NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
22
Kostitchschew has found micrococci and bacilli. Saulljew by culti-
vating the blood of the heart of an animal dead of Rinderpest in
sterilized bouillon has obtained micrococci and bacteria inoculable to
mice and rabbits. He considers that the pathogenic microbe of Rinder-
pest is a bacillus, which is transformed into a micrococcus and again
assumes the bacillary form under certain circumstances. It gives a
greyish-white colour on Agar Agar, becoming afterwards citron coloured,
then red. The greyish-white colonies are the most virulent.
M. Piot, Veterinary Surgeon in the Egyptian Administration, in 1883,
announced that he had succeeded in attenuating the virus of Rinderpest
by heat to such a point as to give an inoculated animal only a slight
attack of the disease, after which, however, it became immune or protected.
Whatever may be the intimate nature of the virus of Rinderpest
and of its attenuation by cultivation and by heat, we are certain tha
it exists in every part of the animal body, in all the organs and tissues,
in all the fluids and in all the secreted and excreted matters—a fact
which proves that it is produced in enormous quantity by the sick
animal, and that one sick animal may in this way furnish an enormou
amount of it and thus form a very powerful centre of infection. The
virus is rejected from the animal continuously either by way of the
skin, nasal, buccal, genito urinary or respiratory apparatus, etc., etc.
If we add that it may be suspended in the atmosphere either by
adhering to particles of floating matter or suspended as dust, we may
conceive that an animal sick of the disease is surrounded by an atmos-
phere contaminated and contaminating. The major part of the rejected
virus contaminates the litter, mangers, food, water, etc., etc., and under
these circumstances may, under favourable conditions, be preserved
for a very considerable period of time. A sick animal is therefore
dangerous not only itself but also on account of the solid, liquid, and
gaseous materials which it contaminates.
When the virus of Rinderpest enters the system, it soon makes its
action felt, multiplying and giving rise to the first symptoms. The
medium period of incubation is from 4 to 10 days, but a longer period
from 20 to 30 days has been noticed (Lemaitre). The virus multiplies
and causes changes in the blood, which are soon accompanied by other
changes, chiefly localized in the integuments.
The question has often arisen whether the animal is dangerous
during the period of incubation, and at what date the virulence
appears. The answer to this question seems to be that very shortly
after the introduction of the virus into the system the virulence appears,
so at least the fact that a bull transmitted the disease during the period
of incubation would tend to show.
The experiments made by Semmer, and the post mortems of animals
inoculated for only 36 hours and which have evinced no sign of disease,
23
have shown that lesions quite characteristic of the disease were present.
This is very significant and would naturally lead us to the conclusion
that an animal is virulent and capable of transmitting the disease before
any symptom has been noted—a most serious matter for our considera-
tion in carrying out measures for suppression.
The virulence persists during the whole course of the disease, and
does not disappear even after death. It has been stated that it becomes
attenuated as death approaches, but there is great difference of opinion
on this point. However this may be, one thing is certain, and that is,
that it persists for a certain time after death.
What are we to say regarding animals which are recovered? In this
regard we may remark that in Europe few animals recover at the com-
mencement of a serious outbreak, and the same is the case in India in
serious outbreaks, although when the disease is of less intensity large
numbers do recover. The disease here, especially in the hot arid plains
where the temperature of the atmosphere rises to a point which is
acknowledged to distroy the virus, or at any rate to greatly attenuate it,
very frequently assumes a mild type, a benign form in fact, and
large numbers recover. This is equally the case where the disease has
approached the termination of an outbreak and the virus has apparently
become naturally attenuated. In such cases are we to consider that
virulence ceases when cure is brought about or even after this period ?
To reply to this question is not an easy matter. We may, however,
consider that virulence persists until the disappearance of the diarrhœa,
discharge from the eyes and nose, and salivation have entirely ceased ;
but we are not in a position to say whether the virulence persists after
complete recovery; in fact there is reason to believe that it does not.
