CLIMA TOLOGY—MTIOLOG Y 



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of Edinburgh defined this mild type as a fever distinct from typhus, 

 and about the same time it was recognized in Germany, and some- 

 what later in Russia. 



In 1868 there was an epidemic in Berlin, when Obermeyer, one 

 of Virchow's assistants, first saw a spirochsete in the blood of a 

 patient; but he does not appear to have been very certain about 

 this at the time, for he waited till the next epidemic in 1872, and 

 even then did not publish his account till 1873. This spirochsete 

 was named S. recurrentis by Lebert in 1874, and 5. obermeyeri by 

 Cohn in 1875, and was proved by Miinch, of Moscow, to be the 

 cause of the disease by the successful inoculation of blood containing 

 the spirochaetes into healthy human beings — an experiment which 

 has since often been repeated accidentally at post-mortems. It has 

 been inoculated with success by Metchnikoff and others into 

 monkeys and mice. In 1888 Sakharoff suggested that this organism 

 was a protozoon — a view which later met with great support. 



In Russia, where the disease has been well known since 1863, there is a 

 popular belief that it is spread by the bed-bug Clinocoris lectularius L., which 

 belief was supported by Fliigge in 1891. In 1897 Tictin found that he could 

 infect monkeys by inoculation of the blood obtained by crushing bugs which 

 had very recently been fed on a patient — i.e., within forty-eight hours. 



Spirochaetes have been found in bugs during relapsing fever epidemics by 

 Karlinski in 1902, and later by Schaudinn. Nuttall has successfully trans- 

 mitted 5. recurrentis from mouse to mouse by the bites of bugs. Donitz's 

 hypothesis, that 5. recurrentis is conveyed by ticks, has not been supported 

 by experiments. 



The role of the louse in this disease has been studied by Koch 

 and by Werner and Wiese in 1917, but requires the accurate study 

 given to the North African type by Nicolle, Blaizot, and Conseil. 

 It has also been studied by Toyoda, who has shown it to be closely 

 related to the North African type by means of immunity experiments. 



Climatology. — ^The disease is endemic in Russia, Ireland, Turkey, 

 the Balkans, Denmark, Norway, Bohemia, and in some parts of 

 Poland and Germany, while the same or a similar type is found in 

 Lower Egypt, in Southern China, and perhaps in the Philippines. 

 There, however, appears to be some doubt about the presence of 

 the disease in these islands; the authority for the statement ds 

 McCrae, in Osier's ' System of Medicine.' 



etiology, — ^This type of relapsing fever is caused by 5. recurrentis 

 Lebert, 1874, which is generally to be found in the peripheral blood 

 during the attacks, but is usually absent in the apyrexial interval, 

 though individuals may occasionally be found after prolonged 

 search. (For description of the organism, see p. 443.) 



This spirochaete is carried from the sick to the healthy by the 

 agency of lice, P. humanus and P. corporis (see p. 917). The 

 subject, however, requires further study on the lines of the North 

 African type {vide infra). It is known that the human blood is 

 infective during the pyrexial and apyrexial stages, and that the 

 spirochaetes reach the coelom of the louse between the second and 



