Contingent contagionism

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Contingent contagionism was a concept in 19th-century medical writing and

germ theory, used as a qualified way of rejecting the application of the term "contagious disease" for a particular infection. For example, it could be stated that cholera, or typhus, was not contagious in a "healthy atmosphere", but might be contagious in an "impure atmosphere".[1] Contingent contagionism covered a wide range of views between "contagionist", and "anti-contagionist" such as held by supporters of the miasma theory.[2]

Background

A form of contingent contagionism was standard in medieval European medicine.

Contagion was not conceptualised as restricted to physical contact. A corruption of air could be transmitted from person to person, at short range.[3]

Contagionists versus anticontagionists

By the 1840s

cholera pandemic). The latter opposed quarantines. Anticontagionists, for example, argued that infection could be at a distance, from a cause that could be sporadic and possible diffused through the air, and taking advantage of "predisposed" individuals.[4] Public health measures quite typically combined contagionist and anti-contagionist aspects.[5] Anti-contagionists, such as Florence Nightingale who was a convinced miasmatist, could collaborate with contingent contagionists on sanitary measures.[6]

The "filth theory"

Decomposing organic waste, as "filth", was considered implicated in many diseases, because of the gases it generated. The application of contingent contagionism could be that there was a contagious agent that was spread by filthy conditions. Sanitation as cleaning was therefore directly associated with public health.[7] It has been commented that those involved in public health at this time, successful in bringing down death rates, "often attributed disease causation to levels farther up the causal chain than direct biological mechanisms".[8]

Ventilation

The Medico-chirurgical Review in 1824 wrote that it had "always advocated" the doctrine of contingent contagion in the case of yellow fever "and indeed in most fevers". Having mentioned William Pym (contagionist) and Edward Nathaniel Bancroft (anti-contagionist) as extremists, it went on to say (italics in the original)

That the yellow fever of the West Indies [...] is rarely contagious, under common circumstances of cleanliness and ventilation, is as well ascertained as any fact in medicine.[9]

Which it qualified in terms of overcrowding, and an outbreak in 1823 on the sloop HMS Bann.

The influence of atmosphere on contagion was subject to a distinction: a "pure" atmosphere might effectively block airborne contagion, while an "impure" atmosphere was ineffective for that; or on the other hand "impure" atmosphere, as well as crowding and filth, might mean a disease could "acquire" the property of contagion.

aetiology of the middle of the 19th century. Inadequate ventilation was one factor to which the consensus pointed.[11]

Zymotic theory

Zymotic theory was an explanation of disease developed by Justus von Liebig and William Farr in the 1840s. A form of contingent contagionism, it began with a hypothesis on decomposition of large complex molecules, depending on collision with other such molecules. It relied on fermentation as an underlying analogy for disease.[12]

Notes

  1. ^ Charles Brodhead Coventry (1849). Epidemic Cholera: Its History, Causes, Pathology, and Treatment. Geo. H. Derby & Company. p. 51. Retrieved 21 June 2013.
  2. PMID 12435761
    .
  3. ^ Irina Metzler, Disability in Medieval Europe (2006) (PDF) Archived 2013-07-17 at the Wayback Machine, at p. 71.
  4. . Retrieved 21 June 2013.
  5. ^ ocp.hul.harvard.edu, Cholera Epidemics in the 19th Century.
  6. ^ Sandra Holton, Feminine Authority and Social Order: Florence Nightingale's Conception of Nursing and Health Care, Social Analysis: The International Journal of Social and Cultural Practice No. 15, Gender and Social Life (August 1984), pp. 59-72, at p. 60. Published by: Berghahn Books. Stable URL: https://www.jstor.org/stable/23169278
  7. . Retrieved 21 June 2013.
  8. . Retrieved 21 June 2013.
  9. . Retrieved 21 June 2013.
  10. ^ René La Roche (1855). Yellow Fever, Considered in Its Historical, Pathological, Etiological, and Therapeutical Relations: Including a Sketch of the Disease as it Has Occurred in Philadelphia from 1699 to 1854, with an Examination of the Connections Between it and the Fevers Known Under the Same Name in Other Parts of Temperate, as Well as in Tropical, Regions. Blanchard and Lea. p. 566. Retrieved 21 June 2013.
  11. . Retrieved 21 June 2013.
  12. . Retrieved 21 June 2013.