542 SCIENCE IN AFRICA 



in Kenya, and Hennessey (1934) in Uganda, where a definite 

 outbreak of louse-borne typhus occurred in Kigezi. In that district, 

 the inhabitants wear sheep or goat skins with the wool or hair 

 turned towards the body. The incidence of tick-borne typhus in 

 Kenya has been gradually increasing since it was first recognized 

 in 1924. The severity of the disease also seems to be increasing. 

 Two cases of the tick-borne type have been reported from Uganda, 

 but the louse-borne disease has almost died out as a result of the 

 new disinfestor introduced for village use by Mr. Garnie. It is 

 probable that the louse-borne type exists in the Belgian Congo, 

 as it was from there that the disease first reached Uganda. 



TUBERCULOSIS 



Africa appears to have been free from tuberculosis before the 

 coming of the white man, but the disease is now distributed over 

 much of the continent and seems to be increasing its range. 

 Among Africans, especially those who have not been in contact 

 with the disease before, it takes on a much more virulent form than 

 among Europeans, and the mortality is high. This was first shown 

 in a striking way during the War. Senegalese troops taken to 

 France came from an isolated community which had never been 

 in contact with the disease. In France they were soon infected 

 and the disease passed rapidly through its various stages. Only 

 after the early stages were systematically tracked by frequent 

 examinations was some check put on the waste of life. There is 

 little doubt that the survivors who returned to Africa spread the 

 disease amongst the indigenous population, but it is significant 

 that centres of infection do not seem to have been set up in rural 

 areas, since the known centres to-day are always in towns, where 

 the European element in the population is strongest and the living 

 conditions of natives are particularly bad. 



There are now many foci of tuberculosis all over the continent, 

 the mining areas being the most important. Natives migrate into 

 the infective areas for work and return to spread the disease among 

 their own tribes, but in spite of these apparently favourable con- 

 ditions for dissemination, tuberculosis has not yet become one of 

 the major diseases. Some workers have attributed this to the for- 

 tunate lack of bovine infection, but, though this must militate 



