Warren T. Vaughan wrote in 1920:
Following every widespread epidemic or pandemic of influenza, the contemporary literature becomes virtually flooded with reports of scientific studies on the etiology and the epidemiology of the disease. By the time that recrudescences have ceased, interest has usually lagged and eventually research in this subject has practically ceased, only to be revived with the development of the next extensive epidemic. To one who has had occasion to review the extensive literature of the last pandemic, it becomes apparent that many of the recent writers are uninformed, or at best only partially informed, regarding the rather extensive information accumulated during the 1889 epidemic.
The longer one studies the observations made in 1889-93 the more firmly convinced one becomes that the recent pandemic was identical with the former in practically all of its manifestations. It is desirable that, following each epidemic prevalence some individual or individuals review the literature of the preceding epidemics, acquaint himself with what has been written regarding influenza in the intervening time up to the epidemic prevalence and correlate the work done in these two periods with the various reports regarding the latest epidemic.
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