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CHAPTER XIV. 

 TICK FEVER. 



AFRICAN RELAPSING FEVER. 



AN acute specific fever closely resembling relapsing 

 fever both in its symptoms and in being associated with 

 the presence of spirochastes in the blood. Infection is 

 transmitted by the bite of a tick. 



Tick fever occurs throughout the greater part of 

 Tropical Africa. Livingstone and other early travellers in 

 Central Africa had recorded the occurrence of a fever 

 attributed by natives to the bites of a certain tick, Ornitho- 

 dorus moubata. The disease was well known to the 

 Portuguese and other European inhabitants of the upper 

 reaches of the Zambesi and in Central Africa, but it was 

 not till 1903 that Philip Ross and Hodges, working in 

 Uganda, discovered in the blood, first of an Indian, and 

 later of Africans and of ' one European, suffering from 

 symptoms similar to those of relapsing fever, a spirillum 

 which they considered was probably identical with 

 Spirochceta obermeieri. Following up this discovery, 

 Philip Ross in 1904 demonstrated the presence of a spiril- 

 lum in the blood of several natives of Uganda suffering 

 from an illness which the patients themselves ascribed 

 to the bites of ticks. Independently, but somewhat 

 earlier, Nabarro had made the same discovery, but his 

 researches were not published for some years. 



In 1904 Button and Todd, working in the Congo Free 

 State, also met with cases of tick fever, and showed 

 that it was due to a spirillum which they also thought 

 was probably identical with S. obermeieri. They were 

 further able to reproduce the disease in monkeys by 



