Walking into a cholera epidemic

PUBHLTH 405
Social Epidemiology of Infectious Disease
University of Michigan School of Public Health

Jon Zelner
[email protected]
epibayes.io

An opening question

What was most surprising, powerful, or interesting to you when reading the first chapters of The Ghost Map?

Agenda

  • A brief introduction to Cholera. (10m)

  • Digesting the first chapters of The Ghost Map. (30m)

  • Identifying the relevant levels of disease for your project pathogen (in groups) (30m)

  • Wrapping up (5m)

A brief introduction to V. Cholerae

Cholera is transmitted via the fecal-oral pathway

Cholera transmission happens as part of a complex social-ecological web

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 my 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. (Johnson 2007, 15)

A 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

  • Who was Henry Whitehead and what do we gain from following him around the Golden Square neighborhood of London?

  • 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?

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)

Rapid population growth pushed the infrastructure of London past its limits

As the population grew, so did the connectivity of the physical environment

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. (Johnson 2007, 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. (Johnson 2007, 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. (Johnson 2007, 12)

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

Contamination Dossiers

What am I looking for?

  • Diverse, comprehensive, and reliable sources.

  • Good match between source type and the purpose you are using it for.

  • Summaries/syntheses of the literature on your pathogen.

ChatGPT and other AI-ish tools have limited - but potentially helpful - uses in the research process.

“Here is a humorous image representing the process of researching and summarizing sources for a project on the social history of infectious diseases. Let me know if you need any changes or additional elements!”

They bring sources together in a way that homogenizes them and may miss important detail & nuance

“Here is the updated image featuring a college student researching the social history of infectious diseases.”

Keeping your sources organized

I highly recommend using a reference manager like Zotero to keep your sources organized, easy to share, and easy to cite

Returning to the Levels of Disease

  • Going to spend some time identifying the relevant levels of disease for your project pathogens.

  • Specifically, I am asking you to identify concrete examples for each of the levels in the original CDC guidelines.

  • These include: cluster, outbreak, epidemic, endemic and pandemic.

  • If an example doesn’t exist, that is fine, just explicitly note it.

Next Time

Miasma vs. Germ Theory

References

Johnson, Steven. 2007. 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.