Whatever the case may be, we must consider convalescent or recovered
animals as dangerous for a fortnight at least, as the virus may be borne
on the surface of the body in a virulent form for that period, and of this
fact numerous examples have come under my own notice.
The Rinderpest virus rejected by the diseased animals, as well as
that of the cadavers, may be conserved for a considerable time; its
vitality seems to persist more or less according to various conditions,
but however bad the conditions may be it may live for several days.
The study of this question is a very important one, as it dominates the
application of certain sanitary measures. How long does the virus
live ? On this point the observations vary very considerably, are nume-
rous and contradictory. According to some observers the virus is
preserved for days, months, and even years; whilst in the opinion of
others whatever the conditions, the preservation cannot exceed 30 days ;
and further this cannot occur unless the virus is preserved in sealed
tubes. It has been pretended that in buried carcasses the virus may
be preserved for months (Victor D' Azyr), or even during years, and that
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it is consequently dangerous to let animals graze where the cadavers
have been interred. It has also been stated that the cadavers of Rinder-
pest animals exhumed after some months of burial, may still transmit
typhus. This expression of opinion does not seem to be exactly true;
it is perhaps much too alarmist. In 1874 M. Visear D'Arras exhumed
some Rinderpest cadavers after 10 or 12 months of burial, and caused
ruminants to graze over and smell the debris with no result. M. Reynal
did not succeed in transmitting the disease by inoculating with mate-
rial from an animal 58 days after death. It appears, therefore, that the
cadavers, even when buried, do not conserve the virus for such a long
period as has been stated, but as the truth is not yet absolutely estab-
lished on this point, it is necessary for us to act with great prudence
with regard to it and to take every precaution. The flesh, fresh skins,
and in a general way all the fresh debris are dangerous, and for a certain
period may serve as a means of conveyance of the virus. But on this
subject, as well as on that of buried cadavers, the duration of the conser-
vation of the virus has been greatly exaggerated. The researches mention-
ed by Reynal give us a fairly exact idea as to the danger resulting from
the skin, horns, bones, and hair of Rinderpest animals. The skin of an
animal dead of Rinderpest has not any contagious property when tanned
or dried. No record of the introduction of the disease into a country by
the medium of tanned or dried skins has ever been published, and hence
it is not necessary to prohibit the importation of dried or tanned skins
from a country where Rinderpest exists, provided it is at some con-
siderable distance. In 1745, Courtioron tried to transmit Rinderpest
to two cows by means of very fresh skins removed from animals
dead of the disease, but did not succeed, and he concludes his remarks on
the subject of the experiment by saying " not regarding the experiment
which I have made as a reason to doubt the popular opinion, it may per-
haps be expedient to order that skins may be kept in an infected village
in a particular place and may be rendered saleable after a certain period
has elapsed." In 1769, Camper in Holland placed the fresh skin of a
Rinderpest cadaver in close proximity to two calves, but did not succeed
in transmitting the disease to them by this means.
Victor D'Azyr made attempts at transmission but was not successful :
he, however, did not consider his experiment conclusive, and counselled the
burial of animals dead of the plague in their skins. Other experiments
made by Camper in 1769 by inoculating with fragments of fresh skin proved
that six days after death of the animal they may retain their vitality.
Spinola, from what he has himself seen and from what Russian authori-
ties state, believes that fresh skins coming from a neighbouring country
may be dangerous, but not those from a distant country. Buniva has
observed the propagation of the disease by means of the hides. It has
for a long time been known that fresh skins are a fruitful source of the
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propagation of the malady, but how long do they remain dangerous ?
According to an experiment made by Camper they are virulent six days
after the death if the animals have been buried. According to Victor
D'Azyr, scraps of skin may cause the disease six months after the animal
has been buried. Loringer considers that fresh skins maintain their viru-
lence for eight days after their removal from the cadaver; hence it
follows that skins coming from a distance are not dangerous, especially
if well dried and salted.
