Published online by Cambridge University Press: 15 May 2009
In previous studies of the bacterial flora of the upper respiratory tract and its variations during attacks of acute coryza (Hoyle, 1932), it was found that there was in many cases a striking relationship between the appearance of certain organisms with definite pathogenic properties towards the lower animals, in the upper respiratory tract, and the occurrence of acute infections. This relationship was especially marked in the case of the influenza bacillus, and it was suggested that this organism played a prominent part in the aetiology of upper respiratory infections. The significance of the influenza bacillus in acute coryza has been noted by various workers (Noble, Fisher and Brainard, 1928; Burky and Smillie, 1929; Webster and Clow, 1932; Kneeland and Dawes, 1932), but on the other hand various observers have found the incidence of influenza bacilli in the respiratory tract to be the same in normal health and in acute coryza, and Fleming (1929) and Fleming and Maclean (1930) have devised a technique by means of which they claim to have isolated influenza bacilli in 100 per cent, of normal throats. One possible explanation of these conflicting results may be found in the absence of any very exact criterion of what constitutes a typical influenza bacillus.