DENGUE.
BY H. D. SCHMIDT, M.D.
SYNONYMS.—Break-bone fever, Dandy fever.
HISTORY.—The history of this disease dates only from the second half of the last century, though it appears very probable that previous to this time dengue existed in the tropical regions of Africa and Asia, whence it was carried to Europe and America.
In Spain the disease has been known since 1764, when, up to 1768, it prevailed in Cadiz and Seville under the name of la piadosa or la pantomina.1 In 1780 it appeared in the form of an epidemic in Philadelphia, where it was first noticed and described by Rush under the name of bilious remitting fever, commonly called break-bone fever on account of the violent pains attending it. Next it prevailed in Calcutta in 1824, and two years afterward it made its first appearance on the southern coast of the United States, in Charleston and Savannah, where it prevailed to 1827. Toward the close of 1827 another dengue epidemic broke out in the West Indies, whence the disease proceeded to the American continent, reaching New Orleans in the spring, and visiting Charleston and Savannah in the summer and autumn of 1828.2 In 1844 it showed itself in Mobile, and in 1848 in Natchez, whilst in 1850 it reappeared along the Southern seacoast, particularly in Charleston, from which it proceeded even to inland towns, such as Augusta, Ga.3 In 1865 dengue appeared in Teneriffe and other Canary Islands, whilst at the same time and through the years 1866 and 1867 it prevailed in Andalusia and in some other Spanish provinces.4
1 R. H. Poggio, La calentura roja observada in sus apariciones epidemicas de los anos 1865 y 1867, Madrid (reported in Virchow und Hirsch's Jahresbericht für das Jahr 1871, vol. ii. p. 200).
2 G. B. Wood, Practice of Medicine, 4th ed., vol. i. p. 444.
3 S. H. Dickson, Elements of Medicine, 2d. ed., p. 747.
4 R. H. Poggio, Virchow und Hirsch's Jahresbericht für das Jahr 1871, vol. ii. p. 200.
One of the most extensive epidemics of dengue prevailed from July, 1870, to January, 1871, in Zanzibar,5 on the East Coast of Africa, whence it extended to Aden in Arabia and Port Said in Egypt. In December, 1871, the disease appeared simultaneously at Bombay and Calcutta,6 to which place it had been carried by transport-ships from Aden. Proceeding from Bombay in a northern direction along the railroad, it spread over the central regions of the North-western Provinces, the Rajputana states, Cashmir, and the Punjaub. From Calcutta it passed over Assam and Bhotan to Thibet, and thence downward into Burmah and to all the large cities along the coast; while it also extended along the coast of Malabar over Visigapatam to Madras and Pondichery, finally arriving at Mysore. Thus the disease had actually spread over the whole Peninsula from Cape Tutikorin to the foot of the Himalayas, attacking equally all races or nationalities without regard to age, occupation, or position. Forty years previously, however, an epidemic of dengue had prevailed in Burmah. In 1873 it appeared on the island of Mauritius, to which it had been carried from India by an emigrant ship. In the same year a considerable number of cases of dengue were observed in New Orleans. In 1877 it appeared again in Egypt, where it prevailed in Ismailia.
5 J. Christie, "Remarks on Kidniga Pepo, a peculiar form of exanthematous disease epidemic in Zanzibar, East Coast of Africa, from July, 1870, to January, 1871," Brit. Med. Journal, July 1, 1872, p. 577 (reported in Virchow und Hirsch's Jahresbericht für das Jahr 1872, vol. ii. p. 203).
6 Virchow und Hirsch's Jahresbericht für das Jahr 1873, vol. ii. p. 208.
Finally, in 1880, dengue, in the form of a very extensive epidemic, prevailed once more along the Southern coast, visiting equally Charleston, Savannah, and New Orleans. A number of valuable observations concerning the nature and symptoms of the disease were made during this epidemic by Drs. D. C. Holliday of New Orleans, J. G. Thomas of Savannah, and F. T. Porcher and J. Forrest of Charleston.7 At the same time it prevailed at Alexandria8 (Egypt) to such an extent as to affect nearly the whole population.
7 The papers of Drs. Holliday, Thomas, and Porcher were read before the American Public Health Association at its annual meeting, December, 1880, and published in the Proceedings of the Association. Dr. Forrest's paper was published in the American Journal of Med. Science, April, 1881.
8 A. Vernoni, "Le Dengue à Alexandrie d'Égypte en 1880," Gaz. hebd. de méd. et de chir., 41, 42 (reported in Virchow und Hirsch's Jahresbericht für das Jahr 1880, vol. ii. p. 5).
