DIPHTHERIA AND MILK 331 



from the disease and transmit it to man. Savage, 1 how- 

 ever, can obtain no evidence of this and finds that cats 

 are insusceptible to diphtheria. The diphtheria bacillus 

 has been isolated from the horse by Cobbett. 



Several epidemics of diphtheria have been traced to an 

 infected milk supply. In some instances the infection 

 has undoubtedly been derived from contamination from 

 a human source, e.g. in an outbreak in Lambeth, Priestley 

 traced the infection to a particular dairy in which a 

 dairyman with an ulcerated thumb was employed and the 

 ulcer was infected with virulent diphtheria bacilli ; in 

 others the source of infection has not been demonstrated, 

 but there is always the possibility of an employee being 

 a carrier. It has been suggested that certain eruptive 

 conditions on the teats and udder of the cow may be 

 caused by the Klebs-Loffler bacillus and the milk become 

 infected therefrom. Klein inoculated healthy cows in 

 the shoulder with a broth culture of the diphtheria 

 bacillus. This caused fever and local swelling, and in 

 about a week a papular and vesicular eruption appeared 

 on the udders and teats. The B. diphtherice was isolated 

 from the contents of the vesicles and also from the milk 

 on the fifth day, but not subsequently. The cows died 

 in two to four weeks, and the B. diphtherice was obtained 

 from the local lesions. Abbott 2 obtained somewhat 

 different results, but Klein 3 pointed out that these experi- 

 ments were not performed under exactly the same condi- 

 tions as his own. 



Klein, Eyre, Dean, and Marshall 4 have isolated the 

 diphtheria bacillus from milk. It is to be noted that 

 diphtheria-like, but non-pathogenic, bacilli are often to be 



1 Journ. of Hygiene, 1920. 



2 Journ. Path, and Bact., vol. ii, 1894, p. 35. 



3 Ibid., p. 428. 



4 Journ. of Hygiene, vol. vii, 1907, p. 32 (Refs.). 



