Tropical Diseases – 7564
Dr WA Lamborn to Colonial Office (Received 30 April 1917)
(No 1) Littlemore, near Oxford, 8 February 1917
I have the honour now to submit, as requested, a report on my entomological work while under the direction of the military authorities in East Africa.
2. I reached Kilindini from Nyasaland in late March 1916, and was forthwith sent to Taveta, a military base, assurance being given that my military position would then be defined. However, I found no one in authority there having any knowledge of me; and my position, that of the only civilian at an enormous military base, being absolutely untenable, I proceeded to Nairobi, on the advice of the Base Commandant, and reported myself to the Deputy Director of Veterinary Services, who, on my pointing out the entire impracticability of attempting to do any work in the field as a civilian, informed me that the matter had not rested with the local military authorities, for instructions had been given by the War Office that Iw as not to be afforded military rank.
Towards the end of the month the matter was rectified, and on 28 April I set out once again, this time with honorary rank as captain in the East African Veterinary Corps, having instructions to report to the Assistant Director of Veterinary Services at Himo. By him I was referred to the General Headquarters Staff at Moshi, in German East Africa, where I arrived on 2 May.
3. Having examined for tsetse-flies a horse camp in the vicinity, where I found none, I was instructed on 6 May to survey for tsetse-flies the road running from Moshi to Arusha, a stretch of some ninety miles.
The march proved an interesting one as for two days the path ran through the rich farming districts and fertile woodland along the southern slopes of Kilimanjaro, then for a day across grassy plains, and finally through the rich farming country about Meru, with vegetation so luxuriant and dense as to recall to one’s mind the real tropical forest of the West African coast.
Though the intelligence notes reported the flies in the neighbourhood of Kikafu, they were nowhere found along this road, the probable explanation being that they had been confused with Haematopota, three species of which were not uncommon.
On reporting my arrival at Arusha I was instructed to return along the same road to Sanja River and to survey for tsetses a new track made to Lolkissale, sixty miles to the south-west.
After a few days’ delay owing to difficulty in obtaining provisions, I got back to Sanja River on 18th, and, having marched over eighteen miles of the Masai steppes, plain country, reached the K-D River camp (Kikuletwa Darjama River), in the neighbourhood of Noisinak Bridge, 3,5000 feet, at about 8 p.m. on a bright moonlight night. The locality, thin woodland, constituted mainly by thorn bushes seemed a very likely one for tsetses, and my expectations proved correct, for I managed to secure one of two insects that then bit me, which proved to be the female pallidipes; and I heard other tsetses round my carriers.
The camp was used as an outspanning station for the ox convoys, and I surveyed the district carefully, notifying the Deputy Director of Veterinary Services that pallidipes occurred along the road at about three miles north-east of the camp for a stretch of about three-quarters of a mile, and thereafter for three-and-a-half miles parallel to the road in the bush to the north; and I pointed out, in my report of 24 May, that, with a small amount of clearing at one point and a little deviation of the track to the south, the chances of the animals being infected would be minimized. I suggested also that they should be grazed well to the south of the road.
I returned to this route some weeks later, on 27 June, and here transcribe a copy of the further memorandum I then felt it necessary to submit to the authorities, seeing that, so far as I could ascertain, no action in regard to my report had been taken.
(No 10) 1 July 1916
On my return journey between Lolkissale and Sanja River I found two convoys, and several span of oxen drawing regimental wagons,* outspanned north of the road in the neighbourhood of the K-D River camp, and fully half of the cattle feeding well in the bush, which, as I have already remarked (memorandum of 24 May, paragraph 1), is infested with the tsetse-fly Glossina pallidipes. I saw many of the flies on the beasts and caught a number. Under these circumstances it can hardly be wondered at if the incidence of fly disease is extremely high; and as the flies have now had every opportunity of becoming infected with trypanosomes, there is likely to be an ever-increasing loss. The present loss, whatever the cause – and it is probably largely fly – seem to be great; for one officer in charge of a convoy informed me that about sixty beasts out of a total of some seven hundred and fifty in his charge drop out in each trip of nine days; and two other officers estimated that their respective losses amount to from thirty to forty animals on each trip.
