TICK FEVER 205 



In the autopsy of the fatal case which Dutton and 

 Todd met with, the liver and spleen were enlarged, the 

 heart muscle showed slightly fatty change, the lungs were 

 pale but otherwise normal and the kidneys were enlarged 

 and showed fatty degeneration. The other organs 

 examined appeared normal, but there was some blood- 

 stained fluid in the abdomen. The blood was fluid and 

 resembled blood-stained water. Spirochaetes were found 

 in it at the time of the autopsy. 



In animals dying of tick fever the post-mortem appear- 

 ances are similar to those observed in relapsing fever 

 in man. Thus, in post mortems on monkeys, Breinl and 

 Kinghorn found the spleen to be greatly enlarged, deeply 

 congested and very soft. It often contained haemor- 

 rhagic infarcts and necrotic areas ; similar changes were 

 found in the liver ; the lungs were cedematous and 

 contained infarcts and the heart muscle was much 

 degenerated. The lymphatic glands \vere frequently 

 haemorrhagic and all organs showed signs of congestion. 

 Spirochaetes were found in the spleen and bone-marrow 

 and also in other organs. 



The etiology of tick fever is indicated by its names, i.e., 

 tick fever and African relapsing fever. As the parasite 

 can be cultivated outside the body in special media such 

 as mouse broth, with mouse blood and yolk of egg, 

 all of Koch's requirements for proving that the disease is 

 due to the S. duttoni have been fulfilled. Previously, in 

 view of the fact that infection can be transmitted by the 

 offspring of ticks which have fed upon patients, even this 

 condition was practically complied with. The sub- 

 cultures retain their virulence. 



That infection is ordinarily transmitted by ticks the 

 0. moubata admits of little or no doubt. It is, however, 

 of some interest to mention that although negroes have 

 long persisted in attributing this role to the ticks, Euro- 

 pean medical men were unable to demonstrate it as a 

 fact until quite recently. It has been seen that infection 

 can also be conveyed by direct inoculation of blood 



