190 REVIEW — TROPICAL MEDICINE, ETC. 



Spirochaetes Ross' also describes Uganda " Tick Fever," giving several temperature charts. He 



and Spiro- differs in one or tvv'o points from Moffat, finding tliat there may be as many as six relapses in 



chaetosis — the European, and that in the native no relapse may occur. He also notes that the parasites 



continued are usually exceedingly sparse in the blood and that it may take many hours' search to find 



one organism. Where blood examination fails the diagnosis can be made with ease and 



certainty by injecting a drop or two of finger-blood into a monkey. When the animal 



sickens the spirochsette can be found with the greatest ease in the blood. This method, 



however, takes a few days. It is worth noting that there is a relative increase of 



polymorphonuclear leucocytes. 



As regards prevention, this is easy for Europeans but difficult in the case of natives. 

 The Ornithodoros lives by day in the thatch or in cracks of mud-iioors and walls of old native 

 huts. At night it comes out in search of food, retiring again when it has fed. Old camping 

 grounds and old huts should be avoided, infected huts should be burned. Europeans should 

 sleep under mosquito nets, well tucked under the bed-clothes. The liability of natives to 

 relapses is possibly due to repeated re-infection. 



An account of the disease as it occurs in Angola is given by Wellman.- An important 

 experimental study on Spirochseta duttoni was carried out by Breinl and Kinghorn.^ As 

 regards technique, they state :^ 



The routine method of examining the blood for spirocheetes was the ordinary thick-film one. Two or three 

 drops of blood were placed on a perfectly clean slide and then spread out over a surface 2 e.c. by 3 c.c. After 

 drying in the air, the films were fixed in the flame in the same way as a bacteriological specimen, land the 

 hEemoglobin was removed by washing the films in distilled water. After being so treated, they became quite 

 colourless and were then stained with Romanowsky's stain for half an hour. The stain was made in accordance 

 with the directions given by Stephens and Christophers. 



A. Medicinal methylene blue, 1 part 

 Sodium carbonate, O'o ,, 

 Distilled water, 100- „ 



B. Eosin, 1:1000- „ 



Before using, dilute each solution with 19 parts of distilled water, and then mix in equal parts for staining. 

 This method gave us better results than any other modification of Romauowsky. 



In specimens prepared by this method the spirochsetes are well defined and are of a deep purple colour. The 

 leucocytes are well stained, while the red cells appear as mere shadows. The examination is much facilitated by 

 reason of this. 



For more detailed study, very thin films were made on slides heated to 37° C, in order to dry the blood- 

 film more rapidly ; these were fixed in absolute alcohol and stained with the above modification of Romauowsky 

 and by Qiemsa's and Laveran's method. lu our hands Marino's method did not yield satisfactory results. 



When the presence of precipitates interfered with examination, it was found advisable to place the 

 preparation in oil of cloves for a short time, and then in xylol after the excess of oil had been blotted off. 



Carbol-fuchsine stains the spirochEetes very readily and intensely, but is not as valuable a stain as that of 

 Romauowsky. Heidenhain's iron-haematoxylin was also used, but without any advantage, as it stains the 

 spirochaetes uniformly black. 



In order to study the structure of the parasite the wet film method was used. Perfectly clean slides were 

 covered with an exceedingly thin layer of Mayer's albumen. A drop of blood was spread out as quickly as 

 possible over the layer of albumen, and while still wet the slide was dropped into Flemming's fixing solution and 

 left for ten minutes. In this the albumen was quickly coagulated and firmly fixed the blood to the slide. From 

 the fixing solution the slide was passed through the different alcohols and stained. 



The routine examination was made with a Zeiss jVth oil immersion and No. 4 ocular. 



They found by experiment that the blood of patients suffering from relapsing fever 

 is infective for susceptible animals during the period of apyrexia. They compared African 

 tick fever and European relapsing fever, and agreed with Koch as to the shortness of the 

 attacks in tick fever, and as to the small number of parasites in the blood as compared with 

 European relapsing fever. The attacks and relapses are of longer duration in the latter. 



In the study of the animal reactions they found that they could infect nearly all 

 the usual laboratory animals with iS'. duttoni. Cats were refractory to infection. The 

 most susceptible animals were white rats and then monkeys. 



As regards immunity, they note that there is a relatively active immunity against 

 re-infection, as animals re-inoculated at various intervals after recovery up to seven-and-a- 

 half months did not become infected at all or only had a very slight attack. 



1 Ross, P. (March Ist, 1906), " Tick Fever." Journal of Tropical Medicine and Hygiene, Vol. IX. 



^ Wellman, F. C. (April 1st, 1905), " Case of Relapsing Fever, with Remarks on its Occurrence iu the Tropics 

 and its relation to Tick Fever." Journal of Tropical Medicine and Hygiene, Vol. VIII. 



= Breinl, A., and Kinghorn, A. (September, 1906), " An Experimental Study of the Parasite of the African 

 Tick Fever {Spirochiela duttoni)." Mini. Liv. Sch. Trop. Med., No. XXI. 



