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 {884} 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 {885} 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.
{886}
RABIES AND HYDROPHOBIA.
BY JAMES LAW, F.R.C.V.S.
SYNONYMS.--Canine Madness, Rabidus Canis, Canis Rabiosa. _Greek_,
Lyssa, Lytta, Lyssa Canina, Cynolyssa, Hydrophobia, Pantephobia,
Ærophobia, Phobodipsia, Erethismus Hydrophobia, Clonos Hydrophobia,
Dyscataposis. _French_, Tetanus Rabien, La Rage, Toxicose Rabique.
_German_, Wuth, Hundswuth, Tollwuth, Wuthkrankheit, Hundtollheit.
_Italian_, Rabbia, Arabiata. _Spanish_, Rabia, Rabiosa. _Swedish_,
Hundsjuka. _Roumanian_, Turbarea.
DEFINITION.--Canine madness is an acute infectious disease, supposed
to arise spontaneously in the genus Canis (dog, wolf, fox, etc.) and
Felis (cat, etc.), but transmissible by inoculation to the other
Mammalia and to birds. It is characterized by a long period of
incubation, by exaggerated reflex excitability, by disorder of the
intellectual, emotional, and other nervous functions, by change of
habits, by extreme irritability of temper, by optical and other
delusions, by spasms of the muscles of the eyeballs and throat, by
paralysis, and by more or less fever. The disease runs a short and
almost without exception fatal course.
HISTORY.--Plutarch claims that hydrophobia was first recognized by the
Asclepiadæ, and Homer's allusions to the malign dog-star and to
Hector's acting like a raging dog have been quoted as implying a
knowledge of rabies. We find no certain reference to the affection,
however, until we come to Democritus and Aristotle, in the fourth
century B.C. The latter clearly describes the disease and uses the
name lytta, but, singularly enough, claims for man an exemption from
the general susceptibility to the infection by inoculation.[1] From
that date to this the successive outbreaks, sufficiently noteworthy to
secure a place in history, are so numerous and widespread as to show a
continuous prevalence of the malady in the Old World, and, since the
early part of the eighteenth century, in the New.
[Footnote 1: _Historia Animalium_, lib. viii. cap. 22.]
GEOGRAPHICAL DISTRIBUTION.--Rabies is more prevalent in temperate
regions than in the tropics and Arctic Circle, but this is common to
all animal plagues propagated solely or mainly by contagion, and is
manifestly due chiefly to the density of population, the activity of
commerce, and the free movement of men and animals in the temperate
zone. That a hot or cold climate is incompatible with rabies is
disproved by its prevalence under the tropics in Southern China,
India, Abyssinia, the West Indies, Peru, Chili, and Brazil, and in the
Arctic Circle in Northern Greenland, Lapland, Siberia, and Kamtchatka.
On the other hand, many {887} islands and secluded regions in the
temperate zones maintain a continued immunity or have been invaded
only recently by the introduction of infected dogs. We may instance
the Hebrides, Australia, Tasmania, New Zealand, South Africa, West
Africa, the Azores, St. Helena, and, until the last half century, La
Plata, Malta, and Hong-Kong. The disease is well known throughout
North Africa, Arabia, Syria, Turkey, and Asia generally, in Ceylon and
other of the East Indian islands. It is also notorious that even when
unusually prevalent its progress is often abruptly arrested by a
considerable river, and Schrader and Virchow both notice that though
it ravaged both banks of a river, yet the islands in the river
escaped, as was notorious of the islands in the Elbe during the great
Hamburg epizoötic in 1852-53. While, therefore, rabies prevails most
extensively in the more civilized countries and in large cities, yet
we can point to no geographical area in which the contagion has failed
to spread among those bitten by rabid animals, nor to any locality in
which the disease has been shown to arise spontaneously from
unwholesome conditions of climate, soil, or general environment.
ETIOLOGY.--We know of but one efficient cause of rabies--namely,
infection. Yet as many conditions are believed to favor its extension,
or even to determine its spontaneous eruption, it is necessary to
speak of them shortly.
As shown above, climate cannot be charged with the generation nor
diffusion of rabies. Many countries formerly thought exempt are now
known to suffer. The following may be named: The East and West Indies,
Syria, Egypt, Cyprus, Siberia, the lands north of the Baltic, and
South America. Others manifestly maintain their exemption only because
the morbid germ has not yet been introduced.
Certain seasons undeniably show a far wider extension of the disease
than others, but such epizoötics are not limited to a particular
season or year, and, unless cut short by human intervention, cover a
succession of years of the most varied climatic character, spare
inaccessible or secluded islands in the very centre of the outbreak,
and the cycles of prevalence will succeed each other, in place of
occurring simultaneously, in closely adjacent countries subject to the
same climatic vicissitudes, but separated by narrow seas. Even a broad
river destitute of bridges usually abruptly arrests an epizoötic, and
protects the land beyond lying under precisely the same general
influences. In this connection may be quoted the recent great
epizoötic of 1856-72 in England, which succeeded, but did not
accompany, that of 1851-56 in Germany. Prof. Röll reports the
extraordinary prevalence of rabies at Vienna in 1814, 1815, 1830,
1838, 1842, and 1862--years remarkable for diversity rather than
uniformity of climatic characters.
