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Cattle-plague in China
THE
JOURNAL OF
COMPARATIVE PATHOLOGY AND
THERAPEUTICS. ~-~~-~~--~~~
VOL. XXI I.-No. 3. -
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PRICE
SEPTEMBER 30,1909. -
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2S.
6d.
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CATTLE-PLAGUE IN CHINA.
By H. E. KEYLOCK, F.R.C.V.S., Shanghai, China. THESE notes do not attempt to throw any further light on the disease from the clinical, pathological, or bacteriological points of view. They are written solely with the object of being of some assistance to those who may have the disease to contend with, and, if my observations, failures, and successes attain this, the notes will have served their purp9se. I t may be interesting to mention that the disease is, as far as can be gathered, indigenous to the whole of China; it is continually smouldering in the country, and, with absolutely no preventative measures to arrest its spread or actions taken to eradicate the disease, it seems extraordinary, considering the mortality of the disease, that there should be any cattle left in China. It is possible that this may be accounted for as follows: In this part of the country, namely, the Yangtsze Valley, innumerable creeks intersect the whole district, and cattle and water buffaloes are used solely for agricultural purposes. In an average-sized village the biggest stock owner would not possess more than two beasts and five sheep. (The dairy farms in the vicinity of Shanghai are excepted.) In a locality abounding in waterways the latter are naturally the means of transport, hence the cattle do not travel as beasts of burden or traction. These points mean more or less efficient isolation. In other parts of China, where water transport is not available, transport, generally speaking, is carried on by ponies, mules, donkeys, and camels. N
(;ENERAL ARTICLES.
Enormous herds of cattlc arc seen on the Manchurian plains, but these herds belong to a particular tribe, and wide tracts of country separate them. In Shanghai and its vicinity cattle-plague makes its appearance periodically, travelling from dairy to dairy. It is introduced by animals brought here for slaughter, but, I believe, principally by means of feeding materials; in fact, there is no other way than the latter to account for some outbreaks in local dairies. Dairy cattle are fed principally on cotton cake, bran (both made locally), and rice straw, and infection by means of the cotton cake and rice straw is quite obvious. The writer has seen water buffaloes and cattle suffering from the disease working in the local cotton mills. The cakes as they are made are placed just outside the circle round which the animal walks, and the discharges from an infected animal splash over the cakes. The usual situation in which to place a sick animal of any description is under the lee of a straw rick, and hence the source of infection of two of the principal feeding materials in the local dairies is quite apparent. The Chinese admit that the disease is infectious, but they do not admit that it is possible to prevent infection. They are very philosophic over an outbreak, and sum it up by, "b'long very bad joss (luck) have got that deblo (devil) inside." They further believe that one attack usually confers immunity, but they do not recognise that this immunity is absolute, as they do not distinguish this disease from others. They do not make post-1Ilortems or recognise the diagnostic value of pathological changes. Having such a disease to deal with some ten years ago, with, at that time, no effective agent, slaughter being quite out of the question, the only possible solution was effective isolation of the infected. It has been the writer's experience that the period of incubation in naturally infected animals is never longer than seventy-two hours, that invariably the first symptom is a rise of terpperature, and that the beast which shows a rise of temperature does not naturally infect others until after the lapse of twenty-four hours. In an infected dairy the method adopted was to obtain two sites, other than the infected dairy, where cattle could be kept. The thermometer was accepted as being absolute in the detection of the disease. The temperature of all the animals was taken twice daily, and those animals appearing as normal were removed to site NO.2. During the following three days all animals in site No. 2 which showed a rise of temperature were returned to the infected dairy, and after the same period the remainder, showing a normal temperature, were removed to site NO.3. Short, sharp rises of temperature occur in cattle from inexplicable reasons, and all those exhibiting such in site No. 3 were returned to site No. 2. If serum or defibrinated blood from an immune animal is not obtainable this method remains the best at one's dispoc:al, but it often breaks down through unauthorised communication between the three sites. \Vhen the outbreak of the disease occurred in S outh Africa the work of the various commissions was very carefully watched; bile, whether glycerinised or not, was at once discarded for the following reasons :-
GENEJ
195
I. No immunity is granted until eight or ten days after inoculation, during which time all the beasts in contact may contract the disease. 2. It possesses no properties of a curative nature, neither does it modify an attack. 3. Fdr some unexplained reason the disease is extremely likely to follow an injection of bile in three or four months, and the disease then arising runs a most virulent course. (Recent local observations have shown that it is possible for glycerinised bile to actually communicate the disease, with its heaviest fatality.) When serum inoculation was introduced in South Africa a quantity was purchased from that country and arrangements immediately made to produce it locally. The preparation of anti-rinderpest serum does not demand the resources of an extensive laboratory, but simply a beast that has recovered from an attack, sterile glassware, and a sufficient quantity of blood from a beast that is suffering from the disease. The method adopted for the production of serum has been as follows : PrejJaration if tile Serum-jJroducing Animal.-An animal is obtained that has recovered from a naturally contracted attack of the disease, or one that has successfully emerged from a simultaneous injection of serum and virulent blood. In the selection of the animal, for obvious reasons, the following conditions should influence one's selection : The result of an examination of the heart and pulse, and the condition, age, and size of the animal, for, of course, a big, strong, young animal wiII withstand successive bleedings much better than a thin, old, poor one. A suitable animal having been obtained, its temperature is taken morning and ev.ening for three days, and at the en,d of that period, if its temperature has remained normal, an injection of 50 cc. of virulent blood is given. (The temperature of all serum or virulent blood-producing animals is taken morning and evening, and blood is not abstracted for serum, or virulent blood is not injected to raise immunity, unless the temperature has remained normal for at least forty-eight hours.) The result of the inoculation of virulent blood is, as far as the clinical symptoms are concerned, by no means constant, but in 90 per cent. of the cases the temperature rises within seventy-two hours and remains above normal from three to ten days. A secondary rise on the twelfth day is very common, but it does not persist after forty,eight hours. (This secondary rise has always been waited for before .abstracting blood for serum, or before giving another injection of virulent blood.) The height of the rise of temperature does not depend on the size of the dose of virulent blood, but, I think, entirely on the degree of susceptibility of the animal injected. Being guided by the temperature, the first inoculation of virulent blood is followed by an injection of 100 cc. of the same material, then by 500 cc., followed by 1000 cc. When the temperature has subsided to normal, after the last injection, blood is then abstracted for serum. This abstraction is repeated twice more. After the third abstraction -of blood the animal receives, in one injection, a dose of 2000 cc. of
(;ENb~RAL
ARTICLES.
virulent blood, again followed by three abstractions. This second series is followed by an injection of 3000 cc. of virulent blood, alld again three abstractions. 5000 cc. of virulent blood may be injected into an immune animal without any ill effect, but successi\'e and increasing doses of virulent blood, it is claimed, strengthen the protective qualities of the serum obtained. Serum from some individual beasts is undoubtedly stronger than that obtained from others, and for this reason it is advisable to mix all serums obtained on the same date. To ascertain the strength of a serum from any given beast, or to standardise serum, needs the resources of an extensive experimental station, and this is beyond the usual facilities of a practitioner. Unless subsidised, experimental work is practically impossible, and the attempt to produce methods that would enable one to deal with the disease without the standardisation of the serum has always been kept in view. Unless stated otherwise, the results of inoculations, as given later, are results obtained without any attempt at standardisation of the serum. Collection, PreparaHon, and Storage of Serum.- The usual method is to throw the animal, dissect and expose the jugular vein, pass the finger underneath it, insert a small canula, and convey the blood into flasks by means of india-rubber tubing. This procedure takes a considerable time; struggling on the part of the animal is liable to displace the canula, the vein thickens at the seat of operation, and the flow of blood is often irregular and slow, owin~ to the mouth of the canula being blocked by a valve. These are small objections, easier to overcome in theory than in practice. The method recommended is to drive three poles firmly into the ground at a distance of 2 feet from each other. Place the animal to be bled alongside these poles, with the head turned round the erid pole, shave and disinfect the skin over the jugular groove, distend the vein by means of a cord below the site of incision, and make one bold incision through skin, connective tissue, and wall of vein by an ordinary bleeding fleam. The incision can hardly be too bold with a fleam, and, if bold enough, the blood flows in a strong steady stream into a big glass funnel, which directs it to the collecting flask To arrest the flow of blood it is usually sufficient to seize the edges of the wound, cleanse thoroughly, remove the cord, and allow the animal to straighten its neck. Should there be any h~morrhage after the animal has been allowed to straighten its neck, a couple of stitches is all that is necessary. This method of abstracting blood is quickly performed; it renders throwing the animal unnecessary, and it keeps all instruments, glassware, etc .. away from the ground. The first incision should be made as close to the head as possible, and subsequent incisions close to the previous one, following the jugular towards the heart. From an animal of 800 Ibs. or over ill weight, 4000 cc. of blood is withdrawn, and from an animal of 500 Ibs., 2000 cc. Provided the serum-producing animal is liberally fed, the repeated abstractions of blood have little effect upon its condition. Preparation of tlte Serttm.-Long cylindrical serum tubes, fitted with glass caps and holding about 500 cc. each, are the most convenient receptacles to receive the blood in, but they are not necessary. Any glass bottle or jar will answer the purpose, provided it can be thoroughly sterilised. The blood is allowed to stand for twelve hours
GEN ER /\L ARTICLES.