* probably two thousand oxen in all
‘None of the three officers was definitely aware of the presence of flies, though each had suspected it form the restlessness of the horses.’
4. Continuing the march to Lolkissale, I reached, on 21 May, the Muruangoin River camp, 3,550 feet, having met with a few Glossina morsitans two miles north east of it, and thereafter I found them in increasing numbers for as far as three miles south of it. The camp itself, which had been until lately an outspanning station, swarmed with the flies; but, though the Commandant, a Colonel in the Indian Army, and his officers had been much bitten, they had not realized the nature of their assailants. Fortunately, at this point a new deviation of the road had been made through the more open country, and it was only necessary to point out that the convoy beasts had passed through and all the battery mules of the particular regiment then in camp, were probably infected.
On 22 May I reached the drift at the junction of the Muruangoin and Seenje Rivers, and, in traversing woodland for seven miles to the south again, met with morsitans in small numbers; and I recommended that the convoys should travel through this area at night.
Thereafter, all the way to Lolkissale, a distance of eighteen miles, at an elevation of 4,000 to 4,850 feet, a few scattered flies were met with. I was of opinion that these had probably travelled with the transport, the thinly wooded country with large open tracts, and the elevation not being, so far as one has been able to judge, conditions such as are especially favoured by the species. The fly, moreover, was certainly more numerous along this section on my return journey a few weeks later.
On 23 May I reached Lolkissale, and on 27th received instructions to proceed in search of tsetses along the road as far as Ufiomi. For thirty-seven miles of more or less open country no flies were encountered, but thereafter, to mile forty-four, at the Tarengere River, 4,000 feet, morsitans was fairly abundant.
It was necessary then to point out that, though to the south of the river there was a very considerable plain and good grazing, it was the practice to outspan animals on both sides, even among the thorn bushes on the north side infested with the flies. The desirability of night travel and outspanning always to the south was duly emphasized in a report dated 1 June. Judging, however, by the large number of animals outspanned in the fly area on my return, no action could have been taken.
Along a further stretch of the road, fifteen miles, to Ufiomi, only scattered flies, probably carried by the transport from the area mentioned, were found.
5. At Ufiomi I was further instructed to survey the road for tsetses as far as Kondoa Irangi, fifty miles, a task which I completed by 10 June, finding none. I here found lively operations in progress between General van Deventer’s forces and the main German body, and as the food question was rather a pressing one, both for myself and my carriers, I was not sorry when on 17 June I received instructions to return and report myself to General Headquarters at Moshi.
Between Ufiomi and Lolkissale I travelled by a more northern route, a German track, used for many weeks by our transport, but later abandoned on account of its rough nature in favour of the more southern route by which I had come down. On this old road, for a stretch of about twenty miles, ten to the north and ten to the south of the Tarengere River, mositans swarmed and were troublesome.
6. An increasing feature the nearer one approached the actual scene of military operations was the number of dead and of ailing and discarded animals scattered along the road.
Many oxen had apparently dropped while on trek, and had been left where they fell, their bodies being crushed and their bones driven into the earth by the constant passage of motor lorries. Dead horses, too, were abundant, I counted some twenty all recently dead at Tarengere River crossing, some in the water, which latter, at my suggestion, were removed by the orders of the Camp Commandant.
In the immediate neighbourhood of Ufiomi were numbers of dead horses, mules, and donkeys, in varying stages of decomposition, so situated round the camp, in the middle f which was a large hospital, that, whatever the direction of the wind, those therein, the sick and strong alike, suffered from the effluvia. Fortunately the medical charge was just then assumed by a Major on the permanent Royal Army Medical Corps staff, who appreciated at once the necessity for radical measures, so that, on the very morning of his arrival, eighteen funeral pyres within a stone’s throw of the camp indicated the adequate disposal of as many decomposing animals.
