CHAPTER XLIII 



Spirochaeta pertenuis is the cause of a non-venereal tropical skin disease, 

 called "frambcesia tropica," or "yaws." Spirochaeta pertenuis is regularly 

 found in the papules of the diseased before treatment. It has the same size, 

 shape and motility as the treponema pallidum and when subjected to various 

 methods of staining reacts just as the treponema does except that as a rule 

 spirochaeta pertenuis stains more readily. Patients infected with yaws have a 

 positive Wassermann reaction just the same as syphilitics and yaws promptly 

 answers to salvarsan and mercury. 



Some observers believe there is a close relationship between the treponema 

 pallidum and spirochaeta pertenuis. 



Diagnosis is made by pinching one or several of the skin lesions with a 

 hemostat, nicking it with a scalpel so as to obtain serum and not blood. The 

 fluid that exudes is collected in a capillary tube, smeared on cover glasses, dried, 

 fixed in absolute alcohol for 15 minutes and stained with equal parts of Giemsa's 

 solution and water for 20 minutes. 



The large number of distinctly stained spirochaeta observed in every cover- 

 glass preparation, the abundance of these organisms in every lesion, of a fully 

 developed case of yaws, untreated, serves to establish the diagnosis and dif- 

 ferentiate it from syphilis the lesions of which do not so uniformly yield fluid 

 containing demonstrable treponema and almost never show so many organisms. 



Spirochaeta dentium is a saprophyte present in the mouth, particularly 

 between the teeth. It is microscopically indistinguishable from the treponema 

 pallidum. 



Spirochaeta refringens has been found in ulcers of the skin, in smegma and in 

 the mouth. Usually it is larger and more easily stained than the treponema 

 pallidum, yet microscopic differentiation is at times impossible and often 

 questionable. 



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