# Transactions of the Royal Society of Tropical Medicine and Hygiene, volume 1/Demonstration of Oriental Sore and its Parasite

DEMONSTRATION OF ORIENTAL SORE AND ITS PARASITE.
By Sir PATRICK MANSON, K.C.M.G., M.D., F.R.S.
(Friday, November 15th, 1907.)
Sir Patrick Manson said that, fortunately, he had an opportunity of demonstrating a typical example of the sore, which was variously known by several names, such as Delhi boil, Bouton d'Aleppo, etc. That this was a case of the disease had been proved by the microscope, which showed the characteristic parasite in enormous profusion. The Society was deeply indebted to the patient, himself a medical man, for his complacency and courtesy in having come there at much inconvenience to himself, and not without considerable suffering. He was a medical man, of about forty-one years of age, and had been working in Palestine for a considerable period. In June last he had to go to Baghdad, where he remained for nine months. On his return, and while at sea, some three weeks after he left that city, he saw what he thought was a mosquito bite on the back of his left hand : it was deep red, irritable, and itchy. Similar papules appeared at the same time on the dorsum of his left foot, and on the front of his right shin; they were dry and scaly, and gradually the scurf and scales accumulated, and, mixing with exuding lymph, hardened into crusts. After several weeks the crusts fell off, leaving a superficial ulcerated surface, which had an indurated base and elevated edges. This sore extended until it was 2 in. in diameter, when fungating granulations sprang up almost completely covering the eroded surfaces and preventing healing ; but recently these granulations had be​come dropsical and atrophied, and attempts at true cicatrisation had now begun to appear. That was to say, the disease had reached its final stage after lasting nine or ten months.
There were many interesting points in the history, the features, and the affinities of Oriental sore. First, it was protective against itself when it had run its course, the patient obtaining in most instances permanent immunity against the disease. Another characteristic was the uncertainty of the incubation period, which was sometimes short, so much so as to be almost an immediate sequence of infection and sore, in other instances running into many months. A lady missionary from Delhi whom he had recently seen developed Oriental sore in the South of France, five months after she had left the place of infection, and that circumstance, viewed in connection with immunity, was an interesting and important feature. Still another point of interest was that the disease occurred almost invariably on exposed parts of the body—on parts that were not generally covered by clothes—and that would lead to the inference that infection took place by some animal which could readily attack exposed parts. Insects, such as bugs and fleas, were thus ruled out, but mosquitoes and flies, for instance, might be effective carriers, as they were likely to convey it only to exposed places.
The disease, too, was inoculable. He himself had not been successful in inoculation experiments; but there was no doubt about inoculability. Apart from his own experience, that had been abundantly confirmed. Dr. Daniels, who was not likely to fail when care and dexterity in manipulation were required, had, however, made many inoculations with him without success, and he thought he had a good explanation for their failure. They had not succeeded in the experiments which they made upon dogs, rabbits, monkeys, and sheep, because the parasite of the ​disease had passed the active stage, and was in an involuted or morbid condition. That, no doubt, too, was the explanation of the results which had recently been published by James. Deputed by the Indian Government to investigate the connection between the parasite discovered by Wright and the disease, Major James found, in Delhi, that only in a certain proportion of cases could he find in the scrapings of sores the characteristic organism. In many cases of undoubted Oriental sore, it was absent. As regarded the patient that evening, that too was the condition; whereas at first there were swarms of parasites crowding the cells and tissues, now they were extremely rare and difficult to find, and there could be little doubt but that these organisms were in the involution stage. But this mysterious malady had a still more interesting and note-worthy feature than all these. That was the relationship of Oriental sore to the deadly disease kala-azar. Per se, Oriental sore did not endanger life; though protracted, the tendency was to cure, and we could inoculate it without apprehension of serious evil. Kala-azar, on the contrary, never healed; it was most invariably fatal; and it would be, therefore, entirely unjustifiable to inoculate kala-azar into any human being. Yet the parasite of Oriental sore and the parasite of kala-azar were, so far as could be seen with the microscope, identical. He said morphologically, but perhaps not biologically, identical. And this fact gave rise to many questions and speculations. Were they of the same species In their relations there was a unique opportunity of investigation, and perhaps of discovery. Of the connection between the Leishman-Donovan body and Oriental sore on the one hand, and kala-azar on the other, there could be little doubt; but it was only by successful inoculation experiments that the information about kala-azar, of which they stood so much in need, could be obtained. Assuming that the parasites were absolutely ​identical, as Oriental sore immunised against itself it ought also to immunise against kala-azar. An opportunity to test that had recently presented itself at the School of Tropical Medicine. They had, in hospital, a case of Oriental sore, and at the same time a case of kala-azar, and he had been able to obtain the consent of the patient who was suffering from kala-azar to be inoculated with Oriental sore. Two students of the school volunteering to act as controls of the virulence of the inoculated matter were inoculated at the same time, but the result was failure; none of the inoculations took. Still, he would much like to get another opportunity to repeat that inter- esting experiment with an Oriental sore in an earlier stage. It was essential that one should have a thoroughly reliable virus, and at the same time a suitable case of kala-azar. The former he was endeavouring to start and keep going, by means of monkeys, etc.; the latter would, no doubt, in time present itself. If any who were present that evening could assist him with an opportunity, or avail themselves of an opportunity to test this hypothesis, the result, he believed, might encourage them to continue in a new line the attempts now being made to find a cure for kala-azar.
Again, was Oriental sore constitutional; was it a systemic disease; or was it one that, if the local lesion were cut out or destroyed, would thereby be cured? He considered that Oriental sore was a general infection, and that was probable, because, for one thing, a patient, on obtaining immunity, obtained general immunity. If the active sore was eradicated in one place, it would appear in another, and it could only be effectively cured when the parasite had run its course and reached the involution stage.