197
in a cool place (in tropical countries an ice box is advisable), after which period the serum is drawn off by means of a sterile pipette into sterile bottles, and ~ per cent. ac. carbo!. pur. is added. The acid causes a precipitate of albumen, but this precipitate does not affect the serum or plug the needles when injecting. The bottles in which the serum is received are then corked with corks that have been boiled for half an hour on three successive days; the bottle necks are wiped dry and dipped in hot sealing wax (or ordinary paraffin dur.). Serum stored in this way will keep for a considerable period. It was found that South African serum bearing dates of preparation five years previously had not lost ih -cfficacy, although it had been subjected to temperatures varying from 50° to I I 5° F. Virulent Blood and its Collectioll.-As a result of many observations and experiments the writer has drawn the following deductions. I t is admitted that in some instances these deductions are merely surmises, but the results of inoculations detailed later seem to justify them. I. The degree of virulence of infective blood varies, but ICC. (the smallest practical working dose) will confer a fatal form of the disease as readily as 100 cc. 2 . The degree of virulence does not depend upon the stage of the disease in which the animal is when the blood is taken, but blood taken from an animal suffering from the sequela! of the disease may not be virulent. 3. Blood appears to possess a more consistently high virulence on the third day of fever following infection. 4. Blood after abstraction retains its virulence for seventy-two hours (possibly longer), and there appears to be no gradual decline of the virulence, or, if there is such a decline, it is not apparent when the blood is injected into a susceptible animal. Accepting the above as being correct, the practice adopted for obtaining virulent blood has been to obtain two animals and inoculate them with virulent blood. (In this country, where the disease is indigenous, it is always possible that a single animal selected for inoculation may prove to be immune through having had the disease previously, and then one's series of virulent blood is lost. To prevent this two animals are inoculated.) vVithin seventy-two hours of the inoculation, and usually within forty-eight hours, the animal's temperature makes a sudden rise, and remains above normal until the sudden drop, which indicates death, appears. The highest point to which the temperature rises is usually on the third day after the first rise of temperature, and it is this period which has been selected for the abstraction of virulent blood. The animal is thrown, the carotid artery exposed, severed, and a bent glass tube carries the blood to the collecting flasks. (5 per cent. of a 5 per cent. solution of cit. of potassium is added to the blood to prevent coagulation.) The carotid artery is recommended in preference to the jugular vein, as invariably more blood is obtained, and the jugular flow is often irregular and slow. Further, accepting deduction No 2, with the possibilities that this opens up, one naturally wishes to obtain a certain standard of virulence, and, therefore, the actual infective blood as it is in the body should be obtained before any physiological
GKNEI
changes can take place. A post-mortem on the animal that has supplied the virulent blood should always be held, and the blood should be examined microscopically. Well-marked lesions must not be expected, and the absence of lesions distinguishing other diseases is of great importance. The Injection of Vimlent Blood.-It is injected subcutaneously. It has been injected intravenously, but the latter method has no advantage over, but rather minor disadvantages against, that described below. There is no difficulty in injecting a small quantity, say 100 cc., but when larger quantities have to be injected there are three points that are liable to cause trouble : I. Disengaging the syringe from the needle, refilling the syringe, replacement of the syringe, and movement of the animal, are all very likely to lead to contamination of the blood with extraneous substances, thereby causing abscesses at the seat of inoculation. (When contamination has occurred, usually the blood is not absorbed but forms large putrid abscesses.) 2. It is very easy to use too much force when injecting blood, in which case connective tissue is broken down and the blood is very slowly absorbed. 3. It takes a considerable time to inoculate a large quantity, say 2000 cc. The method recommended is to place the animal to be injected within a "crush," and fasten it with the head halter only. The bottles containing the blood to be injected are placed in a box, which is suspended 6 feet from the ground and immediately over the animal's back. An india-rubber tube carries the bl ood from the bottle to the hypodermic needle. It will be found that the force of gravity alone is quite sufficient to drive the blood into the tissues, but the force is not sufficient to break the latter down. By this method the blood appears to be more readily absorbed; it takes a very short time to inject a large quantity, and the injected blood from the time it leaves the artery of the animal from which it was abstracted touches nothin g that can not be made sterile. The most convenient sea ts for the injection are the middle of the neck , either side of the scapular spine, R inches above the olecranon, and anywhere over the ribs. \Vhen a large quantity has to be injected all these sites should be visited. Slight pressure immediately over the puncture will immediately arrest any exudation of the injected material. In the majority of cases the injected animal's temperature rises within six to eight hours after the injection, which rise ~ubsides within twelve hours. \Vithin the next seventv-two hours the temperature again rises, and it remains elevateu fo~ variable periods, but neve r l onger than eleven days. After the temperature has fallen to normal fifty-two hours should elapse before a bstracting blood, as slight secondary ri ses for about twenty-four hours are liable to occur. Steriiisation of Flasks, Hottit's, and Jllstru lllents.- The best and most effectual method is by means of dry heat. An ordinary sheet iron box with a false botto m can be made by any local coppersmith. A hole is made in the top of the box for the reception of a bored cork carrying a centi g rad e thermometer. Around the top and sides
GENERAL ARTlCLl<.S.
199
of the box two thicknesses of a medium-weight horse blanket are sewn, and an ordinary gas flame water boiler supplies the heat. Flasks and bottles, after having their necks plugged with cottonwool, are placed in the box, and the temperature is raised and maintained at 1700 C. for one hour. If serum preparation is to be carried out on a large scale, and serum tubes are to be used, it is scarcely practical to sterilise them in this way, and the following method may be substituted. Thoroughly wash the tubes and fill to the brim with a 5 per cent. solution ac. carbo!., which solution is replaced by a 2! per cent. solution twenti·four hours before use. The latter solution is not removed until immediately before receiving the blood. Syringes of a capacity of not less than 100 cc. should be obtained, and such syringes should be easily taken to pieces and have interchangeable parts. Syringes, needle'>, and metal instruments are boiled, and pipettes, india-rubber tubing, etc., are stored in a 5 per cent. solution of ac. carbo!. When using india-rubber tubing, syringes, etc., for virulent blood they are well washed in boiled water to remove all traces of the carbolic solution. Administration of SerU1Jl.- The site selected for the injection of serum is about 4 inches behind and above the olecranon, and this selection is made because here the skin is thin, causing a saving in the breakage of needles. The hair is clipped off, and the skin washed and douched with a 1/1000 solution of perchloride of mercury. This solution dulls the edges of the needles, but the cheapness and efficacy of the solution more than balance the lit.tle extra trouble in sharpening the needles. To prevent contamination of the serum, the syringe is filled by means of a bent glass tube which, together with a small air tube, runs through a bored cork placed in the neck of the bottle containing the serum. The bent glass tube carries a few inches of rubber tubing, on which is placed a stopcock, and in the end of the rubber tubing is inserted the mouth of a broken needle. In 95 per cent. of injections no reaction, either temperature or local, follows, and the serum is very rapidly absorbed. To describe the method recommended for using the serum on an infected herd it will be well to sketch the typical and almost constant conditions found when called in. One is told that an animal has died, and one or more contact animals are exhibiting diarrhcea and other symptoms. A post-mortem is at once made, but the lesions shown vary enormously, and almost invariably the first beast that dies does not show anything approaching the extensive lesions found in the beasts that subsequently succumb. There is often nothing to observe beyond a little inflammation of the fourth stomach. This is apt to make one feel guarded in making a diagnosis, but it is usually found that the condition of the remaining in-contact beasts leaves no room for doubt. An examination of these in-contact animals is made, and their temperature taken. The animals may then be divided into the following classes:Class A.-Refuse all food, fetid gaseous diarrhcea or dysentery, recumbent head and ears drooped, coat staring, watery discharge from eyes and nose (mucoid discharge uncommon in China), acceler-
200
GENERAL ARTICLES.
ated breathing, grunting, in great pain, temperature from 103° F. to sub-normal, pulse thin, weak, and wiry. Class B.~Refuse all food, diarrhcea or dysentery has just commenced, abnormal thirst, respirations accelerated, pulse strong and hard, temperature 104° to 107° F. Class C.-Animals with half their normal appetite, high temperature; otherwise normal. Class D.-Full appetite, no symptoms beyond a high temperature. Class E.-No symptoms and temperature normal. The above simply represents some of the clinical symptoms of the disease and its gradations, but is thus expressed to give the results of injections of serum. Classes A. and B.-Injections of serum in any quantity, either intravenously or hypodermically, will have no effect. If it is thought necessary that an attempt should be made, 300 cc. of serum may be injected into the jugular and repeated in twelve hours, but the case is practically hopeless. Class C.-Should receive 200 cc. of serum intravenously, followed by 100 cc. subcutaneously in twenty-four hours if the animal does not appear worse. These animals will exhihit other symptoms; they require careful nursing and stimulants, and recoveries are in proportion to the attention they receive. About 20 per cent. of recoveries may be hoped for. Class D.-Should receive 100 cc. of serum subcutaneously, which dose is repeated in twenty-four hours. About half of the animals in this class will exhibit other symptoms, the remainder showing no symptoms beyond the high temperature. About 50 per cent. of recoveries may be looked for. Class E.-I t is impossible to state if these animals are infected or not, as they may be in the incubation period. The temperature of the animals that are in this incubation period will rise within fortyeight hours. The method recommended is to give all animals in this class 50 cc. of serum, and to those that show a rise of temperature within the forty-eight hours before referred to give as soon as possible 100 cc., and follow it with another 100 cc. in twenty-four hours. Those that do not show this rise of temperature have not contracted the disease, and the 50 cc. of serum will confer absolute immunity upon them for nine days following the injection. If another dose of serum be given the immunity is renewed. but I am not in a position to state for how long, nor can I offer any opinion as to the effect of a third dose of serum. If, on the other hand, this second dose of serum be not given. and the animals are still exposed to infection, the disease is contracted, usually any time between the ninth and fifteenth day following the first inoculation. If, immediately on the rise of temperature following this naturally contracted attack, another dose of 50 cc. be given, the temperature will run the typical course of the disease, but no other symptoms are exhibited; in fact, it would be impossible to state that the animals were infected were it not for the evidence of the thermometer. Following the above lines in this class,90 per cent. of the animals will be saved. It is curious to note that if a milking cow has not received a dose of the serum the milk is totally arrested within twelve hours of the rise of temperature, whereas if the animal receives a dose of serum and then becomes naturally infected on
GENERAL ART1CLES.
201
the ninth to tenth day, with the usual temperature reaction, the milk is not arrested. Further, those animals that go through a mild attack, which is sufficient to arrest the milk supply, \Viii, if this attack does not last longer than ten days, return to their normal yield of milk. It is believed that those animals exhibiting a temperature reaction are rendered immune for life. In one experimental case an injection of 50 cc. of virulent blood, given nineteen months after, failed to set up the disease; it did not even cause a temperature reaction. The defibrinated blood of these beasts may, in cases of emergency and where there is no serum to be obtained, be successfully employed in arresting an outbreak, provided it is used in doses of not less than zoo cc.
I'"
~~i
Dltiry No.
Owner.
I'~~ ~i§ ~ 0
I .~.:;~ Nlt",uerl ~';l~ of I "t!"
11 ",~;;
II ~ ~
Cows.
,
Deaths...
s.;o De
%)
'1l';:j ;;; g ",.~~~
Percentltye.
Re",,,,'hs.
I
-----1---' ~~.~ --:~~., --,-----------w.
s·1
1
R.
2
R. W. S.
3 4
5
~
",,-<
21
1
1
15
3
24
I
II\)
Ii
I Two control calves left uninocnlated: both died.
--
-
1
17
o
o
H
o i , -I
A. U.
24
()
()
18
2
-
-
;\lr8 F.
23
3
1
4
0
-
-
R. W.
s.
I
i
1
6
R. W, S.
22
7
J. C, F.
3
II
D.W.C.
4
4
4
!l
R. E. T,
2
2
2
10
A. W.B.
2
I)
0
1
11
HongKong Dairy Farm
H
1
1
2
0
-
i
0
7
1
-
-
1
2
0
---
-
-
-
-
-
-
-
-
-
0
-
-
0
-
-
I
- - - - - - - - - - - - - - - - - - -I - - - - - 151 18 17 I lJ4 6 I n'24 I
The above table shows the result of 151 inoculations in eleven different dairies. In dairy No. I certain experiences had to be gained, hence the comparatively heavy loss amongst those that showed clinical symptoms subsequent to inoculation. These results were obtained between five and six years ago, and many other outbreaks have been treated in the same manner since that time, all of which confirm the earlier results. Simultaneous blOcltlation.-Serum gives but a passive immunity, which is of very short duration, and although by its means animals may be successfully carried through a naturally contracted attack, thereby conferring an active immunity, the method of infection is unsatisfactory, inasmuch as the disease is not under one's control. Animals mayor may not become infected. It is not practical when
2C2
GENERAL ARTICLES.
dealing with a large number of animals, and for other obvious reasons. Simultaneous inoculation (a dose of serum and a dose of virulent blood, given at the ~ame time on opposite sides of the body) has been tried by many workers, and I believe discarded by all. My initial experiments were more than satisfactory, and were confirmed by subsequent experiments. The results when put into practice worked out as follows : -
~
Dose
Number
Dose
[«ted.
Sen"".
1;;3
50 cc.
10 cc.
3
10
50 cc.
10 cc.
No second inoculation testing serum
8
100
liO cc.
10 cc.
4 Two deaths
Three deaths
4
-1
188
:if! cc.
10 cc.
88 Eleven deaths
28 Four deaths
.j
35
iiO cc.
10 cc.
Inoc'n-
I
of
of
Death,.
Virulent
Conclusion Drau'n.
Blood.
Ages Three weeks to two years
R
18 Two deaths
0
Reaction insufficient.
0
Reaction insufficient.
70 Sixteen death.
21
Reaction strong.
too
0
17
Reaction strong.
too
Remarks.
0
Reaction insult:cient.
21
15
3
One of these has been proved immune to the disease by a hypodermic injection of virulent hlood five years after, and many have withstood natural infection.
