Viruses of the upper respiratory tract.

Abstract

The influence of tissue culture techniques, especially the serial propaga­ tion of various cell lines in vitro as suspended cell cultures, upon our knowl­ edge in the field of infectious diseases and in particular virology, promises to be comparable to the development of semisolid media for the propagation of bacteria. Just as the latter innovation ushered in a period of great atten­ tion to etiologic identification, laboratory diagnosis, and taxonomy of bac­ teria, the use of tissue cultures has already provided a glimpse of a similar prospective era for viral diseases. In this context the subject of viruses of the upper respiratory tract is appropriate for review. Such a title is noncom­ mital regarding the question of the pathologic importance of any particular virus recovered by these ne'w techniques, although commendable epidemio­ logical studies which relate some of the newly recognized viruses to disease entities already have been performed. Neither can this review discuss with any completeness all of the known viruses for which the respiratory tract may serve as a portal of entry, but an attempt will be made to examine the recent contributions to our knowledge of common upper respiratory ill­ nesses and those viruses for which the upper respiratory tract appears to be the principal habitat. Where viral agents have not been cultivated success­ fully from patients with respiratory diseases that are presumed to have a viral etiology, recent clinical observations will be reported. Although the number of such publications is meager compared to those concerned with the laboratory aspects of viruses from the upper respiratory tract, it must be emphasized that the majority of common upper respiratory illnesses still must be classified upon the basis of clinical observations and epidemiology. Also, the broad application of laboratory procedures that deal with the pres­ ently known viruses is not yet practical. Repetition of material discussed in the comprehensive review of viral diseases by T. F. McNair Scott in the Annual Review of Medicine, vol. 6, May, 1955 (1) will be avoided except to supplement and enlarge upon certain aspects related to respiratory diseases. Also, in agreement with the advice to reviewers of scientific literature re­ corded by Arnon (2), only material that has been published or presented will be noted. There is an inevitable lag in such communications and the author knows of additional reports of recent and continuing research upon the common respiratory diseases that can be expected to.appear in the near fu­ ture. It is hoped, therefore, that this review will serve the reader by enabling him to iiltegrate some of the current information with past and future publications. .