Discussion.
Dr. G. C. Low asked if spirochaetae had been looked for in any cultures which had been made from Oriental sore. A pathological parallel was the parasite of ulcerating granuloma, for an organism which was either identical with that, or very like it, had been shown to occur in specific venereal sore, though it was not supposed to have a pathogenic function. The trend of opinion was indeed that all diseases of the granuloma type were due to spirochaetae, and he regarded it as at least probable that Oriental sore might safely be included in that category. It was not, he thought, proved that the parasite shown that evening was pathogenic of Oriental sore; it was perhaps only an extraneous parasite which had found a suitable medium. Sir Patrick Manson had not touched on the geographical distribution of kala-azar and Oriental sore, but an important point was that they did not correspond in that respect.
Lieutenant-Colonel Duncan said that he had been very much impressed by the success of a native remedy for Oriental sore on the northern frontier of India. He had seen more than one case, which had resisted hospital treatment for months, cured by the application, with pressure, of a flattened rifle-bullet cut to the shape of the sore.
Dr. Sambon said that formerly Oriental sore was considered merely a local disease, but the evidence was rapidly accumulating that it was constitutional. Immunity, he might say, did not preclude the possibility of relapse of a disease. Like malaria. Oriental sore might relapse even though immunity was being established by its own process. It should be borne in mind that exposure of the part was found to correspond with the lesion in other tropical diseases, such as pellagra, but a further and more important ​peculiarity of Oriental sore was that it was frequently restricted to towns, country districts being free. He thought flies were scientifically, as well as popularly, incriminated; Oriental sore was locally called "fly disease," and it was known that parasites of the group to which the Leishman-Donovan belonged were often carried by flies, not merely suctorial flies, but also non-biting species. Leishman-Donovan, too, had been found in a sore on a dog, which to the eye, and to the microscope, was exactly similar to the Oriental sore of man, and it had been found many times in horses.
Dr. Hartigan thought Sir Patrick Manson had laid a little too much stress on exposure, because he had seen quite as many cases of Oriental sore on non-exposed parts as exposed parts.
Dr. Fremantle pointed out that the evidence for constitutional kala-azar was not strengthened by the theory of exposure; that indicated merely a local inoculation. The patient said that when sores appeared on his feet, he had been walking about in sandals, with bare legs, and it might be that this infection was, therefore, merely local, and akin to the granulomata met with in dissecting-room porters and other people who handled cadaveric material—an infection which, by the way, much resembled Oriental sore in other characteristics.
Dr. Newham asked whether the Finsen light or X-rays had been tried as a means of treatment?
Dr. MacDonald said he had seen a good deal of the disease in North Queensland, and he had believed it might be due to the bites of the small jungle leeches which, in such excessive numbers, infested most tropical forests. The Queensland sores were mostly on the face; oftenest on the nose and upper lip. He had seen them also on the arms. ​The bites of the leeches, he thought, had a constitutional effect, and the disorder much resembled a disease met with in horses in Queensland, which was known as swamp cancer.
Dr. Frederick Johnson (the patient) said that at Baghdad, though most of the native children had the disease, the people were completely indifferent to it, and no steps were taken for its cure from beginning to end. They were equally indifferent as to the prevention of infection.
Sir Patrick Manson, in reply, said that Dr. Low's question as to whether the parasite was the actual cause of the disease was difficult of complete answer. The solution and proof was obviously to be obtained only by getting the parasite in pure culture, and then finding the insect medium by which it was conveyed. In the meantime, as parasitic growth was extraordinary, and as every endothelial cell was crowded with parasites seen in no other disease, it forced itself upon their belief, and they were justified in assuming, that they must be causative. As to spirochaetse, no doubt, after search, plenty of spirochaetse would be found in the tissue and discharges. They had been found in ulcerating granuloma by Wise in British Guiana, but investigators would get no nearer a solution in that way, on account of the difficulty of determining the relationship of any special spirochaeta to the disease in which it was found. He had tried and failed to cultivate the parasite, because he could not keep his cultures sterile, and as they knew, bacterial growth was absolutely fatal to the kala-azar parasite. As to the distribution, kala-azar, it was well known, was a disease of low-lying riverine districts, and Oriental sore a disorder of dry, sandy countries; it was difficult to reconcile this with identity of the parasites, and in the meantime, he had no explanation to offer. Treatment by lead compress would be followed by ​cure if the parasite had reached the involution stage; it would be useless, he believed, if the parasite was still active. As to Dr. Sambon's mention of recurrence, he did not recollect having seen reports of any such cases; but it was now believed that diagnosis of Oriental sore must be verified by the microscope. [Dr. Sambon here stated that the cases were reported by Dr. Vandyke Carter.] Perhaps the explanation of the fact that Oriental sore was often a town disease was that there is a large number of pariah dogs in many Eastern cities, and they are extremely liable to the disease. With regard to what Dr. Fremantle said, the lesion might be local, but the disease general; they had not to go far to seek parallels, for syphilis was one. As to the X-rays and Finsen-light treatment, he remembered one case of Oriental sore which had been diagnosed as lupus, and treated by X-rays with disastrous results. Severe inflammation had set in, and the patient's condition was much aggravated. Leeches, he thought, as suggested by Dr. MacDonald, could not transmit Oriental sore. There were no leeches in the sandy districts where Oriental sore was so prevalent; but it might be difiierent with regard to kala-azar, which preferred damp, jungly, alluvial districts as areas of prevalence.