()
6
:iO cc.
10 cc.
Followed hy 50 cc. sernm two days after.
0
Reaction severe.
too
'j
t)
50 cc.
Followed hy 50 cc. serum and 10 cc. virulent blood "ix days after.
0
Reaction severe.
too
35
50 cc.
10 cc.
Followed hy almost daily doses of Eolerum in 50 to 100 cc. doses, accoruing to severity of reaction.
17
Reaction severe.
too
!I
;)t)
,iO cc.
10 cc.
"\s the 8;' lot.
H)
Reaction severe.
too
10
10
Y"adous
10 cc.
Ascertainihg
0
Reactions various.
11 ,
U:;
Various These beasts were inoculated with various doses Of serum and blood in order to confirm Series 10, but the blood was proved non· virulent by the control animals. For certain reasons no further injections were given.
0
13
26
20 cc.
10 cc.
1:3
52
2.1
CC.
10 cc.
In accordance with results obtained in Series 10.
16
14
157
80 cc.
10 cc.
lIIaking an allowance for weight of animals.
38
(j
------
GENERAL ARTICL1cS.
20 3
Virulent blood, and blood described as virulent, was proved to be so by control animals. The serums used were many and various, some prepared in South Africa, some in Manila, and the remainder made locally. Different serums were used in the same series of inoculations, but no difference could be noted in the results obtained. The locally produced serum was always prepared in the manner described. Where the remark "Reaction insufficient" appears, it means that some of the animals showed no rise of temperature or other reaction, and that the remainder gave but a slight reaction. (From subsequent inoculations I have reason to believe that an appreciable reaction may not be necessary to confer a permanent immunity.) The remark" Reaction too severe" indicates that although there may have been no deaths in the series the symptoms were very severe, leaving the animals in a debilitated condition, and causing a good deal of anxiety as to what the result would be. The above series showed that the reactions were not more consistent by reducing the dose of serum, and indicated that a further trial should be given to 50 cc. and bigger doses of serum. . Number S er'!Cs [noruNo. lated.
Dose of
Dose of
SerU'lIl.
Virulent Blood.
I I
De
!
I
4
15
94
50 cc.
10 cc.
16
44
50 cc.
10 cc.
17
25
50 cc.
10 cc.
18
11
50 cc.
10 cc.
19
150
60 cc.
10 cc.
42
20
61
75
CC.
10 cc.
18
21
28
85 cc.
10 ce.
0
22
27
100 cc.
10 cc.
0
Two of these deaths were complicated with piroplasmosis. lOne death complicated with piroplasmosis.
'I
4 2 1
In series Nos. IS, 16, 17, 18, 21, and 22 the reaction and losses were considered satisfactory, but it was difficult to understand the heavy losses in Nos. 19 and 20. In Nos. 15 and 16 piroplasmosis first made its appearance, and three out of the eight that died exhibited hzemoglobinuria. (Piroplasmosis is indigenous in the country, but apparently does not assume a virulent form, probably because immunity is acquired during the first year of life.) The dose of 85 and 100 cc. was not carried further, as the reactions were practically nil, and it is hardly practicable to use such a large quantity of serum on a large number of animals. Up to this point the dose of 10 cc. of virulent blood had been accepted as suitable, as a result of the initial experiments. I further believed that it was immaterial whether I cc. or 100 cc. was used as the infective dose, and did not think it practicable to lise in the field a smaller dose than ICC. In case the dose of virulent blood was incorrect, the following
GENERAL ARTICLES.
inoculations were made, a dose of serum being given the animal's weight : &";es No.
Nttrnberof Anirnal., Inoculated.
Dose of SerurI!.
I
Dose of Virulent Blood.
In
proportion to
De'tfh.~.
I I
-~---------I------
2:3
2
I
2" cc.
ao ce. 60
I
1 cc.
1
1 cc.
13
1 cc.
1
40 ce.
1 cc.
34 I)
3:> ce.
23 2()
i
27
:3
45 ce.
1 cc.
28
aU
flO ce.
1 cc.
This series being most unsatisfactory, it was then decided to ignore the weight of the animals and inject bigger doses of serum, and also serum and virulent blood given on different dates.
---------------.----------------------------------------------Series \
I
. o.
Number of Animals l npc1llnted.
2U
117
GO cc. serum and 1 cc. virulent blood
fi7
:30
209
7:3 cc. serum and 1 cc. virulent blood
7G
:31
78
100 ce. serum and 1 cc. virulent bloot!
34
32
8
50 cc. serum, followed by 1 cc. virulent hlood two days
4
:33
2
100 cc. serum, followed by 1 cc. virulent blood three days
1
34
24
:3fl
5
:3t;
:38
Inoculatcd with.
'I
'
Deaths .
----J-------.-------~
:37
Ii
38
94
39
;~3
40
7
after the serum
after the serum 100 cc. serum, followed by 1 cc. virulent blood four days after the serum 2.> cc. serum, followed in two days by 75 ce. serum and 1 cc. virulent blood 25 cc. serum, followed in three days hy 75 ce. serum and 1 cc. virulent blood 2.'; cc. serum, followed in four days hy 75 cc. serum al1l1 1 cc. virulent blood 50 cc. serum, followed in two days by 50 cc. serum and 1 cc. virulent blood 30 cc. serum, followed in three days by 75 cc. serum anrl 1 ce. virulent blood 50 cc. serum, followed in four days by ,,0 ce. serum and 1 cc. virulent blood
11 3
I" 4 38
7 Ii
The majority of the above animals were required for export; they were going to a country infected with cattle-plague, and it was desired to immunise against the disease before shipment. With boats waiting for their transportation, it was not possible to make as many experiments as one would have wished; hence, often a fresh series had to be inoculated before the results of the last series could be obtained. Further, having once started, it was, for certain reasons, impossible to discontinue, in spite of the heavy losses. The simultaneous inoculation being a financial failure, it was discarded, and an injection of serum alone used. This injection of
GENERAL ARTICLES.
2°5.
!oerum alone was used on somewhere about I 1,000 head of cattle, with the most satisfactory results. On the face of it, the latter statement appears to be of little value, but it means a great deal when one considers that ill this part of China wherever one gathers together twenty or thirty head of cattle, cattle-plague will certainly break out amongst them. Cattle are brought to the sheds in an infected condition, and the thermometer will not distinguish a beast in the incubation period. Given healthy beasts in the first instance, their very food may infect them, and, indigenous as the disease is, contagion assails them from all sides. Again, the buying and storage sheds were badly infected, yet the serum conferred an immunity on those not purchased in the incubation period, and practically all those purchased in this incubation period recovered with further doses of serum. The above is mentioned merely to substantiate the writer's opinion that the serum and its preparation does not account for the failures in simultaneous inoculation, and that therefore one must turn the attention to the virulent blood. The inferences drawn from the results obtained were as follows : Serulll.
The protective activity of serums, as obtained from different serum-producing animals, varies very little from a practical point of I.
VlelV.
2. To ascertain the value of each serum before using it would need the maintenance and resources of a large experimental station. If the first deduction is correct it is not necessary to ascertain the value of serums, and if it is not correct serum is beyond the' scope of practical utility to the average practitioner, unless he is able to ,?btain serum from an experimental station.
Virulent Blood. I. Blood taken from an animal at any stage of the disease (provided serum has not been given) will convey the disease in a fata 1 for111. 2. Though all infective bloods are capable of giving the disease in a fatal form, yet some of these bloods will not convey fatal infection if given in conjunction with serum. In other words, serum is able to nullify the effects of the causal organisms or their products if the former are in a certain condition. 3. Therefore the degree of virulence of blood as taken from an infected animal must vary in its intensity. A.s it did not seem possible to ascertain the degree of virulence of the blood, simultaneous inoculation was discarded, until my attention was drawn to a report by Professor Arloing. l I n this article Professor Arloing claims that it is possible to attenuate the virulent blood to such a degree as to make it innocuous, whilst retaining sufficient virulence to confer some immunity. Further, that by means of repeated dnses of bloods of increasing virulence (1es~ attenuation) it is po'ssible to confer an active immunity. He found that-Defibrinated virulent blood heated to 50° C. for thirty minutes gives the disease in I cc. doses, but not in t cc. doses (Blood I). 1
"Bulletin de la Soc. des Sciences Yet. de Lyon," .Tanuary and Fehruary 1(IOli.
206
GICNICRAL ARTICLES.
Defibrinated virulent blood heated to 50° C. for thirty-two minutes gives the disease only in doses of I cc. (Blood 2). Defibrinated virulent blood heated to 50° C. for thirty-five minutes gives the disease in a benign form in 2 cc. doses (Blood 3). Accepting the above, it was decided to make a few experiments, not with the object of conferring immunity by means of the blood alone but by using the latter in conjunction with serum. Believing that the virulence of bloods varies, and that the highest point of virulence is from the second to the fifth day of fever following artificial infection, I decided to take all virulent blood during these days and attenuate it according to Professor Adoing's method. Animals Nos. I and 2 were so situated as to prevent natural infection by any means, including their food. It will be noted that no serum was given to these animals, as I wished to ascertain whether it was possible to attenuate the virulent blood, and, if so, whether these injections of attenuated virulent blood would confer on the animals an immunity sufficient to enable them to withstand a further injection of unattenuated virulent blood. The deductions drawn from Series A. (p. 207) were:I. That no appreciable immunity was granted by either of the first two inoculations in Nos. I and 2. 2. That Blood 2 in doses up to 4 cc. does not confer sufficient immunity to enable the animal to withstand a dose of virulent blood. 3. That Blood I, even up to 10 cc. doses, does not confer sufficient immunity to enable the animal to withstand a dose of virulent blood. (See secol)d inoculations in Nos. 10, II, 14, 15, and 16.) 4. That Blood I, in doses over 4 cc. given in conjunction with serum, possibly confers sufficient immunity to withstand a dose of virulent blood. After the above results, there were many points that needed further investigation, and certain doses of the attenuated blood should have been definitely fixed, but unless one is working with experimental cattle it is not possible to do exactly what one wishes, and one has to be content with the best possible under the circumstances. The best that could be done was to see if deduction NO.4 was correct. At the wish of the owner simultaneous inoculation with serum and unattenuated virulent blood was also effected, and the latter was useful for comparison. From the inoculations in Series B. (p. 208) it appeared that ;I. The larger doses of Blood I moderated the reaction to unattenuated virulent blood more than the smaller doses. 2. That this reaction to unattenuated virulent blood might be still further lessened by a larger dose of Blood I or a les!:> attenuation of the virulent blood. In other words, obtain if possible a more marked reaction to the first inoculation. Before making any alterations in the degree of attenuation or dosage of the attenuated virulent blood, it was decided to make further inoculations with 10 cc. of Blood I. The inoculations with the unattenuated virulent blood were given at the wish of the owner.
20 7
GENERAL ARTICLES.
S eries .d . .
.~" "1
I
!
1-
FHI ~T
Inocu· lated wtth.
'C-
~
IXOCGLATIOX.
Type of Re(Mtion and Remarks.
--
-~~-
SECON]) I NOCULATION.
bwculatcd with.
1'ypc of Reaction and R emarks.
THIlIIJ
IXOCULATl(lX.
Inoculated 1vith.
Type of Reuction and Re,/ia1·ks .
1 cc. virulent hlood 1 cc. virulent hlood
Usual symptoms, followed by death Usual syml'toms, followetl by dea th Temperature reaction only
Conclu:-;ion Drawn .
--~--- -
1
:I cc.
None
1 cc.
None
2
2 ce. B. 3
None
1 cc.
None
1 cc.
None
2 ce.
