Popular Science Monthly/Volume 76/April 1910/The Leading School of Tropical Medicine
|THE LEADING SCHOOL OF TROPICAL MEDICINE|
NO plan for improving American medical education has been more widely advocated the past year than the establishment of a department of tropical medicine in our medical schools. Although we now have such possessions in the tropics as Porto Rico, the Canal Zone, the Philippines, the Hawaiian and other islands of the Pacific, not to mention our semi-tropical southern states, instruction in tropical diseases and conditions has not kept pace with the increased need. The founding of a school of tropical medicine in the United States was first suggested by the Boston Medical and Surgical Journal in the same year that two schools of tropical medicine were planned for England. Since England was the first to establish such a school, let us look toward that country.
Up from the Jewish quarter of the city, on the crest of Brownlow Hill, stands Liverpool University, famous, as some one has said, for its zoologist, its physiologist and its professor of tropical medicine. Entering beneath the tall Victoria Jubilee Tower with its clock and Latin inscription, and crossing the yard, one comes to the row of buildings containing the Thompson-Yates and Johnston laboratories, the former and present homes of the Liverpool School of Tropical Medicine. It was the work of this institution which caused a New York physician, when describing the advantages a medical student can get abroad, to write, "Liverpool leads in tropical medicine."
Although the school was founded a few months after the plans for its rival in London had been published, it was, nevertheless, the first to begin work. Its opening days were not darkened by any unfortunate incident, yet they were clouded by the lack of those favorable circumstances which have made the London school what it is to-day. The institution at Liverpool was not founded by the government, it had no grant nor assured income, nor even government recognition, hence it could not expect to get as many students as its rival. Some of these obstacles were removed later, yet they were important in determining the lines along which the school must work. A school which could not hope for much through excellence in teaching must look for recognition through research.The necessity for conducting successful research was met by the appointment of Major Ronald Ross as professor of tropical medicine. The researches of Major Ross prior to his appointment at Liverpool
had disclosed the life history of the malarial parasite in the mosquito. That the mosquito was in some way connected with malaria was known as early as the fifth century, b.c., when Empedocles, a Greek philosopher of that period, delivered the people of Selinus, Sicily, from a pestilence by draining the neighboring marshes. Yet it was not until 1878, when Sir Patrick Manson observed the presence of the little worm, filaria, in a mosquito that there were any experiments to prove that mosquitoes carry disease.
In 1895, Major Boss, inspired by Manson, began to study the fate of the flagellating bodies which were first observed by the French army-surgeon, Laveran, at Constantine, Algeria. A few years later, being so situated as to be unable to continue his work on human malaria, Ross took up the same line of work in the malaria of birds. In July, 1898, he followed the development of the malarial organism from the pigmented cells found in the stomach of the mosquito to the rod-shaped bodies in the salivary glands. He then exposed birds free from parasites to the bites of such infected mosquitoes, and fourteen days later these birds had parasites in their blood. In this manner were demonstrated the development of the malarial parasites in the mosquito, the mode by which they were transmitted and the fact that not every kind of mosquito will transmit the microscopic animal which causes the disease. Although it was in birds that the complete life-cycle of the organism was first followed, the pigmented cells which were a clue to the discovery were first seen in man.
A few months after his appointment at Liverpool, Professor Ross left England for Sierra Leone, Africa, on the first of those expeditions which have made the school famous. The purpose of the expedition was to study still further the subject of malaria, but this time in the human being. Mr. Austen, of the British Museum, accompanied him for the purpose of collecting and studying the various kinds of mosquitoes and noxious insects.
This first malarial expedition was followed by many other such expeditions; and the value of the four measures for the prevention of malaria advocated by Professor Ross may be seen in the results that followed the expedition to Ismailia in 1902. Ismailia is a town of under 6,000 inhabitants, situated close to the Suez Canal and controlled by the Suez Canal Company. The number of cases there rose from 300 in 1877 to 2,250 in 1900. An active campaign of first detecting, isolating and treating the sick; second, segregating the healthy; third, mechanically protecting the well from mosquitoes; and fourth, reducing the number of mosquitoes by drainage or other treatment of their breeding places, begun in 1902, reduced the number of cases from 1548 to 37 in 1905; and all the old cases of 1905 were cases of relapse.
In 1902, Professor Ross received a Nobel prize for his researches on malaria. In 1906, he went on a malaria expedition to Lake Copais, Greece, and in 1907, he was sent at the request of the Government of Mauritius to give advice on the prevention of malaria in that island of the Indian Ocean. It will thus be seen that the work of Professor Ross is not only of scientific value, but thoroughly practical as well.
Another malady closely associated with malaria is blackwater fever. The classical description of this disease has been written by another teacher of this school, Dr. Stephens, who, next to Professor Ross, has done so much to spread a knowledge of malaria and tropical medicine. In 1907, Dr. Nierenstein, a chemist of the school, discovered certain etiological factors in this malady; and in July of the same year, the nineteenth expedition was sent to Africa to study blackwater fever.A second disease conveyed by mosquitoes is yellow fever, which is distinctly American in origin. Found by Cortez in Mexico and
unknown in Europe until after the discovery of America, it has been epidemic many times in the United States, in places ranging from Pensacola to Boston. An excellent account of the last epidemic, which occurred in New Orleans, in 1905, has been written by Sir Hubert Boyce, the Dean of the Liverpool School.
