BLUE DEATH IN BENGAL - Tambora: The Eruption that Changed the World - page 47

Jameson's meteorological emphasis in favor of an emerging liberal paradigm that captured
the imaginations of progressive physicians and public officials through the Victorian age. In-
fectious disease was not “natural” but rather the product of human-created filth, of the open
sewers and fetid air of slums and industrial tenements. Cholera was a social disease, an index
of failures by nation-states to regulate and sanitize their colonial ports of trade and booming
industrialized cities. In the pulpits of Europe, the cholera would accordingly change shape
from a divine punishment for wickedness to a progressive moral calling for social reform, to
provide hygienic living conditions for the newly urbanized masses.
Thus the early climatological theories of cholera rapidly lost ground during the heroic age
of nineteenth-century sanitarianism. For almost a century after the apparently definitive dis-
covery of the comma-tailed cholera bacterium in a Calcutta pond by pioneer bacteriologist
Robert Koch in 1883, both clinical theory and public health policy surrounding the disease
endorsed the emerging contagionist consensus, focusing on its human-to-human transmission.
The fecal matter of infected persons in waterways was simply the pathogen's mode of
transit from one human host to another, which might be denied by proper investment in
sanitary engineering. This dominant model of twentieth-century cholera science relegated
Jameson—and a host of other pre-Victorian writers in the medico-meteorological tradi-
tion—to the dustbin of history, as embarrassing examples of the puffed-up guesswork and
shamanistic fantasies that passed for medical science before the discovery of bacterial infec-
tion. Jameson's enlightenment medical geography, with its environmentalist perspective on
disease transmission, had lost the battle of ideas, which resolved by century's end into a nar-
rower medical-scientific practice focused on the career of pathogens, to be charted by the
new techniques of laboratory biology.
Now, however, at the beginning of the twenty-first century, the medico-meteorological
worldview of James Jameson has experienced a second coming. The post-Victorian bac-
teriological consensus on cholera has been overtaken by a new, more complex etiological
paradigm that restores credibility to the early nineteenth-century model of climatic disease
dynamics. Beginning in the late 1960s, epidemiologists utilizing the tools of modern molecu-
lar biology discovered the vibrio cholerae thriving in nonendemic form among the zooplank-
ton and protozoa of a wide range of aquatic environments—from the Chesapeake Bay to the
lochs of Scotland—independent of human hosts. Not the “Asiatic” cholera after all! Nor are
humans the end point or object of the cholera. We are merely accidental part-time hosts to a
pathogen that enjoys ancient privileges in a range of aquasystems outside the human intest-
ine. From its ancestral origins in the deep sea, the v. cholerae resides year-round in brackish
reservoirs around the globe, while its pathogenic strains are favored only within dense human
communities situated at low elevation along estuarine coasts, in tropical climates character-
ized by high temperatures, humidity, and heavy seasonal rain. 25
To succeed in this global role, the cholera bacterium possesses an unusually flexible and
adaptive genetic structure highly sensitive to changes in its aquatic environment. In the mon-
soonal waters into which the five major rivers of the Ganges delta flow, the vibrio cholerae
prospers by attachment to benign organic hosts—plankton, algae, crustaceans, and even tiny
insects—where they participate in the mineralization of matter vital for the replenishment of
the aquatic food web. The circulation patterns and organic life cycles of the northern Indian
Ocean are unique on account of the monsoonal climatic regime. Over the Bay of Bengal in
June and July, the water vapor content of the atmosphere reaches its highest level anywhere