Tropical Diseases/Chapter 26
CHAPTER XXVI
EPIDEMIC DROPSY
Definition and description.— A specific, epidemic, perhaps communicable disease, running its course in from three to six weeks, and characterized by the sudden appearance of anasarca, preceded in most instances by fever, vomiting, diarrhœa, or by irritation of the skin, and often accompanied by a rash, by fever of a mild, remitting type, by disorder of the bowels, and by pronounced anæmia. The case-mortality varies from 2 to 40 per cent., death being sudden and depending upon œdema of the lungs, hydrothorax, hydropericardium, or other pulmonary and cardiac complications.
History and geographical distribution.—The foregoing is a concise description, drawn principally from McLeod's account (Trans. Epidem. Soc. Lond., N.S., vol. xii.) of a disease which appeared in Calcutta, it is believed for the first time, in the cold weather of 1877-78, of 1878-79, and 1879-80. On each occasion it disappeared with the advent of the hot weather. The same, or a similar, disease broke out at Shillong, Assam, 5,000 feet above the level of the sea, in October, 1878; at Dacca in January, 1879; at South Sylhet in the cold weather of 1878-79; and in Mauritius (Lovell and Davidson), having been imported from Calcutta, in November, 1878. There are no trustworthy accounts of its occurrence else- where, although certain vague statements seem to indicate that it appears at times in other parts of India. In Mauritius it prevailed until June, 1879, attacking about one-tenth part of the coolie population, of whom 729 died, a mortality of about 2 or 3 per cent. At Sylhet there were no deaths; at Shillong also the mortality was insignificant; but in Calcutta the death-rate in those attacked was estimated as high as 20 to 40 per cent. Coolies and natives were alone affected; Europeans enjoyed a complete immunity. In Calcutta the disease was confined to a particular quarter; here it attacked families and groups of people, slowly extending its area, but at no time becoming generally epidemic throughout the city. A very limited epidemic of the disease appeared in Calcutta in 1901, and again in 1908-9.
Etiology.— Both sexes were attacked; children under puberty were less liable than adults; sucklings were seldom affected. The weak and the robust were equally susceptible. There are no direct observations on the germ of the disease; there is indirect evidence of its portability and of its communicability. But as to whether it is directly communicable from man to man, or whether it, or its cause, is indirectly transmitted through some unrecognized medium, has not been determined. Evidence of its capacity for remaining latent for a considerable period is supplied by the history of the successive epidemics in Calcutta, where it is said more especially to affect the Hindus. The disease could not have been a very catching one, seeing that no medical man was attacked, and that, except in the case of Mauritius, it spread but slowly.
Major Greig, who has made a special study of the disease during the epidemics in Calcutta, concludes that epidemic dropsy resembles ship beriberi, and that it is conduced to by a " one-sided " dietary of cereals from which the vitamine elements have been removed by over-milling. He remarks that the rise and fall of several of the epidemics have synchronized with periods of high-priced grain, when the poorer classes could not afford to supplement, as they do in more normal times, the cereal diet with additional articles of food. The nature of the disease is still obscure; many believe it to be nothing but beriberi, and it is possible that observers, while entertaining opposite opinions, have been dealing with two different diseases.
Identification.— McLeod, after a careful analysis of all the available evidence, concludes that epidemic dropsy is a disease sui generis. At the time of its occurrence in Calcutta many of the physicians there looked upon it as a form of beriberi; and, indeed, in many respects it resembles very closely those cases of beriberi in which dropsy is a prominent symptom, and in which the nervous phenomena are slight or altogether absent. But in epidemics of beriberi such cases are the exception— in fact, are very rare, and always concur with others in which nerve symptoms are pronounced, and with purely atrophic cases; such were not seen in either the Calcutta or the Mauritius epidemics. In epidemic beriberi the mortality is much higher than in the Shillong and Sylhet epidemics. Furthermore, beriberi is a much more chronic disease, is not accompanied by an eruption, and but seldom with well-marked fever.
Special symptoms.— According to McLeod, dropsy was almost invariably present. It usually appeared first in the legs, and in some instances was confined to the lower extremities; in others it spread and involved the entire body. Occasionally it was very persistent, lasting and recurring during convalescence.
Fever also was a very constant symptom; sometimes it preceded, sometimes it accompanied, sometimes it succeeded the dropsy. It was rarely high, ranging usually from 99° to 102° F.; in a few cases —possibly from malarial complications— it reached 104°. Rigors were rare.
Diarrhœa and vomiting generally ushered in the disease in the Mauritius epidemic. In Calcutta these symptoms were not so frequent, although they were by no means rare there, occurring at both the earlier and later stages. Dysentery was common in the Calcutta epidemic.
Nervous symptoms— such as burning, pricking, itching, and feelings of distension of the skin, sometimes limited to the soles and feet— often preceded the dropsy. Distressing aching of muscles, bones, and joints, worst at night, was usual. Anæsthesia of skin areas and paresis of muscles were never observed in Mauritius. Harvey remarked two cases in Calcutta exhibiting doubtful paretic symptoms; these are the only two recorded in which there was anything resembling the paretic symptoms usually so prominent a feature in beriberi.
An exanthem, erythematous on the face, rubeolar on the trunk and limbs, was frequently seen in Mauritius, less frequently in Calcutta. It appeared about a week after the œdema, and lasted from ten to twelve days.
Circulation and respiration.— Disturbances of the heart and circulation were prominent features in nearly all the cases. The pulse was weak, often rapid and irregular; cardiac bruits were also noted. Breathlessness on exertion occurred in all cases; severe orthopnoea in many. Signs of pleural and pericardial effusion, of œdema of the lungs, of pneumonia, and of cardiac dilatation were common in Calcutta.
Anœmia was usually present and marked; so were wasting and prostration. Scorbutic symptoms occasionally showed themselves.
The liver, spleen, and kidneys were not specially affected. The urine was rarely albuminous.
Morbid anatomy.— Beyond general œdema and occasional pleural and pericardial effusion, nothing special was remarked post mortem.
Treatment.— In the absence of anything like precise knowledge of the cause and pathology of epidemic dropsy, treatment must be entirely symptomatic. Mild purgatives, the exhibition of digitalis when there is evidence of cardiac weakness, and the occasional use of the nitrites in the fits of orthopnœa might prove serviceable. During convalescence iron and arsenic are indicated.