Vibrio cholerae was once a species of marine bacteria attached to some plankton in the coastal wetlands of the Bay of Bengal. In grim detail, science journalist Shah (The Fever: How Malaria Has Ruled Humankind for 500,000 Years, 2010, etc.) demonstrates how it became the global source of horrendous deaths and how the story of cholera is paradigmatic of how pandemics happen.
Cholera emerged in the early 1800s after the East India Company began to fill in and settle the wetlands. Disease might occur if a fisherman swallowed some brackish water, a direct transmission from the vibrio to a human. But to make the jump to human-to-human transmission, the vibrio changed. It adapted ways to form colonies, making it harder to dislodge from the human gut, and it developed a toxin that flushes all the fluids from the body, causing death by dehydration. Still, cholera might have stayed local except for other 19th-century developments: steamships and newly dug canals and waterways moved goods and people rapidly across land and sea, creating new waves of infection while also swelling the populations of cities, which lacked clean drinking water and proper waste disposal. By the 1830s, cholera was devastating Paris, London, and New York, exacerbated by the arrogance of medical elites who swore by the miasma theory of disease. Then, add political corruption after the cause was known: city contractors asked to supply clean water but substituting foul; government officials who would deny the existence of disease, so as not to discourage business. The ingredients for pandemics remain potent in a jet age with deforested lands, ever growing cities, the consumption of bush meat and other exotic wild cuisine (from illegal “wet markets”), antibiotic resistance, inadequate disease surveillance, and destructive cultural attitudes, ranging from abject fear to blame to indifference. Shah covers all of these aspects in vivid prose and through revealing eyewitness accounts.
This is not fun reading, but it’s necessary—one can only hope that it drives more effective surveillance and rapid response to tomorrow’s plagues.