Tropical medicine

“ As with the growth of a child, we hardly appreciate the recent progress of tropical medicine, living with it, so to speak, as we do from day to day; but if we come from abroad after an absence of years, or if we compare the state of knowledge, say, of twenty years ago with that of to-day, we shall find that the stripling has not only altered in feature, but has grown into a veritable giant. ”

“ F.R.C.S., LL.D., Sc.D., M.D., F.R.S., professor of tropical sanitation, University of Liverpool and Liverpool School of Tropical Medicine; physician for tropical diseases, King's College Hospital; member of many sanitary committees; commenced special study of malaria in 1892 and later definitely traced the relations between malaria and mosquitoes; has since made tropical hygiene his life study and has conducted investigations of the highest importance in many parts of the world. He received the Nobel prize for his work in medicine in 1902. ”

“ To the ordinary student of Tropical Medicine, who reads Protozoology, not so much with the hope of acquiring special knowledge as with the intention of keeping au courant with advances made in a science that so nearly touches his own subject, there is no more striking fact than the repeated and authoritative citation of the name and work of Schaudinn. ”

“ The causes of the ardent continued fever of the tropics, which is usually recognized as a form of simple continued fever, do not differ materially, except in degree, from those of the simpler forms of the disease; but exposure to the direct rays of the sun would seem to be especially prone to give rise to the disease in those who are unaccustomed to the heat of a tropical climate. ”

“ In a science which moved so fast as tropical medicine it was wholesome to have a periodical stocktaking of our knowledge on any given subject, and when one advanced a theory which ran contrary to generally-accepted ideas the review was all the more likely to be of a vigorous and radical character. ”

“ It ought to be well understood, that as we approximate tropical climates, the doses of medicine, when taken, should be increased in quantity, and repeated with less delay than is admissible in colder countries. ”

“ He showed, as you all know, that two species of amoebae are parasitic in the human colon, which, though similar in appearance, differ widely in their life-cycles, in their reproduction, and in their pathogenicity. The research was productive of results which are now among the most familiar facts in tropical medicine, and it is unnecessary to say more than that, while carrying it out, Schaudinn did not hesitate to repeatedly infect himself by swallowing the developmental cysts both of Entamoeba coli and of Entamoeba histolytica, and that he had, in consequence, two serious attacks of dysentery. ”

“ It is evident from what has been advanced that the student of medicine must be a naturalist before he can hope to become a scientific epidemiologist, or pathologist, or a capable practitioner. The necessity for this in all departments of medicine is yearly becoming more apparent, but especially so in that section of medicine which relates to tropical disease. ”

“ With his mind still hankering after tropical work, Schaudinn, soon after his report on Treponema pallidum had appeared, asked for six months' leave to study at the Hamburg School of Tropical Medicine, and to complete his arrangements for joining Professor Koch in an investigation of trypanosomiasis in East Africa. ”

“ An important one is to bring together the men who are interesting themselves in tropical medicine, with the idea that by so doing the subject itself will be advanced and we ourselves benefited. With a view to securing these objects, the Society has been placed on a basis as broad as possible. Although domiciled in the Metropolis, it is open to any member of the profession, whether domiciled in London, Great Britain and Ireland, or abroad, and also to those followers of any science or profession capable of forwarding, directly or indirectly, the interests of tropical medicine. ”

“ Nowadays quite a different feeling obtains in official circles, and instead of being repressed and cold-shouldered the investigator in tropical pathology is encouraged in every possible way by the British Government and its officers. Other Governments, too, have ceased to be indifferent; some are actively sympathetic. ”

“ Not only has recent discovery widened our horizon, but many additional workers are now in the field, and hitherto untrodden departments of natural science having a bearing on tropical pathology have been opened by the tropical pathologist. The multiplication of workers is extraordinary, and doubtless is accounted for by the establishment of the several tropical schools in Great Britain and else-where; not least by the sympathy and active encouragement that research in tropical pathology has received at the hands of the British Government. ”

“ Lately the distribution of the disease has much extended : several cases have been seen by me in Ceylon and Southern India, in which countries the affection was believed to be non-existent. Cases have also been reported from Brazil and other parts of tropical America.
Clinical Signs.—In a well-marked case the skin of practically the whole body is covered with round patches, each of which presents several concentric scaly rings. The scales are flaky, resembling tissue-paper, dry, of a dirty greyish colour, and slightly curled. ”

“ Of the 1000 pages in Allbutt's book, the first 200 are exclusively devoted to protozoa, mosquitoes, blood-sucking flies, and ticks. In Davidson's work there is hardly a sentence on these subjects. Practically, this is a new and a big and rapidly growing branch of tropical medicine.
In Davidson's work the first chapter in the section on General Diseases relates to malaria. It is a very complete, carefully-written article, embracing all the most important knowledge and views of the time; yet in that article there is not a single word on the mosquito as a carrier of malaria. ”

“ Then the tropical pathologist must take cognisance of a number of diseases of the lower animals, important in themselves, but more important in their bearing as illustrating principles applicable to human pathology especially tropical pathology. ”

“ The study of the arthropod blood-suckers and the correlated diseases has grown to be so vast a subject that for its proper appreciation special studies have to be made and its teaching relegated to special men. In Davidson's day a single culex was all that we had to bother ourselves about; but nowadays we have to know something about some 600 species of mosquitoes; and so in a less degree with ticks, tsetse flies, and several other though less important blood-suckers. Truly the burden of the student of tropical medicine has become a heavy one. ”

