CHAPTER XIX. 



RELAPSING FEVER. 



SPIROCH^TA 



IN 1868 Obermeier* first observed the presence of actively 

 motile spiral organisms in the blood of a patient suffering 

 from relapsing fever. Having made the observation, he 

 continued to study the organism until 1873, when he made 

 his first publication. From 1873 until 1890 it was supposed 

 that spirochaeta rarely played any pathogenic role. Miller 

 had, indeed, called attention to the constant presence of 

 Spirochaeta dentinum in the human mouth, but it had not 

 been connected with any morbid condition. In 1890 

 Sacharofff discovered a spirillary infection of geese in the 

 Caucasus, caused by an organism much resembling Spiro- 

 chaeta obermeieri and called Spirochaeta anserinum. In 

 1903 Marchoux and Salimbenif found a third disease, 

 fatal to chickens, caused by Spirochaeta gallinarum, and 

 found that the spread of the disease was determined by 

 the bites of a tick, Argas miniatus. In 1902 Theiler, 

 in the Transvaal, observed a spiral organism in a cattle 

 plague. This has been named after him by Laveran, 

 Spirochaeta theileri. It was found to be disseminated by 

 the bites of certain ticks Rhipicephalus decolor atus. 

 Later, what was probably the same organism, was found in 

 the blood of sheep and horses. In 1905 Nicolle and Comte|| 

 found a spiral organism infecting certain bats. By this 

 time, therefore, it became evident that spirochaetal infections 

 were fairly well disseminated among the lower animals and 

 that the spirochaeta were of different species with different 

 hosts and intermediate hosts. 



*"Centralbl. f. d. med. Wissenschaft," 1873. 

 t "Ann. de 1'Inst. Pasteur," 1891, xvi, No. 9, p. 564. 

 J Ibid, 1903, xvii, p. 569. 



"Jour. Comp. Path, and Therap.," 1903, XLVII, p. 55. 

 || "Compt.-rendu de la Soc. de Biol. de Paris," July 22, 1905, Lix, 

 p. 200. 



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