Popular opinion refers rabies to the extreme heats of summer, and each
year dogs are muzzled or otherwise confined by order of municipal
authorities during the dog days, though left at liberty throughout the
rest of the year. In 1780, Andry observed that the coldest and hottest
months furnished the least number of cases, and later Hurtrel
D'Arboval claimed that in France dogs suffered most in May and
September, and wolves in March and April. Bouley claims that the
majority of dogs suffer in March, April, and May. The following
statistics are interesting in this connection: {888}
_Cases of Rabies in_
WINTER. SPRING. SUMMER. AUTUMN.
Dec., Jan., March, April, June, July, Sept., Oct.,
Feb. May. Aug. Nov.
Dogs 755 857 788 696 (Bouley).
Men 17 25 42 13 (Boudin).
The increase of cases of rabies canina in the spring and summer
months, as shown by the above statistics (7-15 per cent.), cannot
reasonably be attributed to the influence of the weather, since even
the strongest advocates for spontaneity would at once decline to claim
any such ratio of spontaneous developments. The increase must
therefore be mainly, if not altogether, due to the increased number of
inoculations; and these latter are provided for in the jealousies and
quarrels in the troops of males that follow each rutting bitch in
spring, the principal period of oestrum in the canine female. The
infection spread in this way in early spring tends to remain more
prevalent throughout the hot summer months.
With regard to the greatly enhanced mortality in man during the summer
months, as shown in Boudin's statistics for France, in the absence of
any genuine hydrophobia in man apart from inoculation from a rabid
animal, it may be attributed to three principal causes: 1st. The bites
sustained from rabid dogs in spring and early summer, when the disease
is most widely spread among these animals, will give rise to
hydrophobia weeks or months later. 2d. In the warm season the body is
more thinly clad and the hands and other portions are more frequently
left bare, so that the teeth are less likely to be cleansed of the
virulent saliva by passing through the clothes before entering the
skin. 3d. The languor, fever, and nervousness attendant on extreme
heat tend not only to hasten the activity of any disease-germs
actually present in the system, but also strongly favor the increase
of that nervous fear which so often generates a fatal
pseudo-hydrophobia (lyssophobia) in persons that have been bitten by
dogs.
Hunger, thirst, and spoiled food are invoked as causes of rabies, yet
in the East, where the dogs are the scavengers of the cities and often
suffer severely from hunger and thirst, eat the most offensive
carrion, and drink the foulest water, the disease has a very
restricted prevalence, while in South Africa and Australia the outcast
and sheep-dogs, often the victims of starvation and thirst, entirely
escape. Bourgelat, Dupuytren, Majendie, Breschet, and others have
cruelly destroyed dogs by privation of food and water and by exposure
under a broiling sun, but no rabies, nor anything resembling it, was
produced. Dogs perspire little and suffer severely from heat, but
there is no evidence that this can develop canine madness. It is
claimed that Rossi of Turin developed rabies in cats by withholding
food and drink, but, as he furnishes no inoculation-tests confirmatory
of its virulence, the claim cannot be endorsed. Experiments with an
exclusive diet of salt meat, putrid meat, and water only have failed
to produce rabies.
The large preponderance of male dogs attacked with rabies has been
constantly remarked by writers. Of 1990 rabid dogs reported by
different authors, 1746 were males and 244 females--a ratio of more
than 7 to 1. This excess of males attacked is much higher than the
ratio of males in the dogs of the districts drawn upon. Thus, Bourrel
found a {889} ratio of 6 rabid males to 1 rabid female, while in his
patients generally the proportion was 4 to 1. Leblanc found that 14
per cent. of the male dogs went mad, while but 1 per cent. of the
females suffered. That sex is no protection against inoculated virus
is shown by the frequent inoculation of castrated dogs of both sexes.
The excess of male subjects may be attributed mainly to the frequency
with which these bite each other when following a female in heat, and
the respect of all alike for the latter sex. Even in the rabid dog the
sexual instinct rises above the propensity to bite in the early stages
of the malady.
Toffoli claims that he has caused spontaneous rabies by shutting up
several dogs in a loose box with a bitch in heat and allowing them to
fight for the prize. Weber and Leblanc have noticed similar
occurrences. But Greve and Menecier have repeated the experiments with
a contrary result; so that it remains probable that when successful
the victims had already been inoculated before they were shut up.
Moreover, the seclusion of male canine animals for a lifetime in
menagerie cages, often adjoining those of their corresponding females,
has never been known to induce rabies.
The bite of the violently enraged dog, and the bites mutually given
when following a rutting bitch, are popularly supposed to cause
rabies; but if this were the case, the disease must have been
universally prevalent. The idea that the bite of a dog will cause
hydrophobia should that dog at any subsequent period go mad is a
similar delusion. Men doubtless occasionally develop lyssophobia under
such an influence, but animals do not contract genuine rabies.
