RELAPSING FEVER 223 



pod, and indications of a longitudinal, rather than a transverse division, 

 would indicate protozoal affinities. 



It would seem from recent investigations that both methods occur longitudinal 

 division occurring when there are few organisms in the blood and transverse at the 

 height of the infection. 



Minchin has adopted the name Spiroschaudinnia, proposed by Sambon, for the 

 parasitic blood spirochaetes 



S. recurrentis. This is the organism of relapsing fever. It was formerly con- 

 sidered a bacterium and was termed the Spirochaeta obermeieri (discovered by 

 Obermeier in 1873). 



It is present in the blood of persons suffering from the disease during the pyrexia. 

 During the apyrexia they are not found in the peripheral circulation. At this time 

 they are present in great numbers in the spleen where they are actively phagocytized. 



FIG. 60. Spirochaetae of relapsing fever from blood of a man. (Kolle and 



Wassermann.} 



The disease is supposed to be transmitted by bedbugs or lice. Monkeys are sus- 

 ceptible and, after passage of the organism through monkeys, rats can be infected. 



S. duttoni. This is the cause of South African tick fever or " tete-fever. " The 

 disease is similar to relapsing fever, but there are generally four or five febrile par- 

 oxysms with apyrexial intervals. The disease is readily transmitted to ordinary 

 laboratory animals, especially the rat. 



A certain degree of immunity is conferred by an injection with a certain spiro- 

 chaete, but this does not hold for other species; thus, rats which have recovered 

 from S. recurrentis can be infected by S. duttoni and vice versa. The disease is 

 transmitted by the bite either of the adult or larval Ornithodoros moubata. Koch 

 found spirochaetes in the eggs of the ovaries of ticks which had fed on persons with 

 the disease. It is thus an instance of hereditary transmission. 



Leishman, who believes in the protozoal nature of these organisms, has observed 

 clumps of chromatin granules in the Malpighian tubes and in the ovaries of infected 

 ticks, which granules he considers developmental stages. Material showing such 



