DIPHTHERIA 293 



Infection can also be conveyed by means of milk (see p. 211). 

 Clothing and other articles which have been in contact with infected 

 persons may carry the bacillus. Birds and cats also have been, as 

 far as can be judged, channels of infection (Klein, Bruce Low, and 

 others). But there is from a bacteriological point of view another 

 body of facts altogether which affect the spread of the disease, namely, 

 the behaviour of the baciUus in the throat. 



The Diphtheria Bacillus in the Human Throat.— Since 1896 



it has been known that the diphtheria bacillus may remain for long 

 periods in the throat. 



" The persistence of the diphtheria bacillus for periods up to eight 

 weeks is of very common occurrence whether antitoxin be given or 

 not; indeed, the majority of cases appear to retain bacilli in the 

 throat for from two to nine weeks."* After the ninth week, the 

 number falls off very rapidly, but not infrequently the bacillus 

 remains in the throat for 100 days, and it has been known to 

 remain more than 200 days. This persistence of diphtheria bacilli 

 in the throat may play an important part in determining the spread 

 of the disease by means of such cases which are supposed to be no 

 longer infective. "For it is now a matter of common experience 

 that so long as these diphtheria bacilli, even the less virulent forms, 

 remain in the crypts of the tonsils, etc., so long is the patient a 

 centre of infection, the diphtheria bacilli present resuming, under 

 favourable conditions, their more virulent form" (Woodhead). In 

 this way diphtheria bacilli can be readily transmitted by patients 

 who are apparently no longer suffering from the effects of the disease, 

 to those who have weak or ulcerated throats. In precisely a similar 

 manner, may the bacillus be conveyed to articles of attire and articles 

 of food, such as milk (as at Leeds in 1903). 



Further, whilst in 72 per cent, of notified definite cases of 

 diphtheria the bacillus may be found, it has been shown that in 

 apparently healthy persons who have not suffered from diphtheria, 

 the B. dipMherice may be present. Loffler found diphtheria bacilli in 

 the throats of 4 out of 160 healthy children, and Park and Beebe 

 found similar virulent bacilli in 8 out of 330 "healthy" throats. 

 Hewlett and Murray found 15 per cent, of the children in a general 

 hospital had diphtheria bacilK in their throats.f Kober % examined 

 diphtheria cultures from two series of healthy persons. The first 

 series comprised 128 individuals known to have been in recent contact 

 with patients suffering from diphtheria. The diphtheria bacillus was 



* Report on the Bacteriological Diagnosis and Antitoxic Serum Treatment of Cases 

 admitted to the Hospitals of the Metropolitan Asylums Board, 1895-96, by Professor 

 Sims Woodhead, sect. 2, 1902, pp. 14, 28, 31. 



t Brit. Med. Jour., 1901, vol. i., p. 1474. 



J Revue des Maladies de VEnfance, Juillet, 1900. 



