622 Relapsing Fever 



The Spirochaete duttoni is said by Koch,* in his interest- 

 ing studies of "African Relapsing Fever," to resemble the 

 Spirochaete obermeieri in all particulars. 



The spirochaete with which Novy and Knappf experi- 

 mented, and which they believed to be identical with 

 Spirochaete obermeieri, seems to be smaller than that met 

 with in Europe. It measured 0.25-0.3 /* in breadth by 

 7-19 ,'j. in length. The number of coils varies from three 

 to six. The shorter forms are pointed, with a long flagel- 

 lum at one end and a short one at the other. 



Staining. The spirochaetes can be stained with ordinary 

 anilin dye solutions, by the Romanowsky and Giemsa 

 methods, and by the silver methods (see Treponema 

 pallidum). It does not stain by Gram's method. 



Cultivation. The organism will not grow upon any 

 known culture medium. Following the suggestion of 

 Levaditi, Novy and KnappJ cultivated Spirochaete ober- 

 meieri in collodion sacs in the abdominal cavity of rats, 

 and succeeded in maintaining it alive in this way through 

 twenty consecutive passages in sixty-eight days. They 

 were able to do this in rat serum from which all corpuscles 

 had been removed by centrifugation, so that it is proved 

 that no intercellular developmental stage of the organism 

 takes place. Organisms thus cultivated are attenuated in 

 virulence. 



Mode of Infection. The means by which Spirochaete 

 obermeieri is transmitted from individual to individual is not 

 definitely known. Tictin seems to have been the first to 

 believe that the transmission of the disease was accomplished 

 through the intermediation of some blood-sucking insect. 

 He investigated lice, fleas, and bed-bugs, in the latter of 

 which he was able to find the organisms, and through blood 

 obtained from which he was able to transmit the disease to 

 an ape. He was not able to infect apes by permitting infected 

 bed-bugs to bite them. Breinl and Kinghorn and Todd|| 

 made a careful study of the subject, but, like Tictin and 

 their other predecessors, were unable to infect monkeys by 

 permitting infected bed-bugs to bite them. 



* "Berliner klin. Wochenschrift," Feb. 12, 1906, xxxiv, No. 7, p. 185. 



f "Jour. Infectious Diseases," 1906, in, p. 291. 



t "Jour. Amer. Med. Assoc.," Dec. 29, 1906, XLVII, p. 2152. 



"Centralbl. f. Bakt. u. Parasitenk.," i Abt., xv, 1894, p. 840. 



|| Ibid., Oct., 1906, xui, Heft 6, p. 537. 



