The nature and control of yellow fever / by Harald Seidelin.

  • Seidelin, Harald.
Date:
1913]
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Licence: Public Domain Mark

Credit: The nature and control of yellow fever / by Harald Seidelin. Source: Wellcome Collection.

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    THE NATURE AND CONTROL OF YELLOW FEVER (Read at the XV International Congress on Hygiene and Demography, Washington, September 25, 1912.) By HARALD SEIDELIN. A “Yellow fever is an infectious disease, produced by Pavaplasma * flavigenum and transmitted by S. fasczata. The latter state- ' ment has met with universal acceptance, and we may, at “present, take its correctness for granted. But it is worth _ while to examine the rather elaborate structure which has been erected on this foundation. The theory, as it now ‘stands, embraces the following particulars: yellow fever is transmitted by S. fasczata, and by no other means, in particular by no other mosquito. The transmission can only take place after the yellow fever parasite has under- gone a development in the mosquito, the duration of which is, approximately, twelve days. Yellow fever blood is infectious during the first part of the disease, but not after the third day. Transmission is believed to take place at night time only. WHereditary transmission of the yellow fever germ from mosquitos to their offspring, and infection of one mosquito from another, without the intervention of a human host, are generally considered as unproved possi- bilities. Each of these points must be discussed separately. I may state at once that conclusions on these secondary points have not been drawn by the U.S. Army Commission ; Reed and his fellow-workers were very careful in their statements; but the assertions of later, less-cautious, observers have so often been repeated that they are now almost universally believed. The axiom that yellow fever is transmitted by no other mosquito than S. fasciata is an assertion entirely without - proof - it is, nevertheless, repeated in most text-books, and even in special literature dealing with yellow fever. The conclusion drawn by a recent author (Doerr), not himself ‘a worker on yellow fever, that the yellow fever virus must be intimately adapted to a certain mosquito-species, as experi-
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