“ And not only in this matter of the malaria parasite, but in other and similar organisms. They have had no opportunity of seeing these things, in their Hying visits to this country, or of learning how to recognise them. They go abroad, and, although anxious to work, they are not in a position to work in a fruitful way. The tropical schools do much, but they do not adequately supply the wants of the flying visitor. I take it that our Society has a distinct role in this direction. ”

“ The students in the laboratory are given opportunities of making for themselves a collection of microscopical specimens of most of the common tropical diseases. They are instructed in the examination of meat at the Hamburg slaughter-house. Advanced students are welcomed for research work in the Institute. ”

“ I then venture with all humility to suggest that research should take this direction, and that during the attacks of elephantoid fever an attempt should be made to examine the serum and to cultivate it, and I shall look forward to the time when some skilled observer demonstrates the presence of some specific organism. ”

“ We now know that the sleeping sickness is a terminal phase of a trypanosome infection—a type of disease hitherto unrecognised in human pathology—that the immediate cause of the sleeping symptom is an infiltration of the lymphatic spaces of the brain with certain small mononuclear cells, that the disease is conveyed by the tsetse fly, and that it is amenable to some extent to arsenic, mercury, and certain dyes—all absolutely recent discovery. ”

“ 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. ”

“ And in the Tropics, where all forms of microbic life flourish so luxuriantly, where people go about bare-footed and bare-legged, where abrasions and injuries of exposed parts are of daily occurrence, where there is a frequent lack of cleanliness, surely there is ample opportunity for the entrance of pathogenic organisms and resulting attacks of lymphangitis, thickening of the lymph channels, and eventual obstruction. Would a peripheral lymphangitis of the scrotum not account sufficiently for a localized symmetrical elephantiasis with healthy skin uniting it to the body? ”

“ Climate may be an important factor. Thus liver diseases are far more to be dreaded in a damp tropical or semi-tropical region, and rheumatism and catarrhal affections in winter and in cold northern localities. ”

“ During this time they are taught the hygiene of vessels, including food and water examination, care of the sick on board, the duties of a ship doctor, such as the prevention and stamping out of infectious diseases, quarantine and disinfection, and practical information about malaria, sleeping sickness, kala-azar, yellow fever, scurvy, beri-beri, Malta fever, plague, cholera, typhoid, dysentery, and helminthology. ”

“ This serves for the breeding and development of mosquitoes, flies, ticks, snakes, etc. The ticks I saw were kept between two layers of tripod tables, enclosed in glass jars, with lids of wire gauze weighted with lead, and enclosed in tins of double saucers, containing petroleum or vaseline.
A museum of tropical hygiene is in course of arrangement, but all that was shown to us was a model of a mosquito-protected bed. There is a club-room for students, but there are no residential chambers for them in the building. ”

“ Much of this research is directed at the diseases of industrialized countries, as their treatment accounts for a substantial part of the sales of pharmaceutical companies. More research is urgently needed on the environmentally related tropical diseases that are the major health problem in the Third World. ”

“ The laboratory, built in 1906, is 58 ft. long by 19 ft. wide, with six large windows, and is fitted with gas, water, and electric light for twenty-four students.
The museum is arranged round the sides of the laboratory, and a good epidiascope exists. On the same floor there is a chemical laboratory of two rooms, another room for experimental operations on animals, without legal restrictions, and some smaller laboratories. On the second floor is the protozoology laboratory consisting of three rooms for five workers, a tropical room kept at a temperature varying between 77 deg. and 86 deg. ”

“ Heat and moisture, he contended, are not, in themselves, the direct cause of any important tropical disease. The direct causes of ninety-nine per cent, of these diseases are germs, and to kill the germs is simply a matter of knowledge and the application of that knowledge—that is to say, sanitary science and sanitation. ”

“ A predisposition to certain diseases, and a tendency to degenerative changes, may be brought about in this way; but acute disease, with active tissue change, is not so caused. In the tropics, as in temperate climates, in the European and in the native alike, nearly all disease is of specific origin. It is in their specific causes that the difference between the diseases of temperate climates and those of tropical climates principally lies.
Modern science has clearly shown that nearly all diseases, directly or indirectly, are caused by germs. ”

“ Within the tropics lengthened residence is the most essential qualification in a medical [134] attendant, as although old men may not be so well up to the latest improvements of the science as those fresh from college, yet they have from practice found out the best way of treating tropical diseases, to which the treatment applicable in a London, Edinburgh, or Paris hospital in similar cases, would be quite out of place when practised in so different a climate as the tropics, where the symptoms vary and succeed each other with ten times the rapidity they do in Europe. ”

“ So died Schaudinn, one of the greatest, if not the greatest, observer in natural science of all time. It is certain that his life was lost as a direct result of his disastrous experiment of self-infection, and it is more than probable that his health was undermined by his almost reckless industry. We are told that he would sit continuously for many days and nights, following at once the life-cycles of a series of different organisms, and that, like the chess-player who simultaneously engages five or six adversaries, he never forgot or confused the issues. ”

“ I think I have shown how very difficult it is to understand how such a complete obstruction as is required can take place.
Then we must remember that in a population which is infected to a greater or less degree by F. nocturna, any disease, whether it be pneumonia or Bright's disease, or eczema or elephantiasis, ought to show an amount of filarial infection equivalent to the general infection of the population. ”