446 VETERINARY BACTERIOLOGY 



the body louse (Pediculus vestimenti). Whether or not there is 

 a developmental cycle in the body of the parasite is not certainly 

 known. 



Spirochaeta duttoni 



Synonyms. Spiroschaudinnia duttoni; Spirillum duttoni. 



Disease Produced. West African tick fever in man. 



Ross and Milne, and Button and Todd, working independently 

 in 1904, demonstrated the presence of this spirochete in the blood 

 of individuals infected with this disease. Morphologically, it 



Fig. 197. Spirochata duttoni from the blood of a rat (Novy and Knapp, in 

 "Journal of Infectious Diseases"). 



resembles the preceding closely, but is usually longer and more 

 loosely coiled. It is said to possess diffuse flagella. The disease 

 is transmitted by the bite of a tick (Ornithodorus moubata). 



Duval, Todd, McGell, and Pong have reported success in the 

 cultivation of the organism outside the body. Many media 

 were used with uniform failure until an egg-yolk preparation was 

 found to be successful. The following is the medium recommended 

 by these investigators. Six mice are skinned and their bodies 

 boiled in 500 c.c. of water. This is filtered and sterilized. Two 