Dengue has been known under various popular names which it received from the people of the particular localities where it appeared in epidemic form. Even the designation, dengue, itself, by which the disease is at present generally known to the medical profession of the leading civilized nations, is of popular origin,9 for it is supposed to be a Spanish corruption of the word dandy, the name of dandy-fever having been jocosely conferred on the disease by the negroes of St. Thomas from the stiff carriage of those affected with it. At Zanzibar it received the popular name of kidniga pepo, signifying spasmodic pains.
9 G. B. Wood, Practice of Medicine, 4th edit., vol. i. p. 444.
DEFINITION.—Dengue is a peculiar febrile disease, generally appearing epidemically in tropical or semi-tropical regions, and characterized by a single paroxysm with or without remissions, severe pains, and stiffness in the joints and muscles, a peculiar exanthematous eruption, and almost never terminating fatally.
SYMPTOMS, COURSE, AND DURATION.10—Dengue never commences with a decided chill, though in many cases the attack of the disease is preceded by a feeling of general uneasiness and depression, vertigo, and headache, or even by a slight chilliness—a condition which may last from a few to twelve or even eighteen hours. In the majority of cases, however, the disease appears suddenly, very frequently at night, and announces itself at once by pains and a feeling of stiffness in the muscles, joints, back, and loins; in severe cases the pain may even extend to the bones.11 The larger and smaller joints are equally affected, either simultaneously or successively, and frequently swollen, those of the hands and feet generally before the others. The pain in the joints is increased by motion, and is therefore justly regarded by most authors as rheumatic in nature. The same may be said of the muscles. Sheriff even observed redness of the skin covering the joints. According to the degree of severity of the case these pains may be more or less intense. In some cases hyperæsthesia of the skin of the palms of the hands and of the soles of the feet has been observed.
10 Judging from the various accounts rendered by a considerable number of observers, it appears that the clinical symptoms of dengue had been the same in all the different localities on the globe where it has hitherto prevailed epidemically.
11 M. Sheriff, "History of the Epidemic of Dengue in Madras in 1872," Med. Times and Gazette, Nov. 15, p. 543 (reported in Virchow und Hirsch's Jahresbericht für das Jahr 1873).
Simultaneously with the affection of the joints and muscles the fever commences; its duration is from four to five days on the average, with one or, in exceptional cases, even more remissions. The temperature of the body during the first and second days of the fever rises to 102, 103, or even to 105° F; it then declines, to return to the normal standard on the fifth day. According to the measurements made by the late Dr. D'Aquin12 of New Orleans, the temperature curves of dengue showed a continuous and steady rise until the highest point was reached on the first, second, or third day of the attack; then comes a short stadium of a few hours, and then a remission, soon to be followed by another rise of temperature, which, however, never reaches the maximum point of the first. The pulse rises with the temperature of the body, generally to from 80 to 120 beats a minute, and subsequently declines with the temperature. Delirium is very rarely observed in adults, but frequently in children, though without aggravation of the other symptoms. The face is generally flushed, the eyelids swollen, and the eyes injected and watery. The tongue in the beginning of the disease is covered with a white fur; its edges are red and its body swollen. As the disease advances the coating increases in thickness and assumes a dirty yellow color. The appetite is lost, without excessive thirst. In many cases there is slight irritability of the stomach, accompanied sometimes with nausea, though vomiting rarely takes place. The condition of the bowels is variable. The urine is small in quantity, and highly colored in some cases, whilst in others it has been reported to be pale and copious, and rich in phosphates in the beginning of the disease; it seldom shows any sediments and very rarely contains albumen. The disease generally reaches its acme on the third or fourth day, when the fever commences to subside, and an amelioration of the other symptoms takes place, so that the patient feels greatly relieved. This, however, is only of short duration, for not many hours afterward the fever rises again, while the other symptoms also increase in severity. At this time an exanthematous eruption appears upon the upper part of the body, the face, neck, breast, and shoulders, which in the course of two days extends over the whole body. Simultaneously with the appearance of the eruption the lymphatic glands of the back of the head and those of the neck, axillæ, and groins commence to swell; in severe cases the mucous membranes of the nose, mouth, and pharynx also become congested. The eruption, which is attended with much heat, itching, or even pain, is not uniform in character; for while in some cases it may represent a simple rash or erythema, it resembles in others the eruptions of scarlatina, rubeola, lichen, or urticaria. Frequently it is very light and evanescent, showing itself only for a few hours, and perhaps in the majority of cases it does not appear at all. In the severer cases it generally remains two days, when it commences to fade and disappear with desquamation, while at the same time the fever subsides and disappears entirely, though the stiffness and soreness in the joints and muscles, together with the inflammatory condition of the superficial lymphatic glands, may persist for many weeks. In exceptional cases the eruption, after an intermission of a few days, reappears, generally with greater intensity and with an aggravation of the other symptoms. In others, again, it has been observed to remain a whole week.