Does the Rinderpest virus preserve its virulence for any length of
time on the surface of the litter, dung, forage, mangers, in the water,
discharges, etc. ? We are not. in a position at present to offer an opinion
on this point, although it is an immensely important one. It appears
that the virus deposited on the surface of solid bodies cannot be pre-
served for more than four or five days in the summer or 15 days in the
winter. And even this time may be abridged if they are exposed to a
continuous current of air, and if at the same time they are submitted to
the action of heat and the rays of the sun, or if the weather be cold and
humid, for then the process of putrefaction rapidly destroys it. In these
various cases the virulence does not extend over many days, generally
about 11, at least so it appears. The virus found in a stable where not
exposed to currents of air, and where the air is not changed, may remain
virulent for a longer period, according to some observers 8 to 10 days.
Placed in a flask it preserves its virulence for from 4 to 8 days, and if
the flask be hermetically sealed it does so for a slightly longer period.
It may also remain virulent for a longer time, 12 to 30 days, if herme-
tically sealed in a vaccine tube or placed between glass slides, particularly
also if placed in vacuo ; but in any case the virus remains virulent for a
much shorter period than does that of sheep-pox (variola ovina) or cow-
pox (variola vaccinia). The virus may preserve its virulence in water
for a time, the length of which remains to be settled. In the dung,
which is the richest receptacle, the germs may be rapidly destroyed by
putrefaction; at the end of a month they have been found to be inno-
cuous. Nevertheless it is necessary to take into account the assertions of
those who attribute to the virus of Rinderpest a more prolonged viru-
lence, and of these the most rational appear to be those of M. Chauveau.
"The expired air," he says, "is not the excretion which is richest in viru-
lent elements; indeed, it has been experimentally shown that it is poor in
comparison with others. The tears, discharge from the nose, saliva from
the mouth, milk, urine, and excrement more particularly contain an
enormous amount of the virus, and unhappily the pernicious properties
rejected on to the litter, dung, on the roads, stables, pastures, etc., may
remain virulent in the open air for several weeks. These are the most
dangerous vehicles of the virus, and those of which it is most necessary
to destroy the contagious action." But what can we think of those pre-
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tended cases in which cases of transmission obtained after prolonged
dessication for several years ? What credence is to be accredited to the
opinion which holds that infected stables may remain dangerous during
several years. What conclusion are we to draw from a fact of transmis-
sion attributed to the administration of an infusion of hay taken from a
stable where the disease had been present five months previously? What
importance are we to accord to successful experimental inoculation with
material kept for a year ? Is it not rational to think that there has been
some exaggeration, or that coincidences may have led to error ? Is it
not probable that if the virus enjoys the power of so conserving its viru-
lence, occidental countries to which the disease is imported could be only
freed from its ravages with the utmost difficulty, for notwithstanding
that a good system of disinfection be adopted, it is extremely difficult to
attack all the germs. We have already seen that Rinderpest virus does
not resist intense cold nor a temperature of moderate elevation, and hence
is only preserved in the stables, during the severe weather of the more
elevated and cold ranges of the Himalayas. The experiments of Semmer
and Archangelski have shown that it is sterilized by cold at 15° to 20° C,
and also by a temperature of 56° C. The sterilization of Rinderpest virus
is hastened by putrefaction, dessication, currents of air, æration and ven-
tilation, an elevated temperature, intense cold and light. In practice we
must have recourse to these means as far as is practicable without danger.
The sterilization on the contrary is retarded when the air is confined and
not renovated, when it is humid and fresh, where light does not reach the
virulent matter, when dessication and putrefaction are retarded.
Modes of Contagion. — We have already seen that Rinderpest
owes its development and propagation exclusively to the very active
contagious properties possessed by the sick, the products of their
excretion and debtis — properties which impregnate other animals and
by them conveyed to others again, as also is the case with people and
anything whatsoever in fact which has been in contact with the
sick, their excretions or their debris. Animals may contract the disease
after having been brought into contact in any way with an agent
impregnated with the contagious element. These agents are numerous,
and. the danger is imminent when sick and healthy animals frequent
the same places, live in the same grazing grounds, locality, village, or
neighbouring ones, if all communication between the sick and healthy
animal is not interdicted.
