Pox_ An American History - Michael Willrich [15]
Wyman’s officers in the Marine-Hospital Service disseminated the “Précis” widely, especially in the South. The report reflected state-of-the-art American medical knowledge about smallpox. Wyman’s description of the clinical course of smallpox squares with descriptions of the disease found in medical treatises and journals from the period, as well as the accounts of local cases written by physicians such as Dr. Henry Long. The vast scientific literature on smallpox produced since that time has generally confirmed that clinical picture, while shedding new light on the virological and pathological processes that underlay the disease. Unlike the vast majority of physicians alive today, these turn-of-the-century experts had firsthand experience with smallpox. For them smallpox was not a frozen stockpile preserved, like ancient DNA sealed in amber, in a carefully guarded government laboratory vault and read about in medical journals. For them small-pox was still a part of the known world.30
Perhaps the most significant misunderstanding about smallpox shared by the authors of the “Précis” and many of their scientific contemporaries had to do with the mechanics of disease transmission. They understood correctly that smallpox could be spread by the passage of “the microbe” from one person’s respiratory system to another’s. In fact, a person suffering from smallpox shed virions in each droplet of saliva. A single breath, cough, laugh, sigh, or spoken word was enough to launch the virions into the air. When one or more particles touched down upon the mucous membrane of another person’s mouth, nose, throat, or lungs, the process of viral replication began within hours.
Where the “Précis” went wrong was in its insistence that such face-to-face contacts constituted a lesser threat than did the scabs and crusts of dried pus that fell from the skin of a convalescent patient. “The contagion is tenacious,” the “Précis” stated, “and may be conveyed by persons and by fomites, such as hair, clothing, paper, letters, furniture, etc., or it may be spread through the air by means of the wind blowing the dust containing the virus.” This belief in the infectious power of “fomites,” contaminated objects of countless variety, led to the conclusion that smallpox was what nineteenth-century sanitarians called a “filth disease”—dangerous to all but spread chiefly by the lower orders. As the “Précis” put it, smallpox was “more common among the colored races, probably on account of their condition of living in small, crowded rooms, with slight regard for cleanliness.”31
The “Précis” got the infective nature of variola about half-right. The crowded sleeping quarters that the world’s poorest people called home—be it a sharecropping family’s one-room cabin or a bamboo hut—were prime variola territory. It surprised no one when, two weeks after Harvey Perkins shared a hut with two other workers at Neal’s Camp, reports reached Charlotte that two cases of smallpox had broken out in the encampment. There were obvious obstacles to maintaining personal hygiene and health under such circumstances. Still, scientists now believe that “filth” had little to do with the spread of smallpox. Laboratory tests have shown that the virions in smallpox scabs can, under optimal conditions, retain their infectivity for years. But the virions are so tightly bound within the hard fibrin mesh of the scab that it takes heavy grinding to release them. For this reason, many experts have concluded that fomites were “relatively unimportant” transmitters of infection, compared