THE BACILLUS LEPRM 



467 



and that infection takes place through dust or droplets. Recently 

 a case has been described which shows extensive involvement of the 

 liver and spleen, in which the intestinal tract was considered the 

 atrium of infection, Cases also are on record in which the primary 

 lesions appear to have occurred on the feet, indicating that abrasions 

 of the skin may also be portals of entry. 



Diagnosis. Scrapings from the nasal ulcer may give an early 

 diagnosis. It should be remembered, however, that an acid-fast 

 organism described by Karlinski (nasal secretion bacillus) is fairly 

 common, not only in the nasal passages of lepers and tuberculous 

 individuals, but also in normal individuals as well. Karlinski's 

 organism grows readily on artificial media and is in no way related 



FIG. 64. Lepra bacilli in skin. (Kolle and Hetsch.) 



to the leprosy bacillus. As a matter of practice, a clinical diagnosis 

 of leprosy is more important than a microscopical diagnosis; the 

 latter merely confirms the former. From ulcerated lepromata or from 

 intact tuberculoid nodules material may be gathered and stained in 

 the usual manner for the presence of acid-fast organisms. Inasmuch 

 as the leprosy bacilli occur in large numbers in these tubercles it is 

 best to excise a small portion of one, cut sections and stain it for 

 leprosy bacilli. This will give the characteristic arrangement of the 

 organisms and make the diagnosis very much more certain. Leprosy 

 bacilli can be definitely distinguished from tubercle bacilli; when 

 injected into guinea-pigs they do not produce lesions: 



Prophylaxis. Heredity. Whether leprosy is a germinal infection 

 or not is not known, although the bacilli have been found both in the 



