Art. VI. THE SLEEPING SICKNESS.

1. Preliminary Notes on Sleeping Sickness. By R. U Moffat, Principal Medical Officer, Uganda Protectorate. Submitted by Commissioner Sadler to the Marquess of Lansdowne, 1902. (Foreign Office Papers: East Africa.) 2. Reports of the Sleeping-sickness Commission of the Royal Society. Nos I to IV. London: Harrison, 1903. 3. A Monograph of the Tsetse Flies. By E. E. Austen. Published by order of the Trustees of the British Museum. 1903.

4. Generations- und Wirthswechsel bei Trypanosoma und Spirochate. Von Fritz Schaudinn. Arbeiten aus der Kaiserl. Gesundheitsamte zu Berlin; vol. xx, part 3. 1904.

AMONG the strange and mysterious diseases to which mankind is subject in regions less familiar to the civilised world than Western Europe, none is stranger or more appalling in its quiet, inexorable deadliness than the Sleeping Sickness of the West African coast. Apparently it has existed among the natives of that region from time immemorial; but the first printed record we have of it is due to Winterbottom, who, writing in 1803 of Sierra Leone, said, The Africans are very subject to a species of lethargy which they are much afraid of, as it proves fatal in every instance.' One of the latest notices of the disease, before it became the subject of active investigation within the last two years, is that of Miss Kingsley, who saw a few cases near the Congo estuary; but, though she was impressed by the mysterious fatality of the disease, she did not describe it as very prevalent or as a general source of danger to life. The opening up of the Congo basin and increased familiarity with the inner lands of the West African coast have shown that this disease is widely scattered-though rarely so abundant as to be a serious scourge-through the whole of tropical West Africa. Writers in the early part of the last century described the disease as occurring in the West Indies and in Brazil. Its presence was almost certainly due, in those days of the slave trade, to the importation of negroes already infected with the disease; and a Vol. 200.-No. 399,

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curious theory obtained some favour, according to which the sleeping sickness of the West Indian slaves was a kind of nostalgia, and, in fact, the manifestation of what is sometimes called a broken heart.'

The signs that a patient has contracted the disease are very obvious at an early stage. They are recognised by the black people, and the certainly fatal issue accepted with calm acquiescence. The usually intelligent expression of the healthy negro is replaced by a dull apathetic appearance; and there is a varying amount of fever and headache. This may last for some weeks, but is followed more or less rapidly by a difficulty in locomotion and speech, a trembling of the tongue and hands. There is increased fever and constant drowsiness, from which the patient is roused only to take food. At last usually after some three or four months of illness -complete somnolence sets in; no food is taken; the body becomes emaciated and ulcerated; and the victim dies in a state of coma. The course of the disease, from the time when the apathetic stage is first noticed, may last from two to twelve months.

It is this terrible disease which has lately appeared on the shores of the Victoria Nyanza, in the kingdom of Uganda, administered by the British Government. Until the early part of the year 1901 there was not the slightest suspicion that sleeping sickness occurred in any part of the Uganda Protectorate; nor was it known in East Africa at all, any more than in the north and south of that great continent. It seems gradually to have crept up the newly opened trade-routes of the Congo basin, and thence to have spread into the west of Uganda, the territory known as Busoga. Numbers of Soudanese and Congo men are known to have settled in this region after the death of Emin Pasha. First noticed in 1901, it was estimated in June 1902, by the Commissioner of Uganda, writing officially to the Marquess of Lansdowne, that 20,000 persons had died of this disease in the district of Busoga alone, and several thousands in the more eastern portion of Uganda. At this moment (June 1904) it is probable that the number of deaths in this region due to sleeping sickness since 1901 amounts to more than 100,000; and this though, most fortunately, the disease has not yet spread eastward from Uganda

into British East Africa,* nor, so far as has been reported, down the Nile. No curative treatment for the disease has yet been discovered; nor is there any authenticated instance of recovery.

The appalling mortality produced by this disease in Central Africa naturally caused the greatest anxiety to his Majesty's Government, which had but just completed the railway from the East Coast to the shores of lake Victoria Nyanza, and had established a prosperous and happy rule in that densely populated region. The official medical men on the spot, though capable and experienced practitioners, were unable to cope with this new and virulent outbreak. The Foreign Office, having no imperial board of hygiene and medical administration to apply to in this country, sought the assistance of the Royal Society of London.