The presence of these carcasses, and frequently the entire lack of sanitation, resulted in the appearance of enormous swarms of Muscids, which were a scourge wherever one camped, settling in great numbers on articles of food, and permitting of no rest at all by day. As to these, I reported to the Deputy Director of Veterinary Services in the following terms:-
(No 8) Solanga Camp, 8 June
I have to request you to bring to the notice of the proper authorities the following observations on the phenomenal increase of the various Muscid flies which has taken place since the advent of the dry season.
1. The common house-fly literally swarms at all camps and halts, the factors concerned being as follows: – the insect, which breeds especially in excreta, is afforded every opportunity of doing so by the insanitary state of the campaign places, especially those spots at which troops are in the habit of camping for a single night, where no latrine accommodation, either for Europeans or for the hundreds of natives, is ever provided.*
* At Ussa, a camping ground about a quarter of a mile square, on the Moshi-Arusha road, just west of Rasthauser, three hundred natives and some white troops camped during the night I was there, no latrine accommodation being provided, and I was informed, and from the state of the ground had no difficulty in believing, that no less than two thousand carriers had been there on the previous night.
In some of the fixed camps regulations as to the use of latrines do not seem to be enforced, and in others no latrine accommodation is provided for the natives, so that the immediate vicinity is foul in the extreme.**
** This was the case, for example, at New Moshi when I arrived on 2 May, some weeks after our occupation. Heavy rains were on; the drainage from the hill running into the Pangani River, from which the camp water supply was then in part drawn. As a result of a conversation I had with a sanitary officer, latrine accommodation for the natives was at once provided.
The role which the house-fly plays in the dissemination of dysentery, enteric and similar diseases has been well established.
2. The flesh fly, Sarcophaga, and the green bottles, Pyenosoma and Lucilia, which are an equal pest, breed more especially in putrescent cadavers, also feeding on the fluids thereof. This special pabulum is provided by the large numbers of dead transport animals left rotting along the roads, especially near the camps. At Tarengere, for instance, there were twenty, and at Ufiomi, until the arrival of the Royal Army Medical Corps staff, conditions were worse. From these dead animals the flies fly direct to water or settle on human foodstuffs. The further risks to health must be obvious.
3. I must take this opportunity of pointing out the fact, which obtrudes itself so forcibly on the luckless pedestrian at various camps, eg, the Masai water-hole south of Lolkissale, and at Solanga between Ufiomi and Kondoa Irangi, viz hat no attempt has been made to set apart by rail or otherwise a section of the scanty water for European use. It is the rule to find at such places the water churned up by the hoofs of the animals, and often fouled by their dejecta, or by the presence of dead animals in the immediate vicinity. ***
*** The significance of this kind of thing will appear when the history of the campaign comes to be written and the extent of our losses from dysentery is revealed.
No acknowledge of this report was received nor was there any evidence so far as I could judge, that any action was taken as a result of it. Weeks later, for instance, on 20 July, I passed at one spot on the roadside between Lushomo and Handeni no less than three hundred dead horses, the odours from which tainted the air over a very wide area, and on the following day I passed sixty-seven more at another halt.
7. I reached Moshi again on 1 July, and there received instructions to carry out three further reconnaissances for fly, a) between Ngulu Gap, in the Pare Mountains, and Same; b) between Same and German Bridge (Mabirioni); and c) between Mabirioni and Handeni, a stretch altogether of about one hundred and sixty miles.
I returned from Moshi to Mbuyuni, a base in British East Africa, by railway, mainly on the new Voi-Kahe line, and set out on foot for Ngulu Gap, which I reached on 6 July.
In the Gap itself, an elevation of 2,500 feet, and along the track for fifteen miles to the south, pallidipes literally swarmed, being more numerous, I think, than any species of the fly in any of the areas which I have traversed.
