PUBLIC RECORD OFFICE
Reference :-
wwi mi C.O. 885
22 PUBLIC RECORD OFFICE, LONDON
ALLY WITHOUT PERMISSION OF THE BE REPRODUCED PHOTOGRAPHIC:]
COPYRIGHT PHOTOGRAPH—NOT TO
12
RESULTS OF THE EXAMINATION OF WILD ANIMALS FOR DISEASE-PRODUCING TRYPANO- SOMES BY DRS. KINGHORN AND YORKE IN RHODESIA.
11
Antelopes.
Non-antelopes.
Kudu (4)
7 animals examined.
Zebra
Waterbuck (29)
55
Warthog (1)
22 animals examined. 21
"1
Bushbuck (6) ..
9
15
"
Rhinoceros
7
"}
Eland (4)
15
Buffalo
6
"
Roan (2)
13
*
31
Hartebeest (1)
14
M
"
Puku (2)
18
"
"
Mpala (2)
29
Genet
♫
31
Sitatunga (1)
2
Lion
"
+1
Duiker (2)
9
11
}
Klipspringer
2
"
Reedbuck
19
"1
Wildebeest
21
NONNN
Total
177
Bushpig Hyæna
Caracal
4
2 no
2
Elephant
Hippopotamus
Hunting dog
Giant rat Squirrel Galago
23
+1
inoculation.
J
2
23
11
1
1 no inoculation.
1
1 no inoculation.
1
>
1
11
Total
74
Wild rats Monkeys Wild mice
142 no inoculation. 256
31
15 "
12
The number in brackets following the name denotes the number of infected individuals. Where there is no number no trypanosomes were found. All trypano- somes causing disease in man or domestic animals are included.
March 13th, 1913.
9811
No. 14.
MEMORANDUM.
A. G. BAGSHAWE.
DOMESTIC ANIMALS AS RESERVOIRS OF TRYPANOSOMES.
It is generally known to those conversant with the subject that the domestic animals which live in close association with man in Africa, namely, cattle, sheep and goats, and dogs, may harbour trypanosomes which are lethal to other domestic animals or to man himself without themselves showing any evidence of disease. Probably in all these cases the animals in question have lived long in contact with tsetse fly and have, like the game, acquired a tolerance for the trypanosomes conveyed by them. I am not aware that the recorded observations have ever been collated. I have here briefly given a sample of the evidence that the domestic animals act as reservoirs of these trypanosomes; to collect all the observations would take more time than is at my disposal.
Domestic animals as reservoirs of T. gambiense.
Dogs-GREIC, who visited a sleeping sickness area near Lake Albert, Uganda, in 1904, found that many dogs were dying of a wasting disease. Two were sent to the laboratory three weeks' journey away. They were thin but had no symptom of disease. They died from worms two months later. A trypanosome not dis- tinguishable from T. gambiense was found in them, and a dog inoculated from one of them lived seven months and died with the brain lesions characteristic of sleeping sickness.*
Cattle. BRUCE and the other members of the Sleeping Sickness Commission in Uganda infected cattle by causing G. palpalis naturally infected with T. gam- biense to feed upon them. Afterwards clean flies were fed on these cattle, became
Report of the Sleeping Sickness Commission, Royal Society, No. 8, p. 64.
13
infected from their blood, and transmitted the infection to other animals by biting. Moreover, of 17 cattle examined in the sleeping sickness area one was found to harbour T. gambiense; it was apparently healthy.*
Sheep and goats.-KLEINE and FISCHER, on Lake Tanganyika, in German East Africa, infected several sheep and goats by causing G. palpalis infected with T. gambiense to feed on them, and in three instances clean flies became infected from these animals and transmitted the infection to others. The blood of the sheep and goats was infective to fly for 90 days.†
French observers have succeeded in infecting domestic fowls with T. gambiense. There is at present, however, no evidence that these animals become infected in nature.
Domestic animals as reservoirs of other trypanosomes lethal to stock. DUTTON, TODD, and KINGHORN, in 1903-1905, made a study of cattle trypano- somiasis in the Congo State. They write as follows:-
44
At Kasongo trypanosomes were seen in 5 per cent. of cattle. The percentage actually infected is certainly much larger; yet this herd is in- creasing. There were no deaths in it from disease during our stay at Kasongo, and the cattle were in splendid condition.
"
Trypanosomiasis is common and often fatal among Gambian horses. But two horses in the Gambia found to be infected with Trypanosoma dimorphon in December, 1902, were still alive, apparently healthy, and were constantly worked in November, 1906
As will be gathered from the notes on the animals present at various posts in the Congo [details are given elsewhere in the paper] individual cattle, horses, &c., seem to be resistant, since they live for some years in places where the disease is of a very severe type. Cattle are susceptible to inoculation with Trypanosoma dimorphon, yet at many places in the Gambia, at Cape St. Mary for example, large herds of cattle in splendid condition graze over the same ground as the horses
"From all these facts it is not unreasonable to suppose that, like the game, domesticated animals may thrive in spite of actual trypanosome infec- tion and exposure to constant re-infection."
Sheep and goats.-MONTGOMERY and KINGHORN, in 1907-1909, in North- Eastern Rhodesia, found sheep and goats regarded by both Europeans and natives as immune. These animals, three and a half months after the diagnosis of the natural infection, were in as good condition as at first and not suspected of sickness by the owners. They write:-
"
Speaking broadly, trypanosomes were generally visible in the peri- pheral blood, both in naturally and experimentally infected animals, and being apparently in good health, it appears to us that they may act as reser- voirs par excellence for the virus, and by trade and movement may become dangerous potential disseminators of the disease."§
PECAUD, in Dahomey, studied the trypanosome infections of the smaller domestic animals. About a dozen infected sheep and goats were kept under observa- tion for five to six months; all appeared to be in perfect health. He thinks these animals must serve as reservoirs, especially as wild animals are rare in the region in which his observations were made.
Goat.-DUKE, in Uganda, kept at the Mpumu laboratory a goat naturally infected with T. nanum. Seven months after arrival it was in excellent health, trypanosomes being visible in its blood at rare intervals.¶
•
Cattle.-POLLARD, in Northern Nigeria, writes as follows:-
There is in the Munshi division, and in the northern part of the Province, a small black breed of cattle, which is apparently immune to tsetse.
At any rate, these cattle can be kept in the Munshi district where no horse
Report of the Sleeping Sickness Commission, Royal Society, No. 11, p. 71.
† Zeitschrift für Hygiene und Infektionskrankheiten, 1911. Vol. 70, pp. 1-25.
Annals of Tropical Medicine and Parasitology, Vol. 1, p. 268.
Anuals of Tropical Medicine and Parasitology, Vol. 3, p. 335. Bulletin de la Société de Pathologie Exotique, 1909. Vol. 2, p. 127. Proceedings of the Royal Society, B. Vol. 85, pp. 4-9.
I
T