None
None
4 cc. B.l
None
2 cc. virulent blood
12 ' 1 cc. R2 50 cc. serum
None
2 cc. B.2
None
2 ce. virulent blood
1J
None
4 ce.
None
2 cc. virulent blood
Los. of appetite and diarrhcea j no t emperature. Possibly not a rinderpest reaction
10 cc.
10
1l.3
!
B.1
50 cc.
B.1 B.2 B. 1
serum
11
2 ce.
R1
50 cc.
serum
2 cc.
B.2
50 cc. serum (Portion of serum wasted) 14
7 cc. B. I 50 cc.
serum
B.2
B.l
Temperature only
15
6 cc. B.l 50 cc. serum
None
10 cc.
None
Hi
:3 cc.
None
10 cc.
No temperature, but latter irregular. No appetite. D i a r r 00h a. Dysentery No reaction
B.1
,30 cc. serum
B.l
B.l
2 ce.
virulent blood
Satisfactory.
Typical attack of dise !ts~ . Reaction far too ~ev e re. Death Reaction very severe, followed by
Not satisfactory.
U,ual syml'toms, followetl by death
Not sati , factory .
Not sat isfactory.
2 cc. Temp e rature Doubtful. virulent reaction antl blood con s id e rable "ystemic disturbance. No other sylnpI toms I Typical 2 cc. t em- Not satisvirulent peratur~ r eo factory. action blood and other It"llal reaction t oo
2 ce. virulent blood
bevere
Had
not
rt··
covered from previollS re-
""ot ,atisf,~ctOl'Y.
action. Death
17
4 cc. B.I 50 cc. serum
None
2 ceo virulent blood
18
5 cc. B.I 50 cc.
None
2 cc. virulent blood
T e mp e ratur e only; excellent reaction
Hel,t]:'.·
X cc.
None
2 cc. "irulent blood
No r eaction
DOllhtful.
serum
19
, B. l
50 cc. serum - -- _.-
Doubtful.
factory .
208
GENERAL ARTI CLE S.
Series B. FIRST INOCULA'fION
- - - - - - , - - - -- - --
I noculatcd with.
T ./fPC of Reactim
and &11.,wk8.
SECOND I NOCULATION.
Conclusion D rawn.
1 -------- -- ------ - - --
T ype of Reaction und &111«1·1.:s.
Inoculated 1!lith.
20
5 cc. virulent blood 30 cc. serum
second Temperature only. No R eaction sat isinoculation fact ory.
21
5 cc. virulent blood :)0 cc. serum
Temperat ure an
second No inoculation
Not satisfactory.
22
,j cc. vir ulent hlood .')0 cc. serum
Temperature, loss of aprotite, and diarr rea. Too
No second inoculation
Not satisfactory.
No. 22
Satisfactory.
severe.
As No. 22
Not satisfactory.
Z;{
A~
2-1
-1 cc. B , 1 .')0 cc. serum
2 cc. virulent blood
,,-
Temperature on ly '\ severe, extend· iog over nine I days
~, l
6 cc. B. 1
2 cc. virulent blood
Temperature over seven days; partial loss of appetite
21i
l> ce. B. 1
50 cc. seru m
2 ce. virulent hlood
Temperature over five days; slight loss of appetite
:li
10 cc. 11. 1 :)() ce. serum
:3 cc. virulent hlood
T emperat ure over six days; d ial'rhrea one
2t!
10 cc. B . 1 50 ce. serum
2 cc. vir ulent hlood
Temperature over four days; diar r hrea four days
!l9
10 cc. B. 1 30 cc. serum
2 cc. virulent bloo<1
Temperature over three ,lays only
30"
10 cc. v irulen t Temperature seven 2 ce, virulent blood. blood days 50 cc. serum
.)0 ce. serum
* Inoculate<1 with virulent blood as no B . 1 avai~ahl e . fourth day of fever, t herefore con clusion of no value.
I I
I I Symptoms were
I
not severe enough t o cause any anxiety. Mayall be classed as satisfactory.
Received another
20 9
GENERAL ARTICLES.
r:. I
.£:'"
~eIRST
INOOCLATION.
"
SEOOND INOOULATION. --
~
'2
inocul«ted with.
~
-,~~-----
Type of Renetion and Remarks. ~~-----~-
Inoculated ~vith.
Type of Reaction and Remarks.
Conclusion Drawn.
-----~- ~~----~~- ~~--~----
31
10 cc. B. 1 50 cc. serum
-
2 cc. virulent blood
Temperature over three days only
Satisfactory.
32
10 cc. B. 1 50 ce, serum
-
2 cc. virulent blood
None
Doubtful.
2 cc. virulent blood
No temperature reaction or further symptoms. Died ou six th day. Post-mortem. Rinderpest
33\ 10 cc. B. 1 50 cc. serum
I
Uncertain. Tern· perature irregular; diarrhcea two days
I
-
10 cc. virulent Too severe. hlood Death.
-
-
Not satisfactory_
35
10 cc. virulent Very severe. blood iJO cc. serum
-
-
Not satisfactory_
3(;
10 cc. virulent Temperature over days. blood eight Too sever~. 50 cc. serUln
-
-
Not satisfactory_
37
10 ce. virulent Too severe. blood Death. 50 cc. serum
--
-.
Not satisfactory.
Temperature only six days
34
50 cc. serum
10 cc. B. 1
Uncertain. Temperature irregular
2 cc. virulent blood
3!l
10 cc. B. 1 50 cc. serum
None.
2 cc. virulent Temperature only. Not satisfactory. blood Death.
40
10 cc. B. 1 50 cc. serum
-
2 cc. virulent blood
Temperature and other symptoms. Death.
Not satisfactory.
10 ee. B. 1 50 ce. serum
-
2 cc. virulent blood
Temperature only nine days
Not satisfactory.
42
10 ce. B. 1 50 ee. serum
-
2 ec. virulent blood
Temperature only seven days
Not satisfactory.
43
10 ee. B. 1 50 ce. serum
Temperature only
2 ce. virulent blood
Temperature con- Doubtful. tinued from first inoculation for seven days
44
10 cc. B. 1 50 cc. serum
45
10 ce. B. 1 50 ee. serum
Temperature ir- 2 ce. virulent regular. Doubtblood ful 2 ee. virulent blood
38
41
50 cc. serum
I
Satisfactory.
Temperature only six days
Satisfactory.
Temperature only six days
Satisfactory.
The results of this series were not satisfactory. It seemed that sufficient immunity had not been conferred by the first inoculation. It was decided to attempt to obtain more reaction to the first o
GENERAL ARTICLES.
210
inoculation by (I) less attenuation of the virulent blood (Blood 4 and Blood 5), and (2) a bigger dose of Blood I.
Series D.
]
FIRST INOCULATION.
'"
~
'c>
~
Inoculated witk.
Tupe of Reaction and Remarks.
SECO~])
I
Inoculated witk.
ISOCULATIO:-I.
Conclusion Drawn.
Type of Reu,ction a1ul Remarks.
I - - - '-- - - - - - - - - - - - - - ----,-
i 2 ec. virulent
..Iii
nee.B.5 50 cc. serum
None
47
5ce.B.5 50 cC. serum
Temperature irregular only. Doubtful
48
10 cC. B. 5 50 cc. serum
Temperature only 12 cc. virulent five days blood
49
10 cC. B. 5 50 cc. serum
Doubtful. Tem· perature irregular
50
5cc.B.4 50 ee. serum
51
5ee.B.4 50 ee. serum
blood
2 co. virulent blood
Temperature only four day"
Satisfactory.
Temperature only seven days
Satisfactory.
None
Inoculated with a temperature of Satis· 103'4°. factory.
2 cc. virulent blood
Temperature only six days
Inoculated with a temperature of 103'6°. Satis· factory.
None
2 ee. virulent blood
Temperature only six days
Satisfactory.
None
2 ce. virulent blood
Temperature only eight days, and diarrhrna
Too severe.
I
i
52
10 cc. B. 4 50 ce. serum
Nonel
2 ce. virulent blood
None
53
10 ce. B. 4 50 ec. serum
None
2 ee. virulent blood
Temperat\lre four days
Satisfactory.
54
15 ee. B. 1 50 ec. serum
Temperature only six days
2 ce. virulent blood
None
Satisfactory.
55
15 cC. B. 1 50 ce. serum
Temperature only two days
2 cc. virulent blood
None
Satisfactory.
2 cc. virulent blood
Temperature only three days
Satisfactory.
2 cc. virulen t blood
None
56
20 ee. B. 1 50 cc. serum
57
20 cc. B. 1 50 cC. serum
I
None None
i
i
-
It
was believed this beast had received a simultaneous iniec· tion before, but uncertain.
A
}lost· mortem could not be made.
I I
I
58
20 ce. B. 1 50 cc. serum
A thin, poor beast in bad physical condition. Died on fifth day after inoculation, with no visible symptoms of the disease.
It was then considered that the best results were obtained from the injection of IS cc. of Blood I and that this should be confirmed. Unfortunately, circumstances over which I had no control made a slight alteration in the virulent blood, inasmuch as citrated blood in place of defibrinated blood was used on Nos. 64 to 71, both numbers inclusive.
GE,NERAL AR'llCLES.
2 I I
Series E. :-;~;COND INOCULATION
FIRST INOCULATION.
~~ Inoculated--~ype (If Rwction with. and Rem',rks.
Inoculated with.
'I'
I j
Type of Reaction and Remarks.
--:,-------- ----------I-------i----------------59 I 15 ee. B. 8 Temperature irregu-12 ee, virulent Piroplasmosis. Death. U "ual 50 ee. serum
lar on two days
60
15 ee. B. 8 50 ee. serum
Temperature irregu1ar on four days
2 ee. vinllent blood
Piroplasmosis. Death. symptoms very severe.
Usual
61
15 ee. B. 8 30 ce. serlun
Temperature irregular on four days
2 ee. virulent blood
Piroplasmosis. Death. symptoms very severe,
rsual
62
15 ee. B. 8 ~O ee. serum
Slight rise. Doubtful
2 ee. virulent blood
Death. Piroplasmosis. symptoms. ~ery severe,
rsual
63
15 ee. B. 8 50 ee. serum
Slight rise, thirtysix hours
2 ee. virulent blood
Piroplasmosis. Death. symptoms very severe.
l'sual
()4
15 ee. B. 7 50 ce. serum
None
2 ee. virulent hlood
Piroplasmosis. Death. symptoms very severe.
Usual
65
15 ce. B. 7 50 ee. serum
:None
2 ce. virulent blood
Piroplasmosis. Fever extending over four days. Redwater. Not a severe attack.
66
15 ce. B. 7 50 ee. serum
Temperature irregular on five days
2 ee. virulent hlood
Piroplasmosis. Death. symptoms very severe.
67
Hi ee. B. 7 50 ee. serum
~one
2 ce. virulent bloo(l
Piroplasmosis. very severe.
Usual symptoms Recovery.
15 ee. B. 7 50 ee. serum
Temperature irregu1ar on eleven days
2 ce. virulent hlood
Piroplasmosi". very severe.
rsual symptoms Death.
115 ee. B. 7 , 50 ee. serum
None
2 ce virulent blood
High fever teu days after inoculation of virulent blood, lasting for three days only. No other symptoms. Piroplasms found in the hlood during the fever.
15 ce. B. 7 50 ce. serum
None
2 cc. virulent hlood
Piroplasmosis. very severe.
Usual symptoms Death.
71
J5 ce. B. 7 50 ce. serum
None
2 ce. virulent blood
Piroplasmosis. very severe.
Usual symptoms Recovery.
72
15 ce. B. 7 50 cc. serum
None
2 cc. virulent blood
Piroplasmosis. very severe.
Usual symptoms Recovery.
73
15 cc. B. 6 50 ee. seruin
None
2 ce. virulent hlood
Temperature irregular four days only.
