.
The Map
A map of mortality, or what’s known as the Ghost Map, was prepared by Dr. John Snow in the summer of 1854. On a cross section of city streets, Snow marked every case of cholera that had been reported at each address. He then flagged the locations of water pumps in and around Broad Street. The result was clear: Black bars marking every cholera-related death radiated out from the Broad Street pump. The density of the markings was thickest at locations closest to the pump, and it lessened at locations farther away. (Patient Zero)
https://www.slideserve.com/thais/gen-101-public-health-powerpoint-ppt-presentation
Though somewhat skeptical of Snow’s findings, the Board of Governors of the parish overseeing Broad Street voted on September 8 to remove the handle to the pump that supplied water to residents, and the trajectory of the disease turned. Deaths from cholera continued in the area for several more days, but they then declined significantly, and no new cases of the disease were reported. (The Ghost Map)
Mapping Disease Today
Much like John Snow, epidemiologists create maps of disease outbreaks to identify their source and plot their paths. The Covid-19 pandemic was traced to Wuhan, China, at the end of 2019, and its course was illustrated in maps across the globe and in the US.
Present-day maps depend on data similar to that collected by Snow—reports of particular symptom clusters and deaths related to them as well as where they are occurring—and are gathered by means of sophisticated local, regional, and national public health surveillance systems. They also rely on statistical modeling of data that identifies which individuals in the population are susceptible or more likely than others to contract the disease, which are infectious and capable of spreading the disease, and which at one time had the disease but are now no longer infected. (https://doi.org/10.1098/rsfs.2021.0014)
Scientific techniques for tracking disease have been fine-tuned during the Covid pandemic. Among them are geospatial analysis, which tracks the spread of disease over a geographical area over the course of time; data mining, which dives into geographical information systems and finds patterns of disease spread among interstate travelers and mobile device users; web-based mapping, which disseminates information about disease spread for Internet users. https://pmc.ncbi.nlm.nih.gov/articles/PMC7832930/
The objective of today’s disease imaging technologies is the same as John Snow’s: step-by-step accumulation of information from infected individuals about where and how they may have acquired the disease to find the means of transmission, identify and eliminate the source, and take steps to stop the spread.
Sources:
Steven Johnson: The Ghost Map, Riverhead Books, 2006.
Marilee Peters: Patient Zero, Annick Press Ltd., 2021.
https://pmc.ncbi.nlm.nih.gov/articles/PMC7832930/
https://www.history.co.uk/articles/1854-broad-street-cholera-outbreak