Rinderpest may be transmitted by immediate or mediate contagion
and also by inhalation. The disease is transmitted by direct contact of
healthy with diseased animals, and when an animal is placed near a sick
one it is exposed to contamination by each of the three methods. When
Rinderpest spreads from place to place, when it becomes epizootic, it is
in almost all cases transmitted by mediate contagion. It passes from
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one stable, farm, or village to another through the intermediary of
diverse solids or liquids, food, water, etc., etc., which are soiled with
contagious materials and which are smelt, licked, or ingested by animals.
The malady is also, although less frequently, transmitted by the
atmosphere, and in this particular it is well to decide or to enquire
whether the atmosphere which surrounds the sick animal is dangerous
at great distances. Accepting as demonstrated, for it is demonstrated
that the air may act as a medium for transmission of Rinderpest, we
should also recognize that although it has been stated that this medium
is capable of carrying the materies morbi for a distance of 500 yards, it
appears probable that it does not transmit to large distances. On this
point, in the localities where Rinderpest has been prevalent, it has been
noted that when due care has been taken, and the places carefully seques-
trated, no cases of the malady have occurred, although in close prox-
mity to others where Rinderpest has claimed several victims (Chauveau
Visear). The distance to which volatile contagion is possible would
seem, therefore, to be not very great. It naturally varies according as
the contagious atmosphere is very rich in virulent material, and whether
the contagium bearing atmosphere has been exposed to winds or to
current of air, and as to whether the malady is severe, more or less gene-
ral, and whether there are any obstacles around the centre of infection.
A wall, hedge, forest or hills may greatly retard the spread of the dis-
ease by the atmosphere; but I must repeat that in the majority of cases
it is not the air which is the most fruitful source of spread of Rinderpest.
Under ordinary circumstances the contagious zone does not exceed 20
to 40 metres. It is by ingestion that the disease generally propagates
itself.
M. Chauveau says : "I have demonstrated that the spontaneous eva-
poration of the most virulent matter taken from a subject attacked with
Rinderpest is incapable of drawing out any infections emanation. The
drops of a liquid which condense on the walls of a bell glass under
which this evaporation is conducted proves on inoculation to be devoid of
virulence, whilst the least particle of the material from which it has
been obtained gives Rinderpest when inoculated under the skin. I
have found moreover, in analyzing rigorously well-observed facts,
that contagion by germs sown in the air plays only a secondary role in
the propagation of the malady to a distance. It is particularly by ali-
mentation that this propagation is effected. The dejecta sown on the
roads, in pastures, ponds of drinking water, or transported to a distance
by means of animals or men who have trodden in them, infect the food
and water." A very good example of the spread of the malady by the
water supply is to be found at the end of this in an appendix, and came
under my own observation in the Kotkhai tahsil of the Simla district in
India.
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It is probable that the disease in the Himalayas spreads to a great
extent in this way, by the people pollutting the water-supply by throw-
ing into the streams or their feeders the carcasses of animals dead of the
malady.
It may be again repeated that it is contagion by ingestion which
plays the most important part in the dissemination of Rinderpest; the
virus excreted by the diseased, or arising from their cadaveric debris,
being preserved by external media and introduced into the system with
the food and drink ; and it is easy to divine that this conditions are
frequent and numerous where the disease exists in a part where sanitary
and precautionary measures are neglected. Animals may infect them-
selves either by licking the walls, mangers, racks, and other objects
soiled with the virus, or by eating food into which the virulent material
has fallen, or by drinking water to which it has gained access.