74
15 ce. B. 6 50 ce. serum
None
2 ce. virulent 'blood
Steady rise and decline of temperature extending over six days.
75
15 ee. B. () 50 ce. serum
None
2 ee, virulent blood
Steady rise and decline of temperature extending over ten days,
76
15 ce. 'B. I) 50 ce. seruD).
Temperature days
2 ee, virulent blood
Steady rise and deeline of temperature exten(ling over ten days. -
77
15 ee. B. 6' 50 ee. serum
None
2 ee. virulent blood
Temperature two days. ~eeondl\ry rise Oil tenth day to normal on sixteenth day.
78
15 ce. B. G 50 ce. sernrn
Temperature days
2 ce. virulent hlood
Steacly rise and decline of tempera, ture extending over five days.
68 ,
6!J
,u
-------
hlood
two
six
symptoms very severe.
i
----~--
212
GENERAL ARTlCI.ES.
Piroplasmosis is indigenous in China, and in my experience has never caused any serious loss; it therefore must be assumed that all cattle are immunised naturally when calves. In one or two previous instances the simultaneous inoculation has awakened the latent infection with a fatal issue, but never so seriously as in this instance. Perhaps one or two beasts out of a large number have succumbed to the combination, but from the above series it appears possible that the death roll may be heavy. I am not prepared to say that the virulent blood given did not contain piroplasms, and it would be a bold statement to affirm that blood taken from any beast in China did not contain the organism. These beasts were divided in three different houses :In House I. there were in all twenty-three beasts, of which number eighteen had been the subjects of cattle-plague previously, the disease either having been contracted naturally or given artificially. The remaining five appear in the series above as Nos. 59 to 63. In House I I. there were in all twenty-two head, of which number thirteen had been the subjects of cattle-plague under the same conditions as in House I., leaving nine (Nos. 64 to 72), which we were attempting to immunise. The above beasts' ages were from eighteen months to four years. In House III. there were nine yearlings (previously immunised by simultaneous methods) and six calves (Nos. 73 to 78), all about six weeks old. The virulent blood given in the three houses was exactly the same, and 1000 cc. of the same blood was utilised to further fortify an animal for the ultimate production of serum. On the latter the blood had the usual effect, viz., a rise of temperature and nothing further. The reaction given by the calves (House III.) was nothing but a temperature reaction; the appetite and bowels were unaffected. Piroplasms were found in the blood of those cattle from which films. were taken, including the calves. Fifteen days after the injection of virulent blood one beast out of the eighteen mentioned as being immune in House I. refused its food; its temperature was taken, and cattle-plague immediately suspected. The animal died, and the post-mortem revealed cattleplague. Two days after two more were affected in House I I.; one died (post-mortem, cattle-plague) and the other recovered, recovery being assisted by serum. The infection of these beasts proves that the virulent blood used carried the cattle-plague organism in addition to the piroplasm, and it further indicates that the immunity conferred by a slight attack is not absolute in all animals. I have proved beasts to be immune to a hypodermic injection of virulent blood six years after a simultaneous inoculation, and this is the second case in which occasional beasts have proved themselves to be non-immune some time after a simultaneous inoculation (in this case three and a half years). There can be no doubt that some animals possess more natural immunity to the disease than others, for some animals give no reaction to the simultaneous inoculation, and a subsequent dose of virulent blood fails to infect, yet the same simultaneous injections can convey a fat,al attack to another animal.
GF.N~; ](AL
AR'IICLES.
21
3
I ndigenous as the di sease is in this country, and in view of the absolute and usually lifelong immunity that is conferred by a sharp attack, it is not difficult to believe that a certain degree of immunity may be passed from dam to offspring, and, if this is so, the varying degrees of susceptibility as found in different animals may be accounted for.
PRELIMINARY NOTE ON THE TRANSMISSION OF EAST COAST FEVER TO CATTLE BY INTRAPERITONEAL INOCULATION OF THE SPLEEN OR PORTIONS OF THE SPLEEN OF A SICK ANIMAL.
By Dr K. F. MEYER, Pathologist, Government Veterinary Bacteriological Laboratory, Pretoria. As the result of the investigations of Robert Koch,! A. TheileJ} and others, it was found that East Coast fever could not be transmitted by injections of large or small quantities of blood, even although the infected , blood contained enormous numbers of the characteristic parasite, piroplasma parvum. This is a feature of the disease which serves to distinguish it from Texas fever or common redwater, and although Koch and his assistants also attempted to reproduce the disease by other means, such as the subcutaneous or intrajugular inoculation of spleen pulp and material from lymphatic gland (these materials being selected amongst others for experiment because these organs contain an enormous number of Koch's granules, which they considered to be a stage in the life cycle of the piroplasm), none of their experiments were successful. Theiler's experiments on similar lines also gave negative resuits with regard to transmissibility, and hitherto the only known method of reproducin g the disease has been by the agency of infected ticks. During the study of the genesis and development of Koch's granules I have noticed that the ha:mopoetic organs contain at the commencement of the disease granules or intracellular bodies which differ from those seen in these organs during the later stages. Those granules seen in the incipient stages appear before piroplasms are observed in the blood stream. It was noticed when collecting material for my experiments that the operation for the removal of lymphatic glands, spleen, and portions of the lymphatic glands was accompanied with little or no risk in the case of South African cattle, provided that the usual antiseptic precautions were observed. At the same time it was ascertained that the excision of these organs did not alter the ordinary course of the disease. The general outline of the technique is as follows : 3_ Laparotomy is performed on the near side ; the preparation of the site for the operation is as usual. To minimise the risk of infection, I "Reports on Rhodesian Redwater or African Coast Feyer," Salish1ll'Y, l!lO:3. "The Agri· cultural Journal," Cape of Gooa Hope, Vol. LXXIII., H10:l, and Vol. XXJV., 1904. "Archiv. f. Tierheilkunde," H104. "Deutsche l\Iedizin, IYochenschrift, " 1!l04, p. 140:;, and 1901\, p. 18(j5. 2 "Annual Report of the Government Veterinary Bacteriologist, " 1!l03·04, IH07·0H. "Rho· desian Tick Fever: Report of the S.A.A ..l.S.," Johannesburg, 1!l0,t, " Details will be publishtd in a later report.
JOURNAL OF
COMPARATIVE PATHOLOGY AND
THERAPEUTICS. ~-~~-~~--~~~
VOL. XXI I.-No. 3. -
--
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-
-
----
-~~-~--
---
--
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PRICE
SEPTEMBER 30,1909. -
-----
-~
~-
-
----
-
--.----
2S.
6d.
------
CATTLE-PLAGUE IN CHINA.
By H. E. KEYLOCK, F.R.C.V.S., Shanghai, China. THESE notes do not attempt to throw any further light on the disease from the clinical, pathological, or bacteriological points of view. They are written solely with the object of being of some assistance to those who may have the disease to contend with, and, if my observations, failures, and successes attain this, the notes will have served their purp9se. I t may be interesting to mention that the disease is, as far as can be gathered, indigenous to the whole of China; it is continually smouldering in the country, and, with absolutely no preventative measures to arrest its spread or actions taken to eradicate the disease, it seems extraordinary, considering the mortality of the disease, that there should be any cattle left in China. It is possible that this may be accounted for as follows: In this part of the country, namely, the Yangtsze Valley, innumerable creeks intersect the whole district, and cattle and water buffaloes are used solely for agricultural purposes. In an average-sized village the biggest stock owner would not possess more than two beasts and five sheep. (The dairy farms in the vicinity of Shanghai are excepted.) In a locality abounding in waterways the latter are naturally the means of transport, hence the cattle do not travel as beasts of burden or traction. These points mean more or less efficient isolation. In other parts of China, where water transport is not available, transport, generally speaking, is carried on by ponies, mules, donkeys, and camels. N
(;ENERAL ARTICLES.
Enormous herds of cattlc arc seen on the Manchurian plains, but these herds belong to a particular tribe, and wide tracts of country separate them. In Shanghai and its vicinity cattle-plague makes its appearance periodically, travelling from dairy to dairy. It is introduced by animals brought here for slaughter, but, I believe, principally by means of feeding materials; in fact, there is no other way than the latter to account for some outbreaks in local dairies. Dairy cattle are fed principally on cotton cake, bran (both made locally), and rice straw, and infection by means of the cotton cake and rice straw is quite obvious. The writer has seen water buffaloes and cattle suffering from the disease working in the local cotton mills. The cakes as they are made are placed just outside the circle round which the animal walks, and the discharges from an infected animal splash over the cakes. The usual situation in which to place a sick animal of any description is under the lee of a straw rick, and hence the source of infection of two of the principal feeding materials in the local dairies is quite apparent. The Chinese admit that the disease is infectious, but they do not admit that it is possible to prevent infection. They are very philosophic over an outbreak, and sum it up by, "b'long very bad joss (luck) have got that deblo (devil) inside." They further believe that one attack usually confers immunity, but they do not recognise that this immunity is absolute, as they do not distinguish this disease from others. They do not make post-1Ilortems or recognise the diagnostic value of pathological changes. Having such a disease to deal with some ten years ago, with, at that time, no effective agent, slaughter being quite out of the question, the only possible solution was effective isolation of the infected. It has been the writer's experience that the period of incubation in naturally infected animals is never longer than seventy-two hours, that invariably the first symptom is a rise of terpperature, and that the beast which shows a rise of temperature does not naturally infect others until after the lapse of twenty-four hours. In an infected dairy the method adopted was to obtain two sites, other than the infected dairy, where cattle could be kept. The thermometer was accepted as being absolute in the detection of the disease. The temperature of all the animals was taken twice daily, and those animals appearing as normal were removed to site NO.2. During the following three days all animals in site No. 2 which showed a rise of temperature were returned to the infected dairy, and after the same period the remainder, showing a normal temperature, were removed to site NO.3. Short, sharp rises of temperature occur in cattle from inexplicable reasons, and all those exhibiting such in site No. 3 were returned to site No. 2. If serum or defibrinated blood from an immune animal is not obtainable this method remains the best at one's dispoc:al, but it often breaks down through unauthorised communication between the three sites. \Vhen the outbreak of the disease occurred in S outh Africa the work of the various commissions was very carefully watched; bile, whether glycerinised or not, was at once discarded for the following reasons :-
GENEJ
195
I. No immunity is granted until eight or ten days after inoculation, during which time all the beasts in contact may contract the disease. 2. It possesses no properties of a curative nature, neither does it modify an attack. 3. Fdr some unexplained reason the disease is extremely likely to follow an injection of bile in three or four months, and the disease then arising runs a most virulent course. (Recent local observations have shown that it is possible for glycerinised bile to actually communicate the disease, with its heaviest fatality.) When serum inoculation was introduced in South Africa a quantity was purchased from that country and arrangements immediately made to produce it locally. The preparation of anti-rinderpest serum does not demand the resources of an extensive laboratory, but simply a beast that has recovered from an attack, sterile glassware, and a sufficient quantity of blood from a beast that is suffering from the disease. The method adopted for the production of serum has been as follows : PrejJaration if tile Serum-jJroducing Animal.-An animal is obtained that has recovered from a naturally contracted attack of the disease, or one that has successfully emerged from a simultaneous injection of serum and virulent blood. In the selection of the animal, for obvious reasons, the following conditions should influence one's selection : The result of an examination of the heart and pulse, and the condition, age, and size of the animal, for, of course, a big, strong, young animal wiII withstand successive bleedings much better than a thin, old, poor one. A suitable animal having been obtained, its temperature is taken morning and ev.ening for three days, and at the en,d of that period, if its temperature has remained normal, an injection of 50 cc. of virulent blood is given. (The temperature of all serum or virulent blood-producing animals is taken morning and evening, and blood is not abstracted for serum, or virulent blood is not injected to raise immunity, unless the temperature has remained normal for at least forty-eight hours.) The result of the inoculation of virulent blood is, as far as the clinical symptoms are concerned, by no means constant, but in 90 per cent. of the cases the temperature rises within seventy-two hours and remains above normal from three to ten days. A secondary rise on the twelfth day is very common, but it does not persist after forty,eight hours. (This secondary rise has always been waited for before .abstracting blood for serum, or before giving another injection of virulent blood.) The height of the rise of temperature does not depend on the size of the dose of virulent blood, but, I think, entirely on the degree of susceptibility of the animal injected. Being guided by the temperature, the first inoculation of virulent blood is followed by an injection of 100 cc. of the same material, then by 500 cc., followed by 1000 cc. When the temperature has subsided to normal, after the last injection, blood is then abstracted for serum. This abstraction is repeated twice more. After the third abstraction -of blood the animal receives, in one injection, a dose of 2000 cc. of
(;ENb~RAL
ARTICLES.