Three expeditions have been sent from Liverpool to study yellow fever, and all the members of both expeditions to Brazil were stricken with the disease. Dr. Walter Meyer, a member of the first expedition, and a young man of great promise, died of the fever. One of the members of the second expedition had a severe attack of the disease, followed by disagreeable and disfiguring complications. His misfortunes did not end Here; for, during convalescence, the river boat on which he was being carried sank and he barely escaped with his life, only to meet still further disasters in another land. Dr. Thomas, the other member of this expedition, has succeeded in conveying the disease to the chimpanzee by the bites of infected mosquitoes, thus affording a lower animal to take the place of the human sacrifices made to discover the cause, and also offering a hope for a cure.
A third disease spread by mosquitoes is filariasis, a worm infection of the lymphatics and of the blood. The work of the school in this direction has been to describe a number of new species of filaria found in birds. This work is said to be in large part due to the observations of the late Dr. J. Everett Dutton, who so soon afterward made such important discoveries concerning two diseases of Central Africa.
The first of these African diseases, sleeping sickness, is spread by one of the biting tsetse flies. The cause of the infection, which had escaped detection during a century of its existence known to Europeans, was at last seen by Dr. Forde, in 1901. It was Dutton, however, who first recognized that the little flagellate in the blood of Dr. Forde's patient was a trypanosome, similar to those which cause disease in lower animals. Dutton was the first to give full details regarding the character of the organism, to describe the symptoms produced by it and to give it the name it still holds.
The Liverpool school has sent four expeditions to study sleeping sickness. The experimental work which was carried on in England was begun in 1903 with material brought back from the Gambia by Dutton. At first the researches were conducted in Liverpool, but as the work expanded and the material increased, it became necessary to find a place in the country where the work could be more fittingly carried on. Such a place was found at Crofton Lodge and Cottages in Runcorn, a town sixteen miles from Liverpool. There, in a roomy rambling old country house beside a sunken road, with two tall holly trees guarding the entrance, might be found at one time research workers from India, Russia, Austria, Canada and the United States, who kept at their work from early morning until nearly midnight, and occasionally all night.
The most important experimental work of the laboratories in Liverpool and in Runcorn has been the search for a cure for sleeping sickness. These investigations were begun by Dr. Thomas, who was the first to use and recommend atoxyl, the remedy which Koch used later in Africa with so much temporary success. Although the little animal disappears from the blood and the fever subsides after the use
of atoxyl, there is later likely to be a recrudescence; and it was for this reason that two chemists at Liverpool, Professor Benjamin Moore and Dr. Nierenstein, conducted still further research for a better remedy. These men found that although atoxyl killed most of the organisms, a resistant form was able to withstand the action of the drug. A second remedy was then given during this resistant stage, and success seemed assured. The disease may continue for many years, however, so it is too early to know how effective the double remedy is in man.
It is interesting to observe that as in malaria the complete lifecycle of the parasite was first followed in bird malaria; so in sleeping
sickness what is apparently the complete cycle has been worked out in trypanosome infection of the frog. It was observed by Dutton in the Congo that the frog trypanosome undergoes another cycle of development outside the frog; and the recent experiments of Kleine in German East Africa seem to point to another cycle of development of the trypanosome of man in the tsetse fly. Thus the study of infections in lower animals may be of the greatest assistance in solving the problems of disease in man.
The other of these two diseases of Central Africa is tick fever. This infection was first described by Dr. Livingstone, the famous explorer, who found the disease in Portuguese South Africa, and attributed it to the bite of a tick. The discovery that spirochætes could be found in the blood of every patient ill with tick fever was first published by P. H. Ross and Milne, though there has been some doubt whether their work antedated that of Dutton. However, Dutton was not only able to say that the cause of the fever was a spirochete, but was able to prove by experiment that the spirochete was conveyed to the healthy subject by the bite of a tick, the Ornithodoros moubata, and that the larvae hatched from eggs laid by an infected tick, could convey the infection at their first feed.
Dutton's work in the Congo, on tick fever, was interrupted by the illness of both members of the expedition. This occurred at the time that Ross and Milne published the results of their discovery in Uganda. In February, 1905, three months later, Dutton died in Africa.
Further experiments were carried on in the laboratories at Runcorn, where it was found that the spirochete of African tick fever was a new parasite, quite different from a similar organism which causes the relapsing fever of Europe. By common consent this new parasite was called Spirochceta duttoni, in honor of the hero who gave his life in an effort to relieve suffering humanity.
Such have been the results gained by the school in a study of five parasitic diseases conveyed by mosquitoes, flies and ticks. There are many other investigations of importance to the physician and scientist, but of less general interest. How valuable the work of the school may be in lines not strictly medical was recently demonstrated in the West Indies by Mr. Newstead, the entomologist of the twenty-first expedition.
This institution, great as it is, has been supported chiefly by annual subscriptions, as the school has no endowment. Foremost among those who have contributed most liberally is Sir Alfred Jones, who founded it. Another benefactor, who has shown his appreciation of the work done in the Congo, is the King of Belgium; and recently the English government has given its support. Much of the work has been planned and the interest in it aroused by the Dean, SirBoyce.
This school, in the short space of ten years, has accomplished more than many an older institution.