Diphtheria iu Man. 437 



crusty eczema of the skin due to contamination with the conjunctival 

 secretion. The ducks became much emaciated and many died within 

 a few weeks, yet autopsy failed to reveal any marked changes in the 

 internal organs. Bacilli of the type of pseudo-diphtheria bacilli were 

 found m the conjunctival exudate. (Centralbl. f. Bakt., 1903, 214.) 



Diphtheria in man. This so justly feared disease of children, 

 produced by the bacillus diphtheriae hominis discovered by Klebs and 

 more carefully studied by Loeffier, and belonging to the group of coryne- 

 bacteria, consists of an .acute diphtheritic inflammation of the mucous 

 membrane of the pharynx and upper air passages, beginning usually 

 with fever and associated with severe constitutional symptoms. The 

 Klebs-Loeffler diphtheria bacillus displays its pathogenic action through 

 the medium of toxins which on the one hand produce a local inflam- 

 matory and necrotic process as well as general constitutional symptoms, 

 and is also responsible for later nerve paralysis which sometimes follow 

 diphtheria. Horses treated with the toxic filtrates of the cultures fur- 

 nish an effective antitoxic serum. 



The relationship between diphtheria of man and that of animals 

 and particularly that of birds has not been fully explained. 



There remains no doubt whatever that true diphtheria of man 

 and the diphtheria of animals are two separate diseases, occurring and 

 spreading entirely independently of one another. The bacillus of 

 human diphtheria, however, possesses a pathogenic action for animals, 

 among them for birds, and as some species, such as young guinea 

 pigs, cats and dogs, after artificial inoculation, develop even croupous- 

 diphtheritic processes of the mucous membranes, it cannot be denied 

 that this bacillus under natural conditions may produce similar 

 disease in animals and thus cause the latter to spread the con- 

 tagion. This view is supported by Ferre, and by "Wheeler and Brandt, 

 who from cases of avian diphtheria and from the mouth of diph- 

 theritic pharyngeal disease of sick dogs respectively, grew cultures of 

 bacilli whose pathogenic action was similar to that of the Klebs-LoefQer 

 bacillus. Further support comes from Cob.bett, who found a bacillus 

 in the nasal secretion of a horse suffering from laryngitis, which cor- 

 responded not only morphologically, but in its pathogenic action with 

 the bacillus of human diphtheria and against which the antitoxic diph- 

 theria serum proved effective. Gallez, Jr., Gratia & Lienaux also 

 found a bacillus similar to the Klebs-Loeffler bacillus but less virulent, 

 in the contagious nasal catarrh of birds. 



On the other hand the possibility cannot be excluded that occa- 

 sionally the diphtheria of animals may produce diphtheritic processes 

 in man. This may be presupposed particularly for those cases where 

 in the products of the diphtheritic mucous membrane inflammation in 

 man it is impossible to demonstrate the Klebs-Loeffler bacillus, and 

 which in all probability results from some other etiological factor. 

 Close relationship between avian diphtheria and that of man has 

 repeatedly been affirmed, based on experiments or observations which 

 appeared to indicate the likelihood of transmission of the disease from 

 man to birds. Loir & Ducloux'have succeeded in cultivating the same 

 bacillus from the pseudo-membranes of a child suffering from diphtheria 

 which they considered to be the virus of avian diphtheria, basing their 

 opinion on the results of their experiments. Finally it is worthy of 

 note that the so called pseudo-diphtheria bacillus which several authors, 

 among them Roux & Yersin, Frankel, et al., believe to be an avirulent 