virulent blood, again followed by three abstractions. This second series is followed by an injection of 3000 cc. of virulent blood, alld again three abstractions. 5000 cc. of virulent blood may be injected into an immune animal without any ill effect, but successi\'e and increasing doses of virulent blood, it is claimed, strengthen the protective qualities of the serum obtained. Serum from some individual beasts is undoubtedly stronger than that obtained from others, and for this reason it is advisable to mix all serums obtained on the same date. To ascertain the strength of a serum from any given beast, or to standardise serum, needs the resources of an extensive experimental station, and this is beyond the usual facilities of a practitioner. Unless subsidised, experimental work is practically impossible, and the attempt to produce methods that would enable one to deal with the disease without the standardisation of the serum has always been kept in view. Unless stated otherwise, the results of inoculations, as given later, are results obtained without any attempt at standardisation of the serum. Collection, PreparaHon, and Storage of Serum.- The usual method is to throw the animal, dissect and expose the jugular vein, pass the finger underneath it, insert a small canula, and convey the blood into flasks by means of india-rubber tubing. This procedure takes a considerable time; struggling on the part of the animal is liable to displace the canula, the vein thickens at the seat of operation, and the flow of blood is often irregular and slow, owin~ to the mouth of the canula being blocked by a valve. These are small objections, easier to overcome in theory than in practice. The method recommended is to drive three poles firmly into the ground at a distance of 2 feet from each other. Place the animal to be bled alongside these poles, with the head turned round the erid pole, shave and disinfect the skin over the jugular groove, distend the vein by means of a cord below the site of incision, and make one bold incision through skin, connective tissue, and wall of vein by an ordinary bleeding fleam. The incision can hardly be too bold with a fleam, and, if bold enough, the blood flows in a strong steady stream into a big glass funnel, which directs it to the collecting flask To arrest the flow of blood it is usually sufficient to seize the edges of the wound, cleanse thoroughly, remove the cord, and allow the animal to straighten its neck. Should there be any h~morrhage after the animal has been allowed to straighten its neck, a couple of stitches is all that is necessary. This method of abstracting blood is quickly performed; it renders throwing the animal unnecessary, and it keeps all instruments, glassware, etc .. away from the ground. The first incision should be made as close to the head as possible, and subsequent incisions close to the previous one, following the jugular towards the heart. From an animal of 800 Ibs. or over ill weight, 4000 cc. of blood is withdrawn, and from an animal of 500 Ibs., 2000 cc. Provided the serum-producing animal is liberally fed, the repeated abstractions of blood have little effect upon its condition. Preparation of tlte Serttm.-Long cylindrical serum tubes, fitted with glass caps and holding about 500 cc. each, are the most convenient receptacles to receive the blood in, but they are not necessary. Any glass bottle or jar will answer the purpose, provided it can be thoroughly sterilised. The blood is allowed to stand for twelve hours
GEN ER /\L ARTICLES.
197
in a cool place (in tropical countries an ice box is advisable), after which period the serum is drawn off by means of a sterile pipette into sterile bottles, and ~ per cent. ac. carbo!. pur. is added. The acid causes a precipitate of albumen, but this precipitate does not affect the serum or plug the needles when injecting. The bottles in which the serum is received are then corked with corks that have been boiled for half an hour on three successive days; the bottle necks are wiped dry and dipped in hot sealing wax (or ordinary paraffin dur.). Serum stored in this way will keep for a considerable period. It was found that South African serum bearing dates of preparation five years previously had not lost ih -cfficacy, although it had been subjected to temperatures varying from 50° to I I 5° F. Virulent Blood and its Collectioll.-As a result of many observations and experiments the writer has drawn the following deductions. I t is admitted that in some instances these deductions are merely surmises, but the results of inoculations detailed later seem to justify them. I. The degree of virulence of infective blood varies, but ICC. (the smallest practical working dose) will confer a fatal form of the disease as readily as 100 cc. 2 . The degree of virulence does not depend upon the stage of the disease in which the animal is when the blood is taken, but blood taken from an animal suffering from the sequela! of the disease may not be virulent. 3. Blood appears to possess a more consistently high virulence on the third day of fever following infection. 4. Blood after abstraction retains its virulence for seventy-two hours (possibly longer), and there appears to be no gradual decline of the virulence, or, if there is such a decline, it is not apparent when the blood is injected into a susceptible animal. Accepting the above as being correct, the practice adopted for obtaining virulent blood has been to obtain two animals and inoculate them with virulent blood. (In this country, where the disease is indigenous, it is always possible that a single animal selected for inoculation may prove to be immune through having had the disease previously, and then one's series of virulent blood is lost. To prevent this two animals are inoculated.) vVithin seventy-two hours of the inoculation, and usually within forty-eight hours, the animal's temperature makes a sudden rise, and remains above normal until the sudden drop, which indicates death, appears. The highest point to which the temperature rises is usually on the third day after the first rise of temperature, and it is this period which has been selected for the abstraction of virulent blood. The animal is thrown, the carotid artery exposed, severed, and a bent glass tube carries the blood to the collecting flasks. (5 per cent. of a 5 per cent. solution of cit. of potassium is added to the blood to prevent coagulation.) The carotid artery is recommended in preference to the jugular vein, as invariably more blood is obtained, and the jugular flow is often irregular and slow. Further, accepting deduction No 2, with the possibilities that this opens up, one naturally wishes to obtain a certain standard of virulence, and, therefore, the actual infective blood as it is in the body should be obtained before any physiological
GKNEI
changes can take place. A post-mortem on the animal that has supplied the virulent blood should always be held, and the blood should be examined microscopically. Well-marked lesions must not be expected, and the absence of lesions distinguishing other diseases is of great importance. The Injection of Vimlent Blood.-It is injected subcutaneously. It has been injected intravenously, but the latter method has no advantage over, but rather minor disadvantages against, that described below. There is no difficulty in injecting a small quantity, say 100 cc., but when larger quantities have to be injected there are three points that are liable to cause trouble : I. Disengaging the syringe from the needle, refilling the syringe, replacement of the syringe, and movement of the animal, are all very likely to lead to contamination of the blood with extraneous substances, thereby causing abscesses at the seat of inoculation. (When contamination has occurred, usually the blood is not absorbed but forms large putrid abscesses.) 2. It is very easy to use too much force when injecting blood, in which case connective tissue is broken down and the blood is very slowly absorbed. 3. It takes a considerable time to inoculate a large quantity, say 2000 cc. The method recommended is to place the animal to be injected within a "crush," and fasten it with the head halter only. The bottles containing the blood to be injected are placed in a box, which is suspended 6 feet from the ground and immediately over the animal's back. An india-rubber tube carries the bl ood from the bottle to the hypodermic needle. It will be found that the force of gravity alone is quite sufficient to drive the blood into the tissues, but the force is not sufficient to break the latter down. By this method the blood appears to be more readily absorbed; it takes a very short time to inject a large quantity, and the injected blood from the time it leaves the artery of the animal from which it was abstracted touches nothin g that can not be made sterile. The most convenient sea ts for the injection are the middle of the neck , either side of the scapular spine, R inches above the olecranon, and anywhere over the ribs. \Vhen a large quantity has to be injected all these sites should be visited. Slight pressure immediately over the puncture will immediately arrest any exudation of the injected material. In the majority of cases the injected animal's temperature rises within six to eight hours after the injection, which rise ~ubsides within twelve hours. \Vithin the next seventv-two hours the temperature again rises, and it remains elevateu fo~ variable periods, but neve r l onger than eleven days. After the temperature has fallen to normal fifty-two hours should elapse before a bstracting blood, as slight secondary ri ses for about twenty-four hours are liable to occur. Steriiisation of Flasks, Hottit's, and Jllstru lllents.- The best and most effectual method is by means of dry heat. An ordinary sheet iron box with a false botto m can be made by any local coppersmith. A hole is made in the top of the box for the reception of a bored cork carrying a centi g rad e thermometer. Around the top and sides
GENERAL ARTlCLl<.S.
199
of the box two thicknesses of a medium-weight horse blanket are sewn, and an ordinary gas flame water boiler supplies the heat. Flasks and bottles, after having their necks plugged with cottonwool, are placed in the box, and the temperature is raised and maintained at 1700 C. for one hour. If serum preparation is to be carried out on a large scale, and serum tubes are to be used, it is scarcely practical to sterilise them in this way, and the following method may be substituted. Thoroughly wash the tubes and fill to the brim with a 5 per cent. solution ac. carbo!., which solution is replaced by a 2! per cent. solution twenti·four hours before use. The latter solution is not removed until immediately before receiving the blood. Syringes of a capacity of not less than 100 cc. should be obtained, and such syringes should be easily taken to pieces and have interchangeable parts. Syringes, needle'>, and metal instruments are boiled, and pipettes, india-rubber tubing, etc., are stored in a 5 per cent. solution of ac. carbo!. When using india-rubber tubing, syringes, etc., for virulent blood they are well washed in boiled water to remove all traces of the carbolic solution. Administration of SerU1Jl.- The site selected for the injection of serum is about 4 inches behind and above the olecranon, and this selection is made because here the skin is thin, causing a saving in the breakage of needles. The hair is clipped off, and the skin washed and douched with a 1/1000 solution of perchloride of mercury. This solution dulls the edges of the needles, but the cheapness and efficacy of the solution more than balance the lit.tle extra trouble in sharpening the needles. To prevent contamination of the serum, the syringe is filled by means of a bent glass tube which, together with a small air tube, runs through a bored cork placed in the neck of the bottle containing the serum. The bent glass tube carries a few inches of rubber tubing, on which is placed a stopcock, and in the end of the rubber tubing is inserted the mouth of a broken needle. In 95 per cent. of injections no reaction, either temperature or local, follows, and the serum is very rapidly absorbed. To describe the method recommended for using the serum on an infected herd it will be well to sketch the typical and almost constant conditions found when called in. One is told that an animal has died, and one or more contact animals are exhibiting diarrhcea and other symptoms. A post-mortem is at once made, but the lesions shown vary enormously, and almost invariably the first beast that dies does not show anything approaching the extensive lesions found in the beasts that subsequently succumb. There is often nothing to observe beyond a little inflammation of the fourth stomach. This is apt to make one feel guarded in making a diagnosis, but it is usually found that the condition of the remaining in-contact beasts leaves no room for doubt. An examination of these in-contact animals is made, and their temperature taken. The animals may then be divided into the following classes:Class A.-Refuse all food, fetid gaseous diarrhcea or dysentery, recumbent head and ears drooped, coat staring, watery discharge from eyes and nose (mucoid discharge uncommon in China), acceler-
200
GENERAL ARTICLES.
