DIAGNOSIS OF LEPROSY 99 



were made by Bayon and they alone gave rise to tissue changes resembling those of 

 leprosy when injected into animals. 



Professor Deycke obtained a streptothrix-like growth from the granulomatous 

 tissue of excised leprous nodules. The ethereal extract from this culture gave a 

 neutral fat which he called nastin and which is the basis of a leprosy treatment. 



Quite recently and after working for eighteen months, with material 

 from 32 nonulcerative cases of nodular leprosy, not only with media as 

 recommended by Duval, Rost and Bayon, but with blood and serum 

 culture media, both by aerobic and anaerobic procedures, Fraser has 

 been unable, in a single instance, to obtain any evidence of growth from 

 this wealth of leprosy material. 



As being opposed to the possibility of culturing the human leprosy bacillus, it 

 may be stated that most of the experiments along this line with rat .leprosy, a 

 disease occurring naturally in rats and caused by an organism almost identical, as 

 to lesions produced, with the leprosy bacillus, have been negative. Bayon, however, 

 states that he has cultivated the bacillus of rat leprosy. 



Recently a leprosy-like disease of rats has been reported in which there are two 

 types: i. A skin affection and 2. a glandular one. In this disease, acid-fast, 

 bacilli, alike in all respects to leprosy bacilli, have been found. Deane has obtained 

 a diphtheroid-like organism in culture, which is nonacid-fast. This same finding 

 has been obtained in cultures considered positive in human leprosy. 



There have been many reports of positive findings with the Wassermann test in 

 cases of tubercular leprosy but such reports are considered doubtful by many. 

 Butler, in the Philippines, has found that the lepers gave no higher percentage of 

 positive Wassermann reactions than did the nonleprous native patients at his 

 clinic. 



There is nothing definitely known as to method of transmission of 

 the disease. 



In rat leprosy it has been found that infection of other rats takes place as readily 

 through slight abrasions of the skin as when material is injected subcutaneously. 



The idea is that natural infection occurs by way of the skin and through the 

 lymphatics. There is no evidence that insects play a part in transmission. 



Rat leprosy prevails extensively in Europe, Asia and America. Although similar 

 etiologically and pathologically there does not seem to be any connection between 

 the disease in rat and in man, as is the case with human and rat plague. 



Laboratory Diagnosis, The usual procedure is to scrape a spot or 

 nodule with a scalpel until the epidermis has been gone through and 

 then smear out the serous exudate on a slide and stain by the Ziehl- 

 Neelsen acid-fast method or by Gram's stain. Twenty percent sul- 

 phuric acid is less apt to decolorize than the 3% acid alcohol, the lep- 

 rosy bacilli being less resistant to acid alcohol decolorization than to 



