Walking into a Cholera epidemic

EPID 684
Spatial Epidemiology
University of Michigan School of Public Health

Jon Zelner
[email protected]
epibayes.io

Agenda

A brief introduction to Cholera. (10m)
Digesting the first chapters of The Ghost Map. (30m)
Smoothing hands-on

A brief introduction to V. Cholerae

Cholera is transmitted via the fecal-oral pathway

Rice water stool characteristic of Cholera infection

What makes this so deadly?

Cholera remains an important cause of global morbidity and mortality

Approximately 2.5M annual cases, 95K deaths

In the present day, Cholera often appears in the aftermath of disasters

We are currently living through the seventh global cholera pandemic

Global dissemination of current pandemic strain as of 2016

The Ghost Map

Johnson summarizes one of my key goals for this class perfectly

The history of knowledge conventionally focuses on breakthrough ideas and conceptual leaps. But the blind spots on the map, the dark continents of error and prejudice, carry their own mystery as well. How could so many intelligent people be so grievously wrong for such an extended period of time? How could they ignore so much overwhelming evidence that contradicted their most basic theories? These questions, too, deserve their own discipline — the sociology of error. (1, p.15)

Another quote I love from The Ghost Map

“Most world-historic events - great military battles, political revolutions - are self-consciously historic to the participants living through them. They act knowing that their decisions will be chronicled and dissected for decades or centuries to come. But epidemics create a kind of history from below: they can be world-changing, but the participants are almost inevitably ordinary folk, following their established routines, not thinking for a second about how their actions will be recorded for posterity.” (From The Ghost Map, p. 32)

Stepping into Golden Square

What social and environmental factors made 1850s London an ideal environment for Cholera transmission?
What global 🌍 changes impacted London’s Cholera risk in the 19th century?
How did urbanization impact the evolution of V. Cholerae?
What struck you most in these first couple of chapters?

Human waste was an unavoidable fact of life in Victorian London

Victorian London had its postcard wonders, to be sure—the Crystal Palace, Trafalgar Square, the new additions to Westminster Palace. But it also had wonders of a different order, no less remarkable: artificial ponds of raw sewage, dung heaps the size of houses. (1, p.11)

Not all innovations push public health forward

Water closets were a tremendous breakthrough as far as quality of life was concerned, but they had a disastrous effect on the city’s sewage problem. Without a functioning sewer system to connect to, most WCs simply flushed their contents into existing cesspools, greatly increasing their tendency to overflow. (1, p.12)

A fancy-looking ‘washout’ water closet from thw 1850s

Our explanations for epidemics have huge consequences

No one died of stench in Victorian London. But tens of thousands died because the fear of stench blinded them to the true perils of the city, and drove them to implement a series of wrongheaded reforms that only made the crisis worse. (1, p.12)

Cartoon rendering of the stink - or miasma - as death ☠️

Urbanization closed the loop of the 💩 \(\to\) 🚰 cycle

“What the Vibrio cholerae bacterium desires, more than anything, is an environment in which human beings have a regular habit of eating other people’s excrement.” (p.40)

Next Time

Miasma vs. Germ Theory

References

Johnson S. The Ghost Map: The Story of London’s Most Terrifying Epidemic–and How It Changed Science, Cities, and the Modern World. Reprint edition. London: Riverhead Books; 2007.