ated breathing, grunting, in great pain, temperature from 103° F. to sub-normal, pulse thin, weak, and wiry. Class B.~Refuse all food, diarrhcea or dysentery has just commenced, abnormal thirst, respirations accelerated, pulse strong and hard, temperature 104° to 107° F. Class C.-Animals with half their normal appetite, high temperature; otherwise normal. Class D.-Full appetite, no symptoms beyond a high temperature. Class E.-No symptoms and temperature normal. The above simply represents some of the clinical symptoms of the disease and its gradations, but is thus expressed to give the results of injections of serum. Classes A. and B.-Injections of serum in any quantity, either intravenously or hypodermically, will have no effect. If it is thought necessary that an attempt should be made, 300 cc. of serum may be injected into the jugular and repeated in twelve hours, but the case is practically hopeless. Class C.-Should receive 200 cc. of serum intravenously, followed by 100 cc. subcutaneously in twenty-four hours if the animal does not appear worse. These animals will exhihit other symptoms; they require careful nursing and stimulants, and recoveries are in proportion to the attention they receive. About 20 per cent. of recoveries may be hoped for. Class D.-Should receive 100 cc. of serum subcutaneously, which dose is repeated in twenty-four hours. About half of the animals in this class will exhibit other symptoms, the remainder showing no symptoms beyond the high temperature. About 50 per cent. of recoveries may be looked for. Class E.-I t is impossible to state if these animals are infected or not, as they may be in the incubation period. The temperature of the animals that are in this incubation period will rise within fortyeight hours. The method recommended is to give all animals in this class 50 cc. of serum, and to those that show a rise of temperature within the forty-eight hours before referred to give as soon as possible 100 cc., and follow it with another 100 cc. in twenty-four hours. Those that do not show this rise of temperature have not contracted the disease, and the 50 cc. of serum will confer absolute immunity upon them for nine days following the injection. If another dose of serum be given the immunity is renewed. but I am not in a position to state for how long, nor can I offer any opinion as to the effect of a third dose of serum. If, on the other hand, this second dose of serum be not given. and the animals are still exposed to infection, the disease is contracted, usually any time between the ninth and fifteenth day following the first inoculation. If, immediately on the rise of temperature following this naturally contracted attack, another dose of 50 cc. be given, the temperature will run the typical course of the disease, but no other symptoms are exhibited; in fact, it would be impossible to state that the animals were infected were it not for the evidence of the thermometer. Following the above lines in this class,90 per cent. of the animals will be saved. It is curious to note that if a milking cow has not received a dose of the serum the milk is totally arrested within twelve hours of the rise of temperature, whereas if the animal receives a dose of serum and then becomes naturally infected on
GENERAL ART1CLES.
201
the ninth to tenth day, with the usual temperature reaction, the milk is not arrested. Further, those animals that go through a mild attack, which is sufficient to arrest the milk supply, \Viii, if this attack does not last longer than ten days, return to their normal yield of milk. It is believed that those animals exhibiting a temperature reaction are rendered immune for life. In one experimental case an injection of 50 cc. of virulent blood, given nineteen months after, failed to set up the disease; it did not even cause a temperature reaction. The defibrinated blood of these beasts may, in cases of emergency and where there is no serum to be obtained, be successfully employed in arresting an outbreak, provided it is used in doses of not less than zoo cc.
I'"
~~i
Dltiry No.
Owner.
I'~~ ~i§ ~ 0
I .~.:;~ Nlt",uerl ~';l~ of I "t!"
11 ",~;;
II ~ ~
Cows.
,
Deaths...
s.;o De
%)
'1l';:j ;;; g ",.~~~
Percentltye.
Re",,,,'hs.
I
-----1---' ~~.~ --:~~., --,-----------w.
s·1
1
R.
2
R. W. S.
3 4
5
~
",,-<
21
1
1
15
3
24
I
II\)
Ii
I Two control calves left uninocnlated: both died.
--
-
1
17
o
o
H
o i , -I
A. U.
24
()
()
18
2
-
-
;\lr8 F.
23
3
1
4
0
-
-
R. W.
s.
I
i
1
6
R. W, S.
22
7
J. C, F.
3
II
D.W.C.
4
4
4
!l
R. E. T,
2
2
2
10
A. W.B.
2
I)
0
1
11
HongKong Dairy Farm
H
1
1
2
0
-
i
0
7
1
-
-
1
2
0
---
-
-
-
-
-
-
-
-
-
0
-
-
0
-
-
I
- - - - - - - - - - - - - - - - - - -I - - - - - 151 18 17 I lJ4 6 I n'24 I
The above table shows the result of 151 inoculations in eleven different dairies. In dairy No. I certain experiences had to be gained, hence the comparatively heavy loss amongst those that showed clinical symptoms subsequent to inoculation. These results were obtained between five and six years ago, and many other outbreaks have been treated in the same manner since that time, all of which confirm the earlier results. Simultaneous blOcltlation.-Serum gives but a passive immunity, which is of very short duration, and although by its means animals may be successfully carried through a naturally contracted attack, thereby conferring an active immunity, the method of infection is unsatisfactory, inasmuch as the disease is not under one's control. Animals mayor may not become infected. It is not practical when
2C2
GENERAL ARTICLES.
dealing with a large number of animals, and for other obvious reasons. Simultaneous inoculation (a dose of serum and a dose of virulent blood, given at the ~ame time on opposite sides of the body) has been tried by many workers, and I believe discarded by all. My initial experiments were more than satisfactory, and were confirmed by subsequent experiments. The results when put into practice worked out as follows : -
~
Dose
Number
Dose
[«ted.
Sen"".
1;;3
50 cc.
10 cc.
3
10
50 cc.
10 cc.
No second inoculation testing serum
8
100
liO cc.
10 cc.
4 Two deaths
Three deaths
4
-1
188
:if! cc.
10 cc.
88 Eleven deaths
28 Four deaths
.j
35
iiO cc.
10 cc.
Inoc'n-
I
of
of
Death,.
Virulent
Conclusion Drau'n.
Blood.
Ages Three weeks to two years
R
18 Two deaths
0
Reaction insufficient.
0
Reaction insufficient.
70 Sixteen death.
21
Reaction strong.
too
0
17
Reaction strong.
too
Remarks.
0
Reaction insult:cient.
21
15
3
One of these has been proved immune to the disease by a hypodermic injection of virulent hlood five years after, and many have withstood natural infection.
()
6
:iO cc.
10 cc.
Followed hy 50 cc. sernm two days after.
0
Reaction severe.
too
'j
t)
50 cc.
Followed hy 50 cc. serum and 10 cc. virulent blood "ix days after.
0
Reaction severe.
too
35
50 cc.
10 cc.
Followed hy almost daily doses of Eolerum in 50 to 100 cc. doses, accoruing to severity of reaction.
17
Reaction severe.
too
!I
;)t)
,iO cc.
10 cc.
"\s the 8;' lot.
H)
Reaction severe.
too
10
10
Y"adous
10 cc.
Ascertainihg
0
Reactions various.
11 ,
U:;
Various These beasts were inoculated with various doses Of serum and blood in order to confirm Series 10, but the blood was proved non· virulent by the control animals. For certain reasons no further injections were given.
0
13
26
20 cc.
10 cc.
1:3
52
2.1
CC.
10 cc.
In accordance with results obtained in Series 10.
16
14
157
80 cc.
10 cc.
lIIaking an allowance for weight of animals.
38
(j
------
GENERAL ARTICL1cS.
20 3
Virulent blood, and blood described as virulent, was proved to be so by control animals. The serums used were many and various, some prepared in South Africa, some in Manila, and the remainder made locally. Different serums were used in the same series of inoculations, but no difference could be noted in the results obtained. The locally produced serum was always prepared in the manner described. Where the remark "Reaction insufficient" appears, it means that some of the animals showed no rise of temperature or other reaction, and that the remainder gave but a slight reaction. (From subsequent inoculations I have reason to believe that an appreciable reaction may not be necessary to confer a permanent immunity.) The remark" Reaction too severe" indicates that although there may have been no deaths in the series the symptoms were very severe, leaving the animals in a debilitated condition, and causing a good deal of anxiety as to what the result would be. The above series showed that the reactions were not more consistent by reducing the dose of serum, and indicated that a further trial should be given to 50 cc. and bigger doses of serum. . Number S er'!Cs [noruNo. lated.
Dose of
Dose of
SerU'lIl.
Virulent Blood.
I I
De
!
I
4
15
94
50 cc.
10 cc.
16
44
50 cc.
10 cc.
17
25
50 cc.
10 cc.
18
11
50 cc.
10 cc.
19
150
60 cc.
10 cc.
42
20
61
75
CC.
10 cc.
18
21
28
85 cc.
10 ce.
0
22
27
100 cc.
10 cc.
0
Two of these deaths were complicated with piroplasmosis. lOne death complicated with piroplasmosis.
'I
4 2 1
In series Nos. IS, 16, 17, 18, 21, and 22 the reaction and losses were considered satisfactory, but it was difficult to understand the heavy losses in Nos. 19 and 20. In Nos. 15 and 16 piroplasmosis first made its appearance, and three out of the eight that died exhibited hzemoglobinuria. (Piroplasmosis is indigenous in the country, but apparently does not assume a virulent form, probably because immunity is acquired during the first year of life.) The dose of 85 and 100 cc. was not carried further, as the reactions were practically nil, and it is hardly practicable to use such a large quantity of serum on a large number of animals. Up to this point the dose of 10 cc. of virulent blood had been accepted as suitable, as a result of the initial experiments. I further believed that it was immaterial whether I cc. or 100 cc. was used as the infective dose, and did not think it practicable to lise in the field a smaller dose than ICC. In case the dose of virulent blood was incorrect, the following
GENERAL ARTICLES.
inoculations were made, a dose of serum being given the animal's weight : &";es No.
Nttrnberof Anirnal., Inoculated.
Dose of SerurI!.
I
Dose of Virulent Blood.
In
proportion to
De'tfh.~.
I I
-~---------I------
2:3
2
I
2" cc.
ao ce. 60
I
1 cc.
1
1 cc.
13
1 cc.
1
40 ce.
1 cc.
34 I)
3:> ce.
23 2()
i
27
:3
45 ce.
1 cc.
28
aU
flO ce.
1 cc.
This series being most unsatisfactory, it was then decided to ignore the weight of the animals and inject bigger doses of serum, and also serum and virulent blood given on different dates.
---------------.----------------------------------------------Series \
I
. o.
Number of Animals l npc1llnted.
2U
117
GO cc. serum and 1 cc. virulent blood
fi7
:30
209
7:3 cc. serum and 1 cc. virulent blood
7G
:31
78
100 ce. serum and 1 cc. virulent bloot!
34
32
8
50 cc. serum, followed by 1 cc. virulent hlood two days
4
:33
2
100 cc. serum, followed by 1 cc. virulent blood three days
1
34
24
:3fl
5
:3t;
:38
Inoculatcd with.
'I
'
Deaths .
----J-------.-------~
:37
Ii
38
94
39
;~3
40
7
after the serum
after the serum 100 cc. serum, followed by 1 cc. virulent blood four days after the serum 2.> cc. serum, followed in two days by 75 ce. serum and 1 cc. virulent blood 25 cc. serum, followed in three days hy 75 ce. serum and 1 cc. virulent blood 2.'; cc. serum, followed in four days hy 75 cc. serum al1l1 1 cc. virulent blood 50 cc. serum, followed in two days by 50 cc. serum and 1 cc. virulent blood 30 cc. serum, followed in three days by 75 cc. serum anrl 1 ce. virulent blood 50 cc. serum, followed in four days by ,,0 ce. serum and 1 cc. virulent blood
11 3
I" 4 38
7 Ii
The majority of the above animals were required for export; they were going to a country infected with cattle-plague, and it was desired to immunise against the disease before shipment. With boats waiting for their transportation, it was not possible to make as many experiments as one would have wished; hence, often a fresh series had to be inoculated before the results of the last series could be obtained. Further, having once started, it was, for certain reasons, impossible to discontinue, in spite of the heavy losses. The simultaneous inoculation being a financial failure, it was discarded, and an injection of serum alone used. This injection of
GENERAL ARTICLES.