The principal means, agents, vehicles, or intermediaries which may
serve for the propagation of the disease are very numerous, and the
disease when it is introduced into an organism nearly always gains
access by means of the food, drink or air, these being contaminated in a
variety of ways, serving to transport the virus—forage placed either
above or below infected stables in store, grass from infected pastures,
forage and litter which has directly received the virus from the sick
animal, forage and litter trodden on by people who have been walking
amongst the sick, plants manured with dung from infected stables,
forage and litter which have directly received the virus excreted by the
patient or have been in contact with the cadaveric debris.
Drinking water may also be contaminated with the virus either from
sick animals drinking in it, or by the excrements gaining access to it, or
by skins or flesh from diseased animals having been washed in it, or by
animals being thrown into it after death from the disease, as is common
in India, and more especially in the hills, or by wild animals drinking at
it after a meal of the contaminated flesh.
The cadavers, skins, flesh and the various debris, so long as they are
fresh, also serve to convey the disease, either by animals smelling them
and thus introducing the virus into the respiratory passages, or by these
products having been deposited on the herbage or forage or by being
washed in water which is ultimately swallowed by animals; all objects
which have served to transport Rinderpest flesh are, therefore, dangerous,
being impregnated with the virus. Besides food and drinking water,
various other objects may serve as vehicles to contagion when they are
licked, or come into contact with animals, or when they are brought
into contact with food or water. Of these, we may cite mangers,
cribs, racks, all objects in soiled localities, sieves, watering places,
fastenings, grooming kit, clothing, roads, fields, pastures, carriages,
carts, manure and litter, urine, meat, various cadaveric debris, etc.
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Carcasses badly buried which carnivorous animals may disinter,
carnivorous animals after a meal on a dead Rinderpest carcass. We
may easily imagine the danger which the majority of these intermediary
vehicles may give rise to.
A single sick animal is capable of infecting a public drinking
place whence healthy animals may become infected; similarly it
suffices for sick animals to soil a pasture with their excretions and
secretions in order that it may be the means of infecting other
animals grazing over it five, six, or even twelve days afterwards.
Pastures are rendered dangerous when they have been manured with
litter which has been in contact or has been soiled with the virus from
sick animals. Conveyances, railway trucks, and the various utensils
which have been in contact with sick animals are dangerous, preserving
their infective properties for several days. Litter fæces, etc., are very
dangerous materials, being very rich in the virulent matter. Animals
which smell, lick, or ingest them become infected. Animals and
men who walk about on these materials carry the virus away on their
shoes and spread it about as they walk. In this manner also, dogs or
other animals walking about in a stable where animals are suffering
from the disease get their feet, skins, and hair impregnated with the
virulent material, and may afterwards soil water or forage which, when
ingested by healthy animals, will induce the disease. The same is true
of the human being, the owner, the veterinarian, and the men employed
in looking after the sick. If these persons are not very particular to
cleanse themselves, and more especially their shoes, they may, and often
do, carry away the virus, and by soiling roads, forage, water, etc.,
become unwittingly the means of spreading the malady amongst other
healthy cattle. It is really the boots of people engaged about sick
animals which are the most dangerous owing to the likelihood of their
cleansing being overlooked, and owing also to the material with which
they become soiled bearing such large quantities of the virus; and the
feet of animals are dangerous for the same reasons. Sheep may trans-
port the virus of this diseases in their wool without becoming themselves
affected with the disease; but it is probable that wool does not preserve
the vitality of the virus for long, and that when it has been dried, and more
particularly if also disinfected, it is not dangerous. Cadavers or debris
of Rinderpest affected animals which have been badly buried constitute
a danger. They may be disinterred by carnivorous animals and dragged
about over the herbage and soil it with the virus, so that healthy animals
grazing may ingest the poison and take the disease. Moreover carnivor-
ous animals when devouring diseased meat impregnate their lips, hair, and
paws with the virus, and may thus transport them from place to place.
Rinderpest may under certain circumstances be transmitted by
direct contagion. Healthy animals may infect themselves by licking