Same, on the Tanga-Moshi Railway, was reached on 10 July, no more flies being encountered; and subsequently the road, more or less closely parallel to the railway, was free. The Pangani River was then crossed and the journey continued along its west bank for three days to Lushomo, the point where the German trolley line from Mombo to Handeni crosses. Here a few scattered pallidipes were again met with, and they were taken now and again during the three following days up to a point three miles north of Handeni, 2,800 feet, which was reached on 22 July.
At Handeni the work was interrupted by an attack of dysentery following on several attacks of malaria, which kept me in various field hospitals for the greater part of a month, but I was able to report myself again for duty on 24 August.
8. On 29 August I received instructions to proceed to Tanga, and thence by first available ship to Bagamoyo,, a report being required as to fly on the Bagamoyo-Morogoro road, a section of the original Arab slave route from Tanganyika to the coast.
Bagamoyo was reached on 5 September, and I set out on trek forthwith. For five days the route ran through thin woodland interspersed with grassy slopes, on which herds of native-owned cattle were here and there dotted; but on the sixth day, two miles east of Ngerengere, an important station of Central Railway, and about a hundred miles west of Dar-es-Salaam, a thorn bush zone was entered, and moritans appeared in considerable numbers. On the following day the journey was continued to Kikesse, some fifteen miles west of Ngerengere, along a road south of the railway, along its whole length the fly was excessively annoying, pallidipes being present as well as mositans, though not so numerous, and, rather to my astonishment, a few brevipalpis, two of which, one a female, hit me at 11 a.m., the sun being very bright and hot. The bush in which the latter insects occurred was unusually dense, but so far as I could ascertain, there was no water near by.
9. Morogoro, the end of the journey, was reached on 17 September. Two days spent at Morogoro in the tsetse survey of the neighbourhood resulted in the discovery of abundant morsitans some two miles to the north of the town in the usual thorn bush country, extending back, as I was informed by transport men, for fifteen miles, throughout which the fly was reported to be troublesome.
I visited also the German Government stock farm situated about two miles south of the town and about five hundred feet up in the hills. The man in charge, a Swiss, formerly in the employ of the German Government, informed me that prior to the War the cattle had thriven there for many years, but that recently, owing, as he through, to the constant movement of troops and animals into the town through the fly area, the fly had been taken on the farm, with the result that there had been progressive loss in the stock.
10. On 19 September I received insturctions to return to Dar-es-Salaam, and attempted to do so by the old road, more or less parallel to and south of the Central Railway, along which I marched for four days, meeting on 20th with swarms of morsitans on the neighbourhood of Kanghala, about thirty miles east of Morogoro, and fifteen miles south of the railway. But the track, which had evidently not been in use for many years, became less and less defined, undergrowth having sprung up, and so I was then compelled to strick due north for the Bagamoyo road once again, along which I returned to that town; and a further two days’ trek along the thirty-six miles of coast, during which I saw no flies, brought me into Dar-es-Salaam.
11. It had become increasingly obvious that no practical value had resulted from my tsetse surveys. It was hardly to be expected that military exigencies could be modified by the presence of the flies; and moreover, by this time so great had been the losses in animals, largely, I am sure, owing to trypanosomiasis, that the bulk of the mounted men were on foot, horses were not being to any large extent replaced, and the ox convoys had (p115) almost given place to mechanical transport. I did not feel, either, that my work if continued would have any value subsequent to the War, since the fly distribution had undoubtedly been extended as a result of military movements, and would also certainly become again modified in the direction of a restriction of the fly areas when the country reverted to a more normal state of affairs. The Germans being hemmed up in a comparatively small corner of the country, and the end of the campaign within sight, I therefore tendered my resignation to the Inspector-General of Communications, under whose direct instructions I had latterly been, and who, on my discussing the position with him, agreed unreservedly with the view I expressed, so that on 17 November my resignation was accepted.
