100 Biology 



servants' quarters should be established at a distance from the white 

 lines. In travelling, old camp sites and resting places should as far as 

 possible be avoided. " Native servants who are allowed to enter sleeping 

 apartments of whites should be compelled to change their clothing on 

 coming from native quarters." (Wellman MS.) 



Ornithodoros moubata in Relation to Disease. 



African Relapsing Fever in Man or " tick fever " occurs in German 

 and British East Africa, in Central Africa, in the Congo Free State and 

 Angola. The disease was referred to by Livingstone, and it has been 

 mentioned by various travellers in Africa 1 . The main symptoms are 

 headache (especially at the back of the head), vomiting, abdominal pain 

 and purging, with severe fever, a pulse of 90 — 120, dry hot skin, 

 congested eyes and shortness of breath. After a period of fever lasting 

 about two days, there is a fall of temperature, but a fresh attack soon 

 follows. These relapses occur more frequently than in European 

 relapsing fever, being usually 5 — 6 in number, but there may be 

 more. The attacks leave the patient in a weak condition for a long 

 time after recovery which usually follows, but death occurs in about 6% 

 of the cases. The fever attacks are due to protozoal parasites, the 

 Spirochaeta duttoni, which multiply in the blood, the greatest number 

 being present in the blood during the attacks of fever. The disease 

 lasts 1 — 3 weeks or longer, depending upon the number of relapses. 



The Spirochaeta duttoni is transmitted to man by the bites of 

 infected 0. moubata, as has been proved by scientific experiments. The 

 natives of parts of Africa (Angola, Congo, Uganda, Abyssinia, Somali- 

 •land, German E. Africa) have for a long time attributed the fever to the 

 bites of this tick. In describing the effect of the tick's bite, according 

 to Christy (1903, p. 187), the natives in Uganda " invariably go through 

 a pantomime indicative of vomiting, with pain in the head and abdominal 

 region." 



The attack of fever usually follows 5 — 10 days after the susceptible 

 person has been bitten. The Spirochaeta duttoni was discovered by 

 A. R. Cook (Jan. 1904 ; this author took it for Sp. recurrentis) and by 

 Philip Ross and Milne (Nov. 1904, in Uganda), and the part played 

 by the tick was demonstrated by Dutton and Todd (Feb. 1905, in 

 the Congo), and subsequently by R. Koch (Nov. 1905, in German East 



1 See Hinde (1897, p. 3), Plehn (1902), etc., who state that the disease is referred to 

 tick-bites by the natives. 



