508 RELAPSING FEVER 



observations were fully confirmed, and his views as to its causal 

 relationship to the disease have been established as correct. 



Within recent years relapsing fever has been carefully studied 

 in different parts of the world, and the relationships of the 

 organisms have been the subject of much investigation and 

 discussion. This question will be referred to again below. 

 Recently also it has been shown that the so-called "tick fever" 

 prevalent in Africa is due to a spirochsete of closely similar 

 character, and results of the highest importance have been 

 established with regard to the part played by ticks in the 

 transmission of the disease. As a matter of convenience, we 

 shall give the chief facts regarding these diseases separately. 

 It has also been shown that spirillar diseases or " spirilloses," as 

 they are called, are widespread amongst vertebrates ; they have 

 been described, for example, in geese by Sacharoff, in fowls by 

 Marchoux and Salimbeni, in oxen and sheep by Theiler, and in 

 bats by Nicolle and Comte, and it is interesting to note that in 

 the case of the spirilloses of oxen and fowls the infection is 

 transmissible by means of ticks. 



Characters of the Spirochsete of Belapsing Fever. The 

 organisms as seen in the blood during the fever are delicate 

 spiral filaments which have a length of from two to six times 

 the diameter of a red blood corpuscle. They are, however, 

 exceedingly thin, their thickness being much less than that of 

 the cholera spirillum. They show several regular sharp curves 

 or windings, of number varying according to the length of the 

 organisms, and their extremities are finely pointed (Fig. 152). 

 They are actively motile, and may be seen moving quickly across 

 the microscopic field with a peculiar movement which is partly 

 twisting and partly undulatory, and disturbing the blood corpuscles 

 in their course. There are often to be seen in the spirals, portions 

 which are thinner and less deeply stained than the rest, and 

 which suggest the occurrence of transverse division. Fantham 

 and Porter find that the sp. Obermeieri and sp. Duttoni multiply 

 both by longitudinal and by transverse division, the former 

 occurring especially during the onset of the fever. 



They stain with watery solutions of the basic aniline dyes, 

 though somewhat faintly, and are best coloured by the 

 Romanowsky method or one of its modifications. When thus 

 stained they usually have a uniform appearance throughout, or 

 may be slightly granular at places, but they show no division 

 into short segments. They lose the stain in Gram's method. 

 There is no evidence that they form spores. 



Novy found that the spirocheete of American relapsing fever 



