512 



AFRICAN TICK FEVER 



louse is the agent of transmission of the human disease is 

 strongly supported by the experiments of Manteufel, who was 

 able to transmit infection from rat to rat in nearly 60 per cent, 

 of the experiments made, whereas he obtained only negative 

 results by means of bugs. Fehrmann considers that the clothes 

 louse may carry the infection. Further observations are still 

 necessary. 



African Tick Fever. 

 The disease long known by this name as prevalent in Africa 



Fig. 154. — Film of human blood containing spirochete of tick fever. 

 X 1000.1 



has also been shown to be caused by a spirochete — sp. duttoni. 

 Organisms of this nature had been seen in the blood of patients 

 in Uganda by Greig and Nabarro in 1903, and Milne and Ross 

 in the end of 1904 recorded a series of observations which led 

 them to the conclusion that tick fever was due to a spirochete. 

 It is, however, chiefly owing to the work of Dutton and Todd 

 in the Congo Free State, on the one hand, and of Koch in 



i We are indebted to Col. Sir William Leishman, R.A.M.C., for the prepara- 

 tions from which Figs. 153-55 were taken. 



