APPENDIX C 295 



and the disease are communicated by the common bed- 

 bug. In 1903 Dr. Philip Ross found spirochaetae in a 

 case of fever at Entebbe (Uganda), and succeeded 

 in infecting a monkey from the case. In 1904 Dr. 

 Milne found spirochaetae in the blood of eight cases 

 of fever, which the patients themselves (natives of 

 Uganda) ascribed to the bites of ticks. In the same 

 year Dutton and Todd, in the Congo State, discovered 

 that the spirochaeta was communicated by the bite 

 of a naturally infected tick, Ornithodoros nioubata ; 

 they also found that they could infect monkeys with 

 the disease by feeding newly hatched ticks upon them, 

 and thus proved the hereditary transmission of infective 

 powers from the parent tick to the offspring through 

 the &%%. 



There are differences of opinion as to the exact 

 nature of spirochaetae, and biologists have not yet 

 decided whether they should be regarded as bacteria 

 or as protozoa. The spirochaeta of African tick fever, 

 on account of its great length, its somewhat different 

 appearance (it is often seen arranged in a circle or 

 coiled like a figure of eight), and on account of the 

 shorter febrile period to which it gives rise, has been 

 differentiated from the spirochaeta of European re- 

 lapsing fever, and has been named Spirochceta Duttoui. 

 The spirochaetae may be found in the blood during 

 the attacks, and they become less numerous with 

 each relapse. The most convenient method of staining 

 them, in a tropical country, is with Leishman's stain. 



The incubation period is from two to eight or ten days. 



The onset of the disease is usually quite sudden. 

 The patient feels not quite well, the temperature begins 

 to rise, and in a few hours he is in a state of prostration. 



The symptoms are fever, vomiting, and headache. 

 The temperature rises to 103 to 105° F., and remains 

 fairly constant, though it is rather lower (perhaps roi°) 



