TREPONEMATA 523 



Indian, African and American. Noguchi grew the organisms in pure 

 culture for the first time in 1912. Relapsing fever appears to be 

 transmitted chiefly, if not exclusively, by suctorial insects. 



Treponema Recurrentis. Synonyms. Spirillum obermeieri, Spiro- 

 cheta obermeieri, Spirillum recurrentis, Treponema obermeieri, Spiro- 

 cheta recurrentis. 



Relapsing fever is an acute contagious disease which begins abruptly 

 with a chill. The fever which follows immediately after the chill 

 reaches the fastigium (104 to 106) usually within twenty-four hours, 

 remains high for five to seven days, and falls by crisis. There is an 

 afebrile intermission of five to seven days, then the fever is repeated. 1 

 Convalescence usually begins at the close of the second paroxysm; 

 it may not occur until the close of the third or even fourth paroxysm. 

 The incubation period is from two to fourteen days. The mortality 

 is low, less than 4 per cent, of all cases. The spleen is enlarged, there 

 is profuse sweating, frequently jaundice, and occasionally diarrhea. 



Morphology. The organism is spiral in outline and of moderate 

 size. Schellack 2 states that the average diameter is 0.4 micron; the 

 length varies from 15 to 20 microns. Other investigators give as 

 measurements, diameter 0.25 micron, length from 7 to 10 microns. 

 The discrepancy appears to be attributable to the fact that younger 

 organisms are about 10 microns in length, the older forms being much 

 longer. There are from twenty to forty spirals in each individual 

 cell, the number depending upon its length. Very frequently the 

 ends are tapered. Fresh preparations viewed by dark-field illumination 

 exhibit three distinct types of motion: 3, rotation around the long 

 axis, which causes the organism to move rapidly through the medium 

 in which it is suspended, an undulatory movement, and a lateral 

 movement in all planes. The motility is caused by the rhythmic 

 contractions of a terminal flagellum, according to Novy and Knapp. 3 

 Zettnow 4 believes the organism possesses peritrichic flagella. This 

 has not been confirmed. Reproduction takes place typically by longi- 

 tudinal fission according to Noguchi. 5 Less commonly he has observed 

 transverse fission. 



Isolation and Culture. The organism appears in the blood stream 

 only during the pyrexia. Novy and Knapp 6 observed multiplication 



1 Obermeier, Centralbl. f. d. med. Wissensch., 1873, xi; Berl. klin. Wchnschr., 1873, 

 x, 152, 378, 391, 455. 



2 Arb. a. d. kais. Gesamte, 1908, xxvii, 364. 3 Jour. Inf. Dis., 1906, iii, 291. 



4 Deutsch. med. Wchnschr., 1906, xxxi. j our . Exper. Med., 1912, xvi, 207. 



6 Jour. Am. Med. Assn., 1906, xlvii, 2152 



