Journal of a Seaplane Cruise Around The World
Monday, November 12
The School of Tropical Medicine in Calcutta is perhaps the leading institution of its kind in the world, and is the seat of tremendous activity . . . Tropical diseases are apt to be dull study to medical students in temperate zones, because they are only legendary, so when I entered the School it was in green ignorance, and I could only seize upon the most interesting points for momentary but earnest discussion with the specialists who were dug out of their laboratories by Col. Knowles, the acting director, to meet the American visitor. Malaria, Kala Azar, Leprosy, Epidemic Dropsy, and Drug Addiction each had a lesson to teach:
1. Malaria seems to have occupied most of Col. Knowles time, though he has entered many other fields. Being a protozoologist, he has followed particularly the carrier side of the disease. His office and the adjoining halls are filled with demonstrations of the development and transmission of the organism. I was most astonished however on learning how deeply Malaria has penetrated the country, and how relatively ineffective attempts at treatment have been. The question was reviewed by Knowles* in 1930:
2. Epidemic dropsy was a new one to me and it appeared out of a clear sky as we entered a suite of rooms and were surrounded by 6 or 8 Indian research workers who arose as Col. Knowles appeared. In a corner were two artists doing colored plates of skin diseases, and the drawing now reaching completion was of the legs and torso of a man afflicted with this disease. The legs were edematous and tense, but the rest of the body was free from hydrops. (Transudations are found sometimes in the pericardium and pleura, but ascites is rarely present). The curious feature, and the one which provoked the drawing, was a number of scattered "sarcoid" eruptions over the trunk. They were telangiectatic lumps, bright red, and sometimes raised so far as to become pedunculated. They disappear after the disease subsides, and are thought to be due directly to toxic action on the ondothelium; - for this is a capillary dropsy more than a lymphatic one. I suggested a neural origin for those lumps, but found no sympathy there. Some one appeared with a demonstration board of rice kernels; some normal, others slightly swollen and containing a dark vacuolated center. Cultures of these centers give a bacillus which when grown on rice media, produces toxins leading to dropsy -- so they believe to have proven the infectious origin of this dropsy, and contend that while related in a way to beriberi, it is quite distinct. The rice is at fault because of molding from dampness; proper preservation prevents the disease. There is an excellent review of this, as well as of the other activities of the School in Col. Knowles, An Essay Review of the Calcutta School of Tropical Medicine, 1920-33.
3. Leprosy has been studied so long and so thoroughly that there was some surprise when I asked to see the department chief - but I explained that it was to improve on my experience in Iceland. I do not know the man's name, but he was a good teacher, and we examined some 12-15 cases together. For the first time I began to appreciate its diagnosis: any skin eruption which is anaesthetic, or which has above it a thickened cutaneous nerve. Amazingly simple, and it worked out in every case shown. On the first one, I mistook the enlarged dorsal nerve for a tendon; only it ran around the radius at the wrist! Practically all lesions were dry, mostly just a thickening of the skin. Usually a single patch on chest, back, arm, hand, leg, or less rarely on the face or ear lobe; -- one which might have been the result of bromides, syphilis, or just plain filth -- but the cutaneous nerve was often to be found (or a scar, after the nerve had been cut out for diagnostic studies).
Diagnosis was made formerly only with demonstration of the bacillus in the skin, and treatment withheld unless it could be successfully shown; now this is no longer required, so that a great many more persons are receiving treatment. Only one case in ten (or more) reaches the advanced stage of textbook illustrations; and since relatively few persons are treated, the conclusion results that, like tuberculosis, the disease is frequently self-arrested. There are undoubtedly above 5,000,000 lepers in India!
4. Kala Azar (Leishmania donovani) is a paradox, because a successful treatment has been discovered before the epidemiology of the disease has been satisfactorily worked out. It came perhaps from China, settling in the Madras district prior to British occupancy. It has moved steadily northward, in epidemic migrations, and from the description which Dr. R.A.O. Smith gave me of these new epidemic centers, one would suppose that the previous homes of the disease were so well accustomed to it that the damage done was unimportant; only in new fields is it a torrent of sickness and death. The latest fields of invasion have been Assam and the Brahmaputra valley. The intravenous use of antimony (tartar emetic), which was started by Caronia and Di Cristina in Italy, in 1915, was adopted immediately by India, and in 1921 an even better pentavalent antimony was brought out. "The result of these measures has been, not merely to hold the disease in check, but to eliminate it". Kala Azar is on the wane, proof that the chief reservoir of the Idishmania is in the human and not in animals; but in Bengal unfortunately dermal leishmaniasis has increased, while the systemic disease has declined, so that there is still a reservoir present in the human from which sandflies may secure and disseminate the organism. Diagnosis of the disease after it is once suspected, which rested formerly on the examination of thin blood films for L. donovani, is now done by Chopra's antimony test (1927), a coagulation phenomenon which can be made successfully with finger print blood. Treatment: Untreated Kala Azar has a mortality rate of from 70% to "cent-per-cent"! Antimony tartrates are cheap and reduce the mortality to 14-25%, but they are not harmless and the course is long. Several pentavalent antimony compounds have been used in the past 15 years, and the standard treatment is now 0.3 to 0.5 grams of neostibosan (Bayer) for 8 daily doses, a total of 3.7 grams. The spleen puncture may still show parasites at the end of this treatment, but the patient recovers if left alone. The cure is accompanied by a complete change in the ratio of serum proteins, which become normal again only after 120 days, simultaneously with the appearance of a negative aldehyde test. Of 102 patients treated in 1931 with this method, 95% were cured, 3% died. (In the press last winter appeared notices of "fouadin", a trivalent antimony preparation -- this is used chiefly for dermal leishmaniasis.)