A committee of that society had already undertaken the study of malaria at the request of the Secretary of State for the Colonies, and had sent out young medical men as a commission to make certain enquiries and experiments on that subject and report to the committee in London. The sleeping sickness enquiry was undertaken by the same committee; but unfortunately very insufficient funds were placed at its disposal. When the South African cattle-owners found their herds threatened three years ago by a new form of mortal disease-'the East Coast fever'-the South African Government accepted the offer of Dr Robert Koch, of Berlin, to undertake the investigation of the disease and the discovery, if possible, of a remedy, for the sum of 10,000l. No such sum was at the disposal of the committee of the Royal Society. They were obliged to send out young and enterprising medical men, practically without pay or reward, to see what they could do in the way of determining the cause of, and, if possible, the remedy for, the terrible sleeping sickness raging in Uganda and destroying daily hundreds of British subjects. The committee set to work in the summer of 1902, and sent

* The disease has actually entered into the administrative area known as British East Africa, but has not made any rapid progress towards the coast. According to a recent report by Dr Wiggins, the disease is confined in British East Africa, as in Uganda, to those areas in which Glossina palpalis occurs.

out Drs Low, Christy, and Castellani to Entebbe, the capital of Uganda.

The guesses as to the cause and nature of sleeping sickness at the time when this commission set forth were very various. Some highly capable medical authorities held that it was due to poisonous food. The root of the manioc, on which the natives feed, was supposed to become infected by some poison-producing ferment. A more generally received opinion was that it was caused by a specific bacterium which invades the tissues of the brain and spinal cord. Several totally different microorganisms of this sort had been described with equal confidence by French and Portuguese investigators as the cause of the sleeping sickness studied by them in West Africa or on the Congo. Sir Patrick Manson, the head of the British Colonial medical service, an authority of great experience in tropical disease, had put forward the suggestion that the sleeping sickness was due to the infection of the patient by a minute thread-worm (allied to the 'vinegar-eels,' and one of a great class of parasites) which he had discovered in the blood of negroes and had named Filaria perstans.

The occurrence of minute worms (true worms, not unicellular plants or protozoa) in the blood of man was first made known by Dr Timothy Lewis, who described the Filaria sanguinis hominis, as well as some other most important blood-parasites, some years ago (1878), when officially engaged in an enquiry into the cause of cholera in Calcutta. Subsequently, in China, Manson found that these little blood-worms were sucked up by mosquitoes when gorging themselves on the blood of a patient. It is, indeed, difficult to imagine how they should escape passing into the mosquito with the blood. Manson suggested that the minute worms (known to be the embryos of a worm which, when adult, is about one fifteenth of an inch long) are obliged to pass through a mosquito in order to accomplish their development; but no proof of this suggestion has ever been made. We know by abundant and repeated demonstration and experiment that another blood-parasite-the malaria parasite-must pass through a mosquito, in whose body it developes, and by which it is carried to a new victim of infection. This was suspected long ago by both peasants and doctors, and

experimentally proved by Ross; but no such proof has been given of the relation of Lewis' blood-worm to a mosquito. The so-called Filaria perstans, discovered by Manson in the blood of negroes, appears to be very different from the Filaria sanguinis hominis of Lewis. It is not known how it gets into the blood; and it is very astonishing, and much to be regretted, that none of the medical men who have had it under observation have given a proper anatomical account of it. It appears that this worm is very common in the blood of negroes in tropical Africa; and, as it was found in several cases in the blood of individuals attacked by sleeping sickness, Sir Patrick Manson was justified in entertaining the view that this parasite was the cause of the disease.

One of the first results obtained by the commission sent by the Royal Society committee to Uganda was the proof-which had, indeed, been already furnished by the resident medical officers of the Uganda Protectorate-that Filaria perstans, though remarkably abundant in the blood of the negroes of Uganda, can have nothing to do with sleeping sickness, since, though it often occurs in persons attacked with that disease, it also exists in districts where sleeping sickness is unknown; and, further, many cases of sleeping sickness have been observed in which no Filaria perstans has been discovered in the blood or other parts of the body.

While Drs Low and Christy occupied themselves with settling this question as to the connexion of Filaria perstans with the disease, and carried out a careful study of its clinical aspects, Dr Castellani examined the brain and spinal cord of those who died from sleeping sickness, for bacteria. He found again and again an extremely minute globular vegetable parasite-of the kind known as streptococcus-which he concluded to be the cause of the disease, although he had not produced the disease experimentally by inoculating an animal with this microbe.

In the early part of 1903 these were the only results obtained by some six months' work of the medical meu sent out by the Royal Society's committee; and it was felt that something more must be done. The investigation of a disease hitherto little known and studied is one of the most difficult tasks in the world, requiring the highest scientific qualities. Any serious attempt to deal with the