Pandemic: Tracking Contagions, from Cholera to Coronaviruses and Beyond

by Sonia Shah

John Snow was particularly well placed to grasp the shortcomings of the miasma theory as applied to cholera. Snow had been knocking himself unconscious with various gases—ether, chloroform, and benzene, among others—for years, studying their effects on his body in search of the perfect anesthetic to administer to his patients.13 As an expert on the behavior of gases,

the disease would affect the respiratory system, including the lungs, much like a deep breath of acrid smoke. And yet, it didn’t. Instead, cholera plagued the digestive system.

Nineteenth-century treatments for cholera increased its death toll from 50 to 70 percent.22 Since they considered cholera patients’ vomiting and diarrhea therapeutic, doctors treated patients with compounds that intensified the very symptoms that were killing them. They administered the toxic mercury compound mercurous chloride, or “calomel,” which induced vomiting and diarrhea.

all signs that physicians today would recognize as mercury toxicity.25

Hippocratic medicine, in other words, was a boon to Vibrio cholerae.

It explained health and disease more effectively than the earlier ideas—that health and disease were the work of the gods

“To be accepted as a paradigm, a theory must seem better than its competitors, but it need not, and in fact never does, explain all the facts with which it can be confronted.”

And it was able to maintain an illusion of success.

There was no point in grouping them together and comparing their outcomes. If, in general, patients treated with mercury fared poorly compared to patients treated with other remedies,

To prove that the bacteria didn’t cause cholera, Pettenkofer and his allies devised a daring demonstration. Pettenkofer procured from a patient dying of cholera a vial of stool, teeming with hundreds of millions of vibrios, and drank it.