It was a lamentable reflection that so much time and energy had been wasted to so little purpose. A certain value doubtless had resulted from one’s surveys in reference to animal camps, and one’s further conclusions as to results could only have been arrived at as the outcome of the experience.
12. Facilities in regard to bionomic observations were almost entirely lacking. The following points were, however, noted:-
a) Morsitans had undoubtedly become more widely distributed along the roads as a result of military movements. It occurred, for instance, in thin bush in the neighbourhood of a large pool in the partially dried up Muruangoin River, at which, previous to the War, the Masai had been in the habit for years of watering their cattle with impunity in the dry season. It occurred sparsely, also, along the last fifteen miles from Sanja River into Lolkissale, an average elevation of 4,800 feet in more or less open country, with merely a few dwarfed trees scattered here and there, and in country of a similar character between Lushomo and Handeni. Its spread to the Government farm at Morogoro has already been commented on.
b) Such game as there might have been in the vicinity of the roads in the fly area had long since been driven away, partly doubtless owing to the constant military movements, and partly by the merciless fusillade directed against any living creature that offered a target by small irresponsible parties of men proceeding to or from the actual scene of operations. Very rarely were any animals seen even at a distance on the plains, and little spoor or other evidence of their presence was found, whether in the wet or dry season.
c) The flies in an area undoubtedly lurked more along the roadsides than elsewhere, probably attracted by the passage of moving objects, and certainly by the beasts, and they were more numerous on the return journeys than when I set out, doubtless from the constant operation of the same causes, and to some extent from an actual increase in numbers, breeding being favoured by the readily obtainable food supply.
d) Just south of the Muruangoin River one pallidipes, and one only, a male, was secured in the course of a long hunt, with numbers of morsitans.
e) Morsitans, pallidipes, and brevipalpis, the last biting by day, were taken together in one area.
f) The country in which I found large swarms of pallidipes was exactly of the same nature as that in which, from my experience in Nyasaland, I should have expected to find morsitans.
g) In two localities, seven miles north-east of the Tarengere River, and about forty-four miles south-west of Lolkissale, and again in the vicinity of the same river about ten miles to the west of this locality – probably one and the same fly area – a few morsitans were captured, which exhibited two forms of breaches of surface on the ventral aspect of the abdomen. In one case there appeared to be a minute excrescence between two of the segments; in the other a dark patch with a central depression suggested a possible puncture with dried effusion of fluid around it. Unfortunately time did not permit of a careful study of the conditions; and the scanty material which was available for examination by an expert at home has been still further reduced by the depredations of ants.
h) Morsitans pupae were found as readily as in Nyasaland, the same character of breeding place being selected by the fly.
i) In addition to tsetses, Stomoxys of various species occurred in great numbers at all camps, sometimes goading unfortunate picket animals almost to a state of frenzy, so that a watch had to be kept that, in their endeavour to get relief from the torment by rolling, they did not strangle themselves with their picket ropes. The Deputy Director (p116) of Veterinary Services was, of course, duly notified as to the presence of these flies, as the probability of the mechanical transmission of trypanosomes from infected to healthy animals was obvious.
Any adequate control of the pests was out of the question owing to the enormous quantity of dung scattered over the country, but at the veterinary hospitals and horse camps, at least, systematic attempts were made to dispose of droppings in the vicinity.
j) On the southern slopes of Kilimanjaro in May, the end of the wet season, very large numbers of dead Orthoptera, some Locustidae, but chiefly Acridians, of the genus Zonocerus, or one closely allied to it, were found in a mummified state on the plants on which they had been feeding, imagos and immature forms alike having perished. As there was no evidence of parasitism by large insects, I imagined they had probably died from some infective disease.
k) A considerable collection of insects was made, including Tabanidae, which seemed most abundant in thin woodland and plain country.
I have etc,
(Sgd) WA Lamborn
Entomologist under the Imperial Bureau
To: The Director
Imperial Bureau of Entomology