12 D. C. Holliday, "Dengue or Dandy Fever," read before the Amer. Publ. Health Assoc. at New Orleans, December, 1880.
Hemorrhages from the nose and gums are also occasionally observed. Holliday even observed the occurrence of black vomit in the cases of two female children, aged respectively six and twelve, in the same family, who had suffered from yellow fever in 1878; they both recovered from the attack of dengue, though they were extremely ill and much prostrated. In female patients an attack of dengue not unfrequently causes the reappearance of the menstrual flow, while the pains attending the disease equally predispose to premature labor in pregnant women.
In severe cases of dengue the prostration following upon the subsidence of the fever is very great, for the patient is affected with a general weakness both of body and mind, indicating a great loss of nervous energy. In some cases observed by Slaughter the memory for names and words, as well as the ability for correctly writing even short sentences, was lost for one or two weeks after the commencement of convalescence. In children also cases are reported in which the mind remained affected for a short time after the attack. The convalescence in dengue, therefore, is comparatively slow, particularly as the pains in the muscles and joints, as already mentioned, pass away only gradually.
The duration of the disease, including the stage of convalescence, of course depends upon the degree of intensity of the attack, and accordingly varies in different cases. In a great number of cases dengue manifests itself only in its milder form. The average duration of the disease is from three to six days.
PATHOLOGY.—The pathological changes taking place in the different organs during the course of dengue are unknown, on account of the almost constantly favorable termination of the disease. From the peculiar features of some of the clinical symptoms accompanying the disease, however, we may speculate to a certain extent upon the nature of the pathological processes to which they are due. The sudden appearance of the characteristic pains in the muscles and joints, but particularly those in the head, neck, and loins, accompanied by a comparatively high fever, evidently point to the presence of an infectious poison in the system, though the question whether the noxious influence of this poison primarily affects the blood or the nervous system will be difficult to answer. But, judging from the early appearance of the pains, as well as from the physical and mental depression of the patient, we may presume that the nervous system is involved from the very beginning of the disease, and that the pains depend upon a hyperæmic condition of the affected parts, probably caused by a vaso-motor paralysis. The great resemblance of the painful affection of the muscles and joints in dengue to that of acute articular rheumatism leads to the supposition that the pathological condition in these joints is the same in both diseases; this view appears to be held by the majority of medical observers. In dengue, as in rheumatism, the pain due to the pressure of the hyperæmic and swollen tissues upon the irritated sensory nervous filaments is increased by motion—a phenomenon generally absent in neuralgia. The persistent headache, restlessness, and want of sleep, as well as the delirium and loss of memory observed in the severer cases, furthermore indicate a hyperæmic condition not only of the pia mater, but even of the brain-substance.
It is to be regretted that the literature of dengue within our reach shows no record of a quantitative analysis of the urine, from which we might have learned the quantity of urea secreted during the different stages of the disease, and which might have enabled us to form some idea of the extent of the destruction of the albuminous substances during the febrile stage, though, judging from the high grade of fever observed in the severer cases, we may well presume that the interchanges of matter are considerably augmented during this stage; while, on the other hand, the great nervous prostration of the patient directly after the subsidence of the fever, as well as the tardy convalescence, sufficiently shows that a large part of this waste is derived from the nervous tissues. The exanthematous eruption, representing a hyperæmia, or even an inflammation, of the skin, furthermore contributes to depress the nervous system by the pain and itching which it causes. This eruption, together with the inflammation and swelling of the superficial lymphatic glands, we are inclined to associate with the final elimination of the infectious poison from the organism.
Very little also is definitely known about the condition of the remaining organs, such as the kidneys, liver, and alimentary canal. The examinations of the urine in dengue recorded in literature are very few in number, and appear too unreliable for drawing any definite conclusions from them with regard to the condition of the kidneys. As albuminuria is met with in other infectious diseases, it is not impossible that it has also occurred in severe cases of dengue; though from the favorable termination of the disease it appears quite improbable that organic changes take place in these organs. In the same way may the liver be functionally deranged, or, judging from the destruction of matter during the febrile stage, a slight fatty infiltration of the organ may even occur—conditions which are apt to pass away with the exciting cause. The gastric irritability, whenever present, may be of nervous origin, though the vomiting, and particularly that of black hemorrhagic matters, observed in exceptional cases, evidently depends upon a hyperæmia of the stomach.
