CO885-(21-23) — Page 567

PUBLIC RECORD OFFICE

Reference :-

C.O. 885

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ALLY WITHOUT PERMISSION OF THE BE REPRODUCED PHOTOGRAPHIC- COPYRIGHT PHOTOGRAPH-NOT TO

PUBLIC RECORD OFFICE, LONDON

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Morsitans were met in fair numbers all along this overgrown part from within a mile of Nakasongola itself. In the open part of the road from the tenth mile or so to the lake fly were not seen when going along in the ordinary way; the road is very wide and was cleared over its whole width. Morsitans were, however, observed in places in the grass and bush at the side of the road.

About half-an-hour was spent in the canoe at the port itself, but although hæmotopota and a tabanus species were seen, morsitans was not observed. The fly in Buruli, as far as I was able to observe, is not congregated into thickly-infested belts as in the Masindi district. Its efficiency as carrier of disease is, however, not diminished on that account.

Kichwabujinjo was visited and cattle trypanosomiasis was found at Kisenye; the disease seemed fairly recent and the Gomboloa chief had a herd of 200 which seemed unaffected, but they were not examined microscopically. 1910 was given as the date at which the disease had first been observed here. I was told that the disease was present in the Kinyomosi district along the Sesebwa River, but did not go there to investigate details.

Following down the Nakasongola-Bombo road to Katugo, I was told that cattle were kept safely in the Kiunga district immediately south of Kinyomosi. The country is very fairly well cultivated and the cattle are owned by peasants, who have sown cotton, and the money derived from this industry is converted into cattle. The herds are very small and the cattle are pastured beside the villages, each man's family herding his own animals; they spend the night either in special houses built for them or simply inside the fence beside the house of the owner. collections of cattle have been maintained successfully since 1898.

These small

I did not examine these herds, but the account given agreed so exactly with what I had myself observed among the peasant population in the Kibona district of the Northern Province that I have no doubt that the statement of conditions is in accordance with the facts. In the Kibona district this method of herding was attended with a like success in avoiding disease. Both cases bear out the idea that cultivated areas even in suitable districts seem to keep pretty free from tsetse diseases.

The

It is of importance to note that the whole of this investigation leads to the conclusion that, owing to the absence of proper and perfectly simple precautions in regard to the moving of herds, well over 3,000 head of cattle have been lost to the Protectorate, and the whole country from the middle of the Saza of Bulimwesa in Buganda to the Hoima-Masindi road and the Budongo forest in the Northern Province has been rendered permanently unfit for the pasturing of herds. permanence of the condition is dependent on the large quantity of game which exists all through the country in question and which acts as a reservoir for the infections under consideration. It may be pointed out in passing that it is the game, as distinct from the small mammals, that are exclusively responsible for the natural maintenance of such trypanosomes as T. vivax, T. nanum, and T. uniforme.

It is scarcely necessary to reiterate that the process of dissemination described above is precisely the method by which human as well as animal trypanosomiasis spreads, and the whole of this area, which is only now, with the advance of cotton- growing and the consequent increase of traffic, being seriously opened up, is an admirably receptive environment for the fostering and dissemination of human trypanosomes carried by Glossina morsitans.

From the very clear evidence obtained in the Masindi district one may practi- cally deduce the presence of Glossinidæ from the incidence of endemic cattle trypano- somiasis. Disease appearing in two consecutive years in one district may be taken as evidence of an endemic focus for administrative purposes. Owing to the curiously widespread and diffuse distribution of tsetse in Buruli, and in the bush country in the north of Bulimwesi, and the absence of clearly-defined belts of fly, this tract of country up to the Kafu is exceedingly difficult to control.

Moreover, human trypanosomiasis might easily advance fairly rapidly through Cases would this country without attracting the attention of European officials. appear sporadically throughout the country in question, and as our knowledge of the detailed health conditions of the native population in the outlying districts is still very slight, the advance of the disease would easily escape detection.

In the Buruli district the danger to human life would probably be insignificant, as human contact with fly seems to be relatively slight. It is, however, just exactly districts of this type that form such dangerous links in connecting up parts of the country where the risk to human life would be extremely serious.

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The balance of parasitism between tsetse trypanosomes and the wild game has achieved what may be considered the biological ideal, viz., complete toleration on the part of the vertebrate and very efficient transmission on the part of the carrier. The rash incursion of man and his domestic animals into this well-balanced arrange- ment is an unfortunate circumstance from the human point of view, but is an utterly unimportant incident in the biological economy of Africa at large. Therefore, little hope can be held out that these trypanosome diseases will become less deadly to man within any relevant period of time, as the endemic value of virulence has already been arrived at independently of man as a host. It is on this account that every reasonable and consistent effort should be made to get some control of the con- ditions before the species detrimental to human life shall have become established beyond eradication.

In considering the advance of trypanosomiasis it must be remembered that commerce and the resultant increase in traffic, the moving of population and domestic animals, military operations and their attendant circumstance, all tend to break down the natural barriers, and may carry the organism in a single year across a tract of country which under other conditions might have acted as an efficient barrier for generations. Such an unfortunate transgression of a natural limit seems un- doubtedly to have occurred when the Baganda cattle were taken to Buruli over the ridge of hills and through the wide belt of elephant grass and cultivated fly-free lands which stretch across south Bulimwesi towards Mubendi.

At present the north of Bulimwesi and the whole of Buruli would pass a human trypanosome carried by G. morsitans in a few years, without attracting attention, into the fly-belts round Masindi, where there would occur a serious loss of life, both native and European.

Trypanosoma rhodesiense, a species of trypanosome fatal to man eminently suitable for transmission in a morsitans country, has already appeared in German East Africa, and we have no assurance [that] the species in question is not already in Ankole. (See report of Dr. H. L. Duke's safari, 1912-1913.)

1.

General Summary.

The whole of the country from the northern part of the Saza of Bulimwesi right up to the Hoima-Masindi Road and the Budongo Forest must now be looked upon as an area permanently infected with cattle trypanosomiasis. This vast tract, which includes the whole Saza of Buruli, including the bush country to the west of the Lugogo River (Butengesa, Kijogolo, and Kijaguso), has become infected within the last ten to thirteen years from the central focus of the Nakasongola District.

2. The origin of this whole infection can be traced to the moving of large herds of cattle from the south, south-west, and south-east into the Nakasongola District in 1900. These cattle were moved into this morsitans-ridden country without being subjected to any examination whatsoever.

3. The disease was carried north of the Kafu by the moving of a single infected herd from Nakitoma, in Buruli, to Kibangaya, in the Northern Province, in the year

1906.

4. The whole of the area aforesaid must be looked upon as morsitans country. This fly, Glossina morsitans, is responsible for the spread of the disease in question. Morsitans extends over large areas beyond the recognised fly-belts; the distribution varies greatly according to the season of the year, the fly invading a very much wider area during the wet months.

5. The percentage of infected flies in the Masindi fly-belt, which crosses the Masindi Port Road, is 10 per cent., an amazingly high figure. This has been produced in the space of six years.

(See report for evidence.)

6. Trypanosomiasis of all kinds (human and animal) could be stamped out. entirely and permanently from any district within two years were it not for the game reservoir. It is important to note in this connection that the cattle trypanosome, T. virar, the species which has travelled the most rapidly through this district, is unable to survive in any but the large domestic animals (cattle and goats) and the big game.

7. All trypanosomes of the Gambiense group (i.e., T. gambiense, T. brucei, and T. rhodesiense) introduced into any part of this country, which extends from Bulim-

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