The question of transmission of Kala Azar is now at the forefront, but progress is being made slowly. True, the sandfly Phlebotomus argentipes is the guilty carrier by every rule of epidemiological practice: endemic Kala is transmitted by a biting insect of very limited range of flight; the disease corresponds to the areas in which the sandfly P. argentipes is most apt to live; and this very insect (one of four varieties of phlebotomus in India) after being fed on blood of Kala Azar patients, shows typical herpetom forms of L. donovani in the foregut or midgut within 3 to 5 days after the infective feed. This definitely involves the sandfly (1924 ) as the next step of the development - but, and it is a big word, never has a human being been given kala azar by the bite of an experimentally infected sandfly! Is this due to absence of secondary factors such as debilitation, fatigue, famine, or low vitamins intake? Dr. Smith is an entomologist, and has been breeding sandflies for 10 years, meanwhile giving great attention to the problem of finding another animal besides man which will develop kala azar. The monkey has contributed something, because he is more susceptible to Leishmaina d. if he is already sick with monkey malaria (Plasmodium knowlensi). As a laboratory breeding ground all sorts of small animals have been tried but only the Chinese hamster (a small field mouse) is easily infected by injections of the organism, and slightly less easily by feeding the germs. It becomes important to determine if the infected sandfly can bite the disease into a hamster, and I was shown the little mice living "peacefully" in individual cages (if two are put together, only one survives the playful ferocity of the other); and the men lying on the floor of the room holding caged sandflies over their faces to feed upon their infected blood, and was told that natural infection of hamsters has actually been accomplished --- but in discouragingly small numbers. Fed repeatedly over months, then watched for a year and a quarter, 2 out of 28 developed Leishmaniasis. It looks like a downwind land in the Piaxtla Canyon to me!
5. Drug addiction: Opium (smoking chiefly, not used in pure alkaloidal form) is only moderately widespread; practically all being smuggled in, for the growth of the poppy is well controlled. The rise of opium consumption (and it has risen) runs almost parallel with the increase in the Sikh population --- the Sikhs are the bearded fellows who run all the taxicabs in Calcutta. Infants are doped frequently (to keep them quiet), and the adults use it for euphoric and aphrodisiac effects. Cocaine - introduced only 40 years ago (as an aphrodisiac) is a growing danger. Usually eaten with betel leaf and pan. No mfr. in India, but smuggling trade estimated at 200,000 ounces yearly. Chloral hydrate a curious affair, - used to make bad likker better, narcosis being the standard by which drunkeness is judged. It's effects are worse, both to psychology and organic health, than those of any other drug.
Before leaving the School, I should mention (1) the work of the artists, whose collection of 1200 color plates of skin affections is crying for reproduction. (2) the new Rockefeller unit, The All-India Institute of Hygiene and Public Health, which stands, ant-proof, across the street. It is under the direction of Col. Baptist, -- with its spacious laboratories, it looks empty in contrast with the School, where every hall corner is filled with microscopes, demonstrations, etc. But it has only broken ground really, and was finished within the year. Two departments are running, two more planned, but they work together admirably, and many of the names famous in the School are actually to be found on the doors across the street -- Leprosy and Kala Azar are both centered here.
The visit to The Asiatic Society was all too brief. The Dutch Secretary, Dr, Van Manen, is much like Klebs, and given to interrupting his and other's work to discourse in fascinating matter on texts of philosophy. His favorite subject is Tibet, his servants are Tibetans, and he speaks and reads the language. We had hoped to secure information about a tribe of sea gypsies called Mawkens, but he was unfamiliar with the group, and he recommended instead the Andamons (but not for us - they shoot too accurately!). .
Walford came to dinner and proved to be most pleasant company. Likes India, the Indians, and his holidays near Madras. We are retiring early, and have arranged for 4:30 rising.