The Etiology of Common Colds

Abstract

however, that the number of bacteria found is relatively small and that the experimental lesions in the ovary are not due to an overwhelming growth, it is clear that while excision and resection of ovaries is indicated in some instances, it should no longer be done without due regard to the existence of chronic foci of infec¬ tion which may serve not only as the place of entrance but also as the place for the bacteria to acquire the peculiar properties necessary to infect the ovary.There is little indication for the removal of this type of ovary with the idea that it may play the rôle of a secondary focus of infection, yet Case 2 indicates that this at times is possible. The results suggest, how¬ ever, that the eradication of primary foci of infection early in this type of patient might in some cases pre¬ vent the premature sclerotic degeneration of the ovary. THE BOSTON Our knowledge of the causative factors concerned in the extremely prevalent catarrhal affections of the upper respiratory tract, popularly known as "common colds," is in an exceedingly chaotic state. The epidemiologic evidence seems to indicate clearly that these conditions are infectious; and this has led numerous investigators to attempt to isolate a causative organism. An etiologic relation to these infections has been ascribed to Bacillus influenzae, Streptococcus hemolyticus, Streptococcus viridans, the pneumococcus, Micrococcus catarrhalis, Tunnicliff's B. rhinitis and many other organisms. Some time ago, Kruse1 pointed out that, while common colds are undoubtedly infectious, the paucity of bacteria in the secretions and the short time that these few persist militates against the presumptive evidence that they are concerned in the infection.In attempting to trace the causative factor by means other than the bacteriologic methods that had been resorted to previously, Kruse succeeded in producing colds experimentally with a filtrate obtained from the nasal secretion of an assistant who was ill with coryza. The secretion blown from the nose was diluted fifteen times with normal salt solution and passed through a small Berkefeld filter. A few drops of the filtrate dropped on the nasal mucosa of each of twelve men produced acute colds in four, or 33 per cent., of the twelve. The incubation period varied from one to four days. Repetition of this experiment on a more elaborate scale gave confirmation to his earlier results. In the second experiment the nasal secretion was diluted twenty times and, of the thirty-six students who vol¬ unteered for inoculation, 42 per cent, became ill with the usual symptoms of coryza within from one to four days. Kruse states that he was unable to demonstrate living organisms in his filtrates by bactériologie meth¬ ods, and concludes that the causative organism should be classified with the filterable viruses. From the Laboratory of Preventive Medicine and Hygiene of the Harvard Medical School. 1. Kruse, W. : Die Erreger von Husten und Schnupfen, M\l=u"\nchen. med. Wchnschr., 1914, lxi, 1547.During the past winter I...

Studies in the Aetiology of Epidemic Influenza.

“…That colds are due to the Aphanozoa coryzae, as he termed his virus, has-not been proved. , Foster (14,15) in America repeated and supplemented Kruse's work and claimed, in addition, that he had succesfully grown the virus. Cultures were obtained from the filtered nasal secretions of ordinary colds.…”

Studies in the Common Cold. II. A Study of Certain Gram-negative Filter-passing Anaërobes of the Upper Respiratory Tract

“…It is perfectly clear that several of these, such as, hemolytic streptococcus, B. pfeifferi, Staphylococc,ts aureus and pneumococcus, play an important part in the later phases of infection or in complications, but the actual inception of the cold would seem to be due to an organism or organisms as yet unknown. Much favorable evidence has been put forward (chiefly by transmission experiments) to implicate a filterpassing virus (Kruse (1), Foster (2), Olitsky and McCartney (3)); other observers, however, have obtained unconvincing results (Schmidt (4), Williams et at. (5), Branham and Hall (6), Robertson and Groves (7)).…”