Dogs are alleged to have gone mad from violent suffering after an
operation, and cats from being scalded or robbed of their kittens, but
all such causes are continually operating without such effect, and
when in a solitary case rabies develops, it can only be looked on as a
coincidence.
Much popular prejudice exists against certain breeds, and the
Pomeranian has been virtually ostracised on account of its supposed
liability to rabies; but statistics show that the liability to
contract the affection bears a relation to the exposure rather than
the special breed. Eckel, Pillwax, and Hertwig found that dogs kept as
house- or watch-dogs, and most pampered and confined, are the most
liable, while St. Cyr and Peuch found the greatest number of cases
among those running at large and allowed the freest exercise.
There is a popular belief that the bite of the skunk (_Mephitis
mephitica_) is always rabific. Rev. H. C. Hovey describes a number of
cases of infection from this animal,[2] and John G. Janeway has
reported other instances.[3] Both claim that the disease is
spontaneous in the skunk, and Mr. Hovey holds, on very insufficient
grounds, that the affection is a distinct variety of rabies (rabies
mephitica). The facts seem to warrant only the conclusion that skunks
in certain districts of Michigan and Kansas have had rabies
communicated to them, and follow the rabid impulse to bite other
animals and men. The Mephitinæ abound in the Eastern States, but we
never hear of them stealing up and biting men or dogs, nor of the
latter contracting rabies from skunk-bite. Eastern dogs frequently
kill skunks and sustain bites, but do not thereby contract rabies.
Even in Kansas this evil {890} influence of the skunk-bite was unknown
until 1870, showing that it is not inherent in the climate nor soil,
but has been presumably imported. The spontaneity of the affection is
assumed, not proved.
[Footnote 2: _Amer. Jour. of Science and Art_, May, 1874.]
[Footnote 3: _New York Medical Record_, March 13, 1875.]
In the above epitome of alleged causes we find nothing proving the
spontaneous evolution of rabies. The prevalence of the affection in
wolves, foxes, jackals, cats, skunks, etc. proves nothing for
spontaneity, more than its existence in the dog. In all these species
of animals the malady develops the dread propensity to bite, and thus
in all alike provision is made for the perpetuation and propagation of
the malady. Unless a previous attack by a rabid animal has been
observed, owners usually insist that their dogs have contracted the
malady spontaneously, yet a rigid scrutiny will almost always reveal a
strong probability, at least, of inoculation. The rabid dog wanders
far from home, and sometimes accomplishes wonderful feats of leaping
to reach his victim, so that his presence in a district is not even
suspected, and animals thought to be safely secluded inside high walls
suffer from his fangs. He is more inclined to bite and rush on than to
stay and devour, and thus small animals, like the skunk, when bitten
may survive to propagate the disease in places to which a dog could
not possibly find access. Much circumstantial evidence makes strongly
against the theory of spontaneity. Thus, the immunity of the islands
of the Elbe in the very midst of a severe and protracted epizoötic,
the continued immunity of the Hebrides and of Malta, each famed for
its indigenous race of dogs, for long centuries, during which the
malady prevailed at frequent intervals on the adjacent mainlands, and
the continued exemption of South Africa and of the Australasian and
other islands, in the face of the counter-fact that the affection
persisted after importation in the West Indies and South America,
speak strongly for the doctrine that the introduction of a
pre-existing germ is an essential condition of the evolution of the
disease. The following statistics of cases which entered the Berlin
Veterinary College furnish further corroborative evidence. There
entered the college,
In 9 years, 1845-53, inclusive, 278 rabid dogs.
" 1854 4 " "
" 1855 1 " dog.
" 1856 1 " "
" 5 years, 1857-61, inclusive, 0 " "
The average for each of the first nine years was a fraction less than
31. In the two last of the nine the cases rose to 68 and 82, and this
led early in 1854 to an order for the muzzling of all dogs, which was
rigidly enforced by the police. The disease was promptly suppressed,
the two cases in the two succeeding years being probably due to
infected kennels or to importation from without. The results in Eldena
(Fuertenberg) and Holland (Van Capelle) are equally conclusive. The
inefficiency of some orders for the muzzling of dogs makes nothing
against these facts. A law on the statute-book is not always a law in
force, as I saw in Alfort and Lyons in 1863; the dogs wore their
muzzles only in honor of the periodic visits of the commissionnaire of
police, and rabies prevailed.
The great majority of competent observers of to-day deny, or at least
strongly doubt, the occurrence of the disease apart from inoculation.
Without assuming to decide the question for all times and places, it
may {891} be safely asserted that there is no sufficient proof of such
an occurrence in any recent time.[4]
[Footnote 4: Mr. Sâzé, a former student, informed me that boys in
Japan produce what is believed to be canine rabies by administering to
dogs a fungus (bukeryo) found growing on a coniferous tree. The dogs
do not all seem to die, but are usually killed by way of precaution.
The symptoms are those of delirium, with a propensity to bite, and the
disease is assumed to be communicable, though no facts are given to
show that it is so. This popular fancy has all the air of a popular
fallacy, but as the counterfeit attests the genuine, it shows the
familiarity of the Japanese with true rabies.]