ETIOLOGY.—There is nothing positively known of the origin of dengue, but in perusing the accounts given by a number of medical observers from the different localities of the globe where it prevailed, we may presume that it existed in some parts of Asia and Africa long before it appeared in Europe and America. Perhaps the earliest record of dengue is the one dating from Cadiz and Seville, and concerning the epidemics prevailing in the cities in 1764 and 1768, when it was believed by the people that the disease had been imported from Africa. In Zanzibar (Christie), during the epidemic of 1870, the older native inhabitants remembered that fifty years before the disease had prevailed in this place. The Arabians living at this island also had known the disease in their own country, while the inhabitants hailing from the East Indies had never seen it. From the accounts of other writers we may presume that dengue has been known in Arabia for many generations. But, leaving aside its origin, it is authentically known that wherever dengue has appeared it has almost always been in the form of an epidemic, spreading from place to place and from family to family, without respect to race or nationality, to age, occupation or position, until every one susceptible to the disease was affected. Slaughter reports from India that even domestic animals, especially dogs and cats, were not exempt, as they appeared to suffer from rheumatoid affections of the joints.
Although toward the end of the last century dengue once prevailed epidemically in the temperate zone, at Philadelphia, it must nevertheless be considered as a disease especially at home in the tropical and semi-tropical regions, where it prefers to haunt low lands, particularly along the sea-coast, leaving almost untouched more elevated places. Though nothing definite is known about its special cause, its history and symptoms evidently show that it is not only infectious, but also highly contagious, in its nature, and in consequence must be caused by the entrance of a specific poison into the system. This view is held by the great majority of physicians residing in the various localities of the globe where the disease has prevailed. But, contagious as it may be, it greatly distinguishes itself from other contagious diseases by almost never proving fatal. As dengue generally prevails in the summer season and disappears with the approach of cold and rainy weather, its cause is apparently subject to the influence of certain meteorological conditions.
DIAGNOSIS.—When dengue appears epidemically, it is distinguished from other diseases without difficulty. The only disease with which it might be confounded when appearing in a sporadic form is acute articular rheumatism. But even from this affection it may be distinguished in its earlier stage by the pains not being limited to the joints, as is generally the case in articular rheumatism, but being also present in the head, back, and loins. Dengue is, moreover, characterized by a general physical and mental nervous depression, while in rheumatism the mind almost always remains clear. In the latter stage the peculiar eruption and painful swelling of the superficial lymphatic glands in dengue decides the question.
It has frequently been stated that dengue resembles yellow fever, and some physicians have even regarded it as a mild form of this disease. In examining attentively, however, the temperature of the patient during the febrile stage, it will be found that while it steadily rises in yellow fever, it is remittent in dengue. There is, furthermore, a difference observed in the state of the pulse, which in yellow fever generally falls on the third day, while the temperature continues to rise; in dengue, on the contrary, the pulse rises with the temperature. In the condition of the stomach also dengue considerably differs from yellow fever, for while in the latter disease this organ is almost always irritable, and vomiting is very frequently present, it is but rarely affected in dengue. The urine in yellow fever very frequently contains albumen as soon as the third day; in dengue, almost never, so far as the analyses recorded enable us to judge. Finally, the absence of jaundice and the appearance of the eruption on the fourth or fifth day remove all doubt about the nature of the disease. There are a number of other points by which dengue may be distinguished from yellow fever, which we, however, forbear to enumerate, for the reason that those already mentioned will suffice for a correct differential diagnosis.
PROGNOSIS.—Dengue, as has been stated before, scarcely ever terminates fatally unless it is complicated by some intercurrent disease. The prognosis, therefore, is highly favorable.
TREATMENT.—Nearly all authors recommend a symptomatic treatment in dengue, beginning with a mild cathartic, mercurial or not, and followed by a mild diaphoretic. To relieve pain and procure sleep opium—either uncombined or in the form of Dover's powder—belladonna, camphor, assafoetida, valerian, etc. have been recommended by different physicians; liniments containing camphor or chloroform have also been used with advantage for the same purpose. Foot-baths have been recommended to relieve the headache. To relieve the stiffness of the muscles and the articular pains after the subsidence of the fever iodide of potassium appears to be a favorite remedy in the East. Colchicum combined with aconite is also recommended for this purpose, as well as artificial sulphur baths and massage. The nervous depression during convalescence is to be combated with tonics and with regulation of the diet. Quinia appears to be generally discarded as a remedy in dengue.