DIAGNOSIS OF LEPROSY 337 



been inoculated, but the positive results obtained are all 

 open to objection. 



The differentiation of leprosy from tuberculosis, although 

 the bacilli are so similar, does not in the majority of cases 

 present much difficulty. The large number of bacilli 

 present in the lesions, and particularly in the skin, forms 

 a marked distinction from tuberculosis. The Bacillus 

 leprce also stains more readily, and with watery solutions 

 in a shorter time, than does the Bacillus tuberculosis, 

 though this distinction is hardly marked enough for 

 diagnostic purposes. 



Cases of leprosy, both of the nodular and anesthetic 

 varieties, have been treated with injections of Koch's 

 tuberculin, which has been found to produce a certain 

 amount of reaction followed by some amelioration in 

 their condition. Rost and Williams with their cultures 

 have prepared vaccines with which treatment is being pur- 

 sued. Nicholls and others have used extracts of leprous 

 tissue as a vaccine, and Bayon states that a filtered extract 

 of the Kedrowsky culture is of service for treatment. 



Dean x and others have met with a leprosy-like disease in the rat. 

 Marchoux found about 5 per cent, of the sewer rats in Paris infected 

 with it. Nodules are found in the tissues which contain large 

 numbers of an acid-fast bacillus closely resembling the B. leprce^ 

 Material from infected rats inoculated into healthy rats reproduces 

 the disease after some months, but has no effects on guinea-pigs. 

 The disease is probably conveyed by contact. 



Dean cultivated a diphtheroid non-acid-fast bacillus from this 

 disease ; Bayon an acid-fast leproid bacillus which he finds to be 

 very similar to that obtained by him from human leprosy. 



Clinical Examination 



(1) If cutaneous nodules be present, one is clamped, pricked, and 

 films are prepared with the juice that exudes and stained as for 



1 Journ. of Hyg., vol. v, 1905, p. 99 ; Marchoux and Sorel, Ann. de 

 Vlnst. Pasteur, xxvi, 1912, p. 778. 



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