IN THE ILORIN PROVINCE OF NORTHERN NIGERIA. 17 



surroundings at Eri in Plate IV. They are found in the neighbourhood of villages 

 and towns in districts in which Fulani cattle cannot exist, and they have therefore 

 been credited with a natural immunity to trypanosomiasis.* At Ilorin, however, 

 I was able to prove that, in one case at any rate, infection with T. brucei termin- 

 ated fatally, although in two cases recovery from infection with T. vivax was 

 observed to occur, f It is not likely therefore that these cattle would be of any 

 use as transport animals even if they were to prove physically capable of the work. 

 There is some reason to suppose that these cattle, even when living in country 

 haunted by G. submorsitans, may escape the attacks of these insects, as collections 

 of biting flies made at the spots where they were actually grazing did not include 

 this species, although specimens of both G. palpalis and G. tackinoides were 

 taken, t 



Trypanosomiasis. 



It is a fortunate circumstance that sleeping sickness does not appear to occur in 

 an epidemic form in Northern Nigeria, in spite of the fact that tsetse-flies are 

 very generally distributed over the Protectorate. Sporadic cases have been 

 reported from a number of localities, and certain districts, as, for example, the 

 province of Kabba, appear to be endemic centres of the disease. In Ilorin 

 province, human trypanosomiasis is either very rare or altogether absent. The 

 missionaries both at Shonga and Patigi, however, have reported cases of a fatal 

 disease characterised by enlargement of the cervical glands and lethargy which 

 may have been sleeping sickness. The presence of the trypanosome has not been 

 demonstrated, and until this has been done it would be rash to make a definite 

 diagnosis. Elsewhere in the province the disease is unknown, and no cases of 

 even a suspicious nature came under my notice during the nine and a half months 

 I was in Ilorin. This may be due to the fact that the native population is 

 relatively immune to the disease, or to the absence of the species of trypanosome 

 (T. gamhiense and T. rhodesiense) which are pathogenic to man. The comparative 

 scarcity of game, which has been proved by Kinghorn and Yorke to be the 

 reservoir of the sleeping sickness parasite in Rhodesia, should also be remembered 

 in considering this subject. There is indeed some reason to believe that the 

 native population is less susceptible to trypanosomiasis in West Africa than it is 

 in other parts of the continent. Such an opinion has been expressed with regard 

 to sleeping sickness on the Gold Coast, and the few cases of the disease that I 

 have met with in Northern Nigeria have been isolated instances occurring in 

 districts in which the whole population was exposed to the attacks of innumerable 

 tsetse-flies. In the opening up of the country it is, however, of the greatest 

 importance to guard against the possible spread of sleeping sickness ; for every 

 development is accompanied by the introduction of individuals, both Europeans 

 and natives r who are certainly not immune. As has already been pointed out, 

 Ilorin occupies a somewhat precarious position from its proximity to Kabba. It 



* "A third report on experimental work on Animal Trypanosomiasis," by H. Andrew Foy, 

 D.P.H., in the Journal of Tropical Medicine & Hygiene, 16th Oct. 1911. 

 f Annals of Tropical Medicine and Parasitology, 1913, vii., no. 1, 

 + Ibid. 



29262 B 



