RESEARCHES ON ACAR1DS AMONG LEPERS. 



By M. Lefebvre. 

 {From the Biological Laboratory, Bureau of Science, Manila, P. I.) 



M. Borrel in 1909 published two very interesting papers, ''Aeariens 

 et Cancers" and "Aeariens et Lepre," 1 in which he proposed the 

 hypothesis based on noteworthy observations, that the agent of propaga- 

 tion of both these diseases might be an acarian parasite, namely, Demodex 

 folliculorum Simon. 



I have taken up the critical examination of this hypothesis so far as it 

 concerns leprosy. The materials for the present investigation have been 

 taken from lepers of the San Lazaro Hospital in Manila. The following 

 methods principally were employed in their collection and study. 



1. Contents of the sebaceous glands collected in vivo. — To extract the contents 

 of the sebaceous glands, I usually made use of glass tubes, one end of which I 

 reduced to a filament having an interior diameter of 2 millimeters. By properly 

 pressing this open end on the skin so that it circumscribed the opening of a 

 sebaceous gland, the entire product of the gland was forced up into the tube, 

 and the contents of the latter then pushed by a straw onto a microscopical slide. 

 The individuals of Demodex, if there are any, are by this means almost certain to 

 be extracted, for they are always found at the bottom of the sebaceous cavities. 



There is a chance of at least one error in the microscopic examination of this 

 substance, for it often happens that in the mass of sebum there occur small, 

 molded portions which so closely resemble the body of Demodex that it is nearly 

 impossible to distinguish them from it, and all the more so because the granula- 

 tions and the greasy consistency of the mass make it indistinct. Hence it is 

 necessary to clear the preparation by a solvent. After various trials with ether, 

 alcohol-ether, chloroform, potassium hydroxide, potassium carbonate, borax, etc., 

 I decided on a solution of borax; the greasy substance disappeared by its use and 

 it was easy to recognize the bodies which remained after the treatment. 



2. Cutaneous nodules excised from living lepers. — Nodules not yet ulcerated 

 must be chosen. The ablation is often almost painless, as many of them are 

 anaesthetic. 



3. Pieces taken at autopsy. — The lobes of the ear; sides of the nose; pieces of 

 skin cut off around the various nodules; portions of the characteristic mouiliform 

 nerves, and internal organs, the spleen in particular, were used in order to com- 

 pare the bacilli found therein with those observed in the skin. 



1 Ann. Inst. Past. (1909), 23, 100, 127. 



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