DIAGNOSIS OF AFRICAN TICK FEV^R. 243 



It may be stated in relation to the employment of the agglutinative 

 test for this purpose, that, as has already been pointed out, owing to the 

 difficulties of technique in performing the reaction and to the fact that 

 in tick fever infections the agglutinins sometimes do not become de- 

 veloped until after several relapses or reinfections with the spriochfeta3 

 have occurred (a fact to which Manteufel 2S recently called attention for 

 infections with Spirochceta obermeieri) the agglutinative reaction even 

 in low dilutions also does not constitute a satisfactory means of diagnosis. 20 



For the present, the most efficacious methods at our disposal are the 

 microscopic examination of the peripheral blood and of that obtained by 

 puncture of the liver and spleen, both in fresh and in stained preparations, 

 and by animal inoculations with the blood when suitable species are at 

 hand for this purpose. Usually, a marked polymorphonuclear leucocytosis 

 occurs, frequently before the crisis, and it usually persists for a day or 

 two, after it. At the latter time, an increase of the large mononuclear 

 cells may be encountered. It should be remembered that even in cases 

 well marked from a clinical standpoint, the microscopic specimens of the 

 centrifugated blood may be examined an hour or two before a single 

 parasite is finally discovered. If the parasites are not found by the 

 examination of the blood, inoculations of white mice, white rats or 

 monkeys with the blood of the suspected patient shoidd be carried out 

 if practicable. If the spirochsette develop in the blood of the animal, 

 they may if it is thought desirable be differentiated by means of specific 

 agglutinating sera. Clinically, it is sometimes quite impossible to dis- 

 tinguish African tick fever from several other febrile infections. 



I have seen in a hospital at one time as many as five cases diagnosed 

 as spirochaetal fever infections by a competent physician, thoroughly 

 familiar with the clinical picture of relapsing fever and accustomed to 

 seeing numerous cases of this disease. I was unable to find a single 

 spiroelueta in the blood of any of these patients. 



Theoretical^, it is very easy to distinguish tick fever from typhus 

 fever, malaria, trypanosomiasis and Kala-azar by the blood changes. In 

 practice, this is at times most difficult, and the individual case may 

 require considerable study before a correct diagnosis can be made. 



In conclusion, I wish to express my thanks to Professor Nocht, 

 Professor Fullerborne, Professor Geimsa and Professor Prowazek, for 

 many courtesies extended to me during my stay at the Institut fur 

 Schiffs- und Tropen-Krankheiten, where most of the laboratory ex- - 

 periments described in this paper were performed. 



28 hoc. tit. 



=0 No attempt was made to employ the reaction of the deflection of the com- 

 plement for diagnostic purposes in these spirochaetre infections, for the reason 

 that it appears that the definite value of this reaction has not as yet been entirely 

 determined for bacterial infections. 