2°5.
!oerum alone was used on somewhere about I 1,000 head of cattle, with the most satisfactory results. On the face of it, the latter statement appears to be of little value, but it means a great deal when one considers that ill this part of China wherever one gathers together twenty or thirty head of cattle, cattle-plague will certainly break out amongst them. Cattle are brought to the sheds in an infected condition, and the thermometer will not distinguish a beast in the incubation period. Given healthy beasts in the first instance, their very food may infect them, and, indigenous as the disease is, contagion assails them from all sides. Again, the buying and storage sheds were badly infected, yet the serum conferred an immunity on those not purchased in the incubation period, and practically all those purchased in this incubation period recovered with further doses of serum. The above is mentioned merely to substantiate the writer's opinion that the serum and its preparation does not account for the failures in simultaneous inoculation, and that therefore one must turn the attention to the virulent blood. The inferences drawn from the results obtained were as follows : Serulll.
The protective activity of serums, as obtained from different serum-producing animals, varies very little from a practical point of I.
VlelV.
2. To ascertain the value of each serum before using it would need the maintenance and resources of a large experimental station. If the first deduction is correct it is not necessary to ascertain the value of serums, and if it is not correct serum is beyond the' scope of practical utility to the average practitioner, unless he is able to ,?btain serum from an experimental station.
Virulent Blood. I. Blood taken from an animal at any stage of the disease (provided serum has not been given) will convey the disease in a fata 1 for111. 2. Though all infective bloods are capable of giving the disease in a fatal form, yet some of these bloods will not convey fatal infection if given in conjunction with serum. In other words, serum is able to nullify the effects of the causal organisms or their products if the former are in a certain condition. 3. Therefore the degree of virulence of blood as taken from an infected animal must vary in its intensity. A.s it did not seem possible to ascertain the degree of virulence of the blood, simultaneous inoculation was discarded, until my attention was drawn to a report by Professor Arloing. l I n this article Professor Arloing claims that it is possible to attenuate the virulent blood to such a degree as to make it innocuous, whilst retaining sufficient virulence to confer some immunity. Further, that by means of repeated dnses of bloods of increasing virulence (1es~ attenuation) it is po'ssible to confer an active immunity. He found that-Defibrinated virulent blood heated to 50° C. for thirty minutes gives the disease in I cc. doses, but not in t cc. doses (Blood I). 1
"Bulletin de la Soc. des Sciences Yet. de Lyon," .Tanuary and Fehruary 1(IOli.
206
GICNICRAL ARTICLES.
Defibrinated virulent blood heated to 50° C. for thirty-two minutes gives the disease only in doses of I cc. (Blood 2). Defibrinated virulent blood heated to 50° C. for thirty-five minutes gives the disease in a benign form in 2 cc. doses (Blood 3). Accepting the above, it was decided to make a few experiments, not with the object of conferring immunity by means of the blood alone but by using the latter in conjunction with serum. Believing that the virulence of bloods varies, and that the highest point of virulence is from the second to the fifth day of fever following artificial infection, I decided to take all virulent blood during these days and attenuate it according to Professor Adoing's method. Animals Nos. I and 2 were so situated as to prevent natural infection by any means, including their food. It will be noted that no serum was given to these animals, as I wished to ascertain whether it was possible to attenuate the virulent blood, and, if so, whether these injections of attenuated virulent blood would confer on the animals an immunity sufficient to enable them to withstand a further injection of unattenuated virulent blood. The deductions drawn from Series A. (p. 207) were:I. That no appreciable immunity was granted by either of the first two inoculations in Nos. I and 2. 2. That Blood 2 in doses up to 4 cc. does not confer sufficient immunity to enable the animal to withstand a dose of virulent blood. 3. That Blood I, even up to 10 cc. doses, does not confer sufficient immunity to enable the animal to withstand a dose of virulent blood. (See secol)d inoculations in Nos. 10, II, 14, 15, and 16.) 4. That Blood I, in doses over 4 cc. given in conjunction with serum, possibly confers sufficient immunity to withstand a dose of virulent blood. After the above results, there were many points that needed further investigation, and certain doses of the attenuated blood should have been definitely fixed, but unless one is working with experimental cattle it is not possible to do exactly what one wishes, and one has to be content with the best possible under the circumstances. The best that could be done was to see if deduction NO.4 was correct. At the wish of the owner simultaneous inoculation with serum and unattenuated virulent blood was also effected, and the latter was useful for comparison. From the inoculations in Series B. (p. 208) it appeared that ;I. The larger doses of Blood I moderated the reaction to unattenuated virulent blood more than the smaller doses. 2. That this reaction to unattenuated virulent blood might be still further lessened by a larger dose of Blood I or a les!:> attenuation of the virulent blood. In other words, obtain if possible a more marked reaction to the first inoculation. Before making any alterations in the degree of attenuation or dosage of the attenuated virulent blood, it was decided to make further inoculations with 10 cc. of Blood I. The inoculations with the unattenuated virulent blood were given at the wish of the owner.
20 7
GENERAL ARTICLES.
S eries .d . .
.~" "1
I
!
1-
FHI ~T
Inocu· lated wtth.
'C-
~
IXOCGLATIOX.
Type of Re(Mtion and Remarks.
--
-~~-
SECON]) I NOCULATION.
bwculatcd with.
1'ypc of Reaction and R emarks.
THIlIIJ
IXOCULATl(lX.
Inoculated 1vith.
Type of Reuction and Re,/ia1·ks .
1 cc. virulent hlood 1 cc. virulent hlood
Usual symptoms, followed by death Usual syml'toms, followetl by dea th Temperature reaction only
Conclu:-;ion Drawn .
--~--- -
1
:I cc.
None
1 cc.
None
2
2 ce. B. 3
None
1 cc.
None
1 cc.
None
2 ce.
None
None
4 cc. B.l
None
2 cc. virulent blood
12 ' 1 cc. R2 50 cc. serum
None
2 cc. B.2
None
2 ce. virulent blood
1J
None
4 ce.
None
2 cc. virulent blood
Los. of appetite and diarrhcea j no t emperature. Possibly not a rinderpest reaction
10 cc.
10
1l.3
!
B.1
50 cc.
B.1 B.2 B. 1
serum
11
2 ce.
R1
50 cc.
serum
2 cc.
B.2
50 cc. serum (Portion of serum wasted) 14
7 cc. B. I 50 cc.
serum
B.2
B.l
Temperature only
15
6 cc. B.l 50 cc. serum
None
10 cc.
None
Hi
:3 cc.
None
10 cc.
No temperature, but latter irregular. No appetite. D i a r r 00h a. Dysentery No reaction
B.1
,30 cc. serum
B.l
B.l
2 ce.
virulent blood
Satisfactory.
Typical attack of dise !ts~ . Reaction far too ~ev e re. Death Reaction very severe, followed by
Not satisfactory.
U,ual syml'toms, followetl by death
Not sati , factory .
Not sat isfactory.
2 cc. Temp e rature Doubtful. virulent reaction antl blood con s id e rable "ystemic disturbance. No other sylnpI toms I Typical 2 cc. t em- Not satisvirulent peratur~ r eo factory. action blood and other It"llal reaction t oo
2 ce. virulent blood
bevere
Had
not
rt··
covered from previollS re-
""ot ,atisf,~ctOl'Y.
action. Death
17
4 cc. B.I 50 cc. serum
None
2 ceo virulent blood
18
5 cc. B.I 50 cc.
None
2 cc. virulent blood
T e mp e ratur e only; excellent reaction
Hel,t]:'.·
X cc.
None
2 cc. "irulent blood
No r eaction
DOllhtful.
serum
19
, B. l
50 cc. serum - -- _.-
Doubtful.
factory .
208
GENERAL ARTI CLE S.
Series B. FIRST INOCULA'fION
- - - - - - , - - - -- - --
I noculatcd with.
T ./fPC of Reactim
and &11.,wk8.
SECOND I NOCULATION.
Conclusion D rawn.
1 -------- -- ------ - - --
T ype of Reaction und &111«1·1.:s.
Inoculated 1!lith.
20
5 cc. virulent blood 30 cc. serum
second Temperature only. No R eaction sat isinoculation fact ory.
21
5 cc. virulent blood :)0 cc. serum
Temperat ure an
second No inoculation
Not satisfactory.
22
,j cc. vir ulent hlood .')0 cc. serum
Temperature, loss of aprotite, and diarr rea. Too
No second inoculation
Not satisfactory.
No. 22
Satisfactory.
severe.
As No. 22
Not satisfactory.
Z;{
A~
2-1
-1 cc. B , 1 .')0 cc. serum
2 cc. virulent blood
,,-
Temperature on ly '\ severe, extend· iog over nine I days
~, l
6 cc. B. 1
2 cc. virulent blood
Temperature over seven days; partial loss of appetite
21i
l> ce. B. 1
50 cc. seru m
2 ce. virulent hlood
Temperature over five days; slight loss of appetite
:li
10 cc. 11. 1 :)() ce. serum
:3 cc. virulent hlood
T emperat ure over six days; d ial'rhrea one
2t!
10 cc. B . 1 50 ce. serum
2 cc. vir ulent hlood
Temperature over four days; diar r hrea four days
!l9
10 cc. B. 1 30 cc. serum
2 cc. virulent bloo<1
Temperature over three ,lays only
30"
10 cc. v irulen t Temperature seven 2 ce, virulent blood. blood days 50 cc. serum
.)0 ce. serum
* Inoculate<1 with virulent blood as no B . 1 avai~ahl e . fourth day of fever, t herefore con clusion of no value.
I I
I I Symptoms were
I
not severe enough t o cause any anxiety. Mayall be classed as satisfactory.
Received another
20 9
GENERAL ARTICLES.
r:. I
.£:'"
~eIRST
INOOCLATION.
"
SEOOND INOOULATION. --
~
'2
inocul«ted with.
~
-,~~-----
Type of Renetion and Remarks. ~~-----~-
Inoculated ~vith.
Type of Reaction and Remarks.
Conclusion Drawn.
-----~- ~~----~~- ~~--~----
31
10 cc. B. 1 50 cc. serum
-
2 cc. virulent blood
Temperature over three days only
Satisfactory.
32
10 cc. B. 1 50 ce, serum
-
2 cc. virulent blood
None
Doubtful.
2 cc. virulent blood
No temperature reaction or further symptoms. Died ou six th day. Post-mortem. Rinderpest
33\ 10 cc. B. 1 50 cc. serum
I
Uncertain. Tern· perature irregular; diarrhcea two days
I
-
10 cc. virulent Too severe. hlood Death.
-
-
Not satisfactory_
35
10 cc. virulent Very severe. blood iJO cc. serum
-
-
Not satisfactory_
3(;
10 cc. virulent Temperature over days. blood eight Too sever~. 50 cc. serUln
-
-
Not satisfactory_
37
10 ce. virulent Too severe. blood Death. 50 cc. serum
--
-.
Not satisfactory.
Temperature only six days
34
50 cc. serum
10 cc. B. 1
Uncertain. Temperature irregular
2 cc. virulent blood
3!l
10 cc. B. 1 50 cc. serum
None.
2 cc. virulent Temperature only. Not satisfactory. blood Death.
40
10 cc. B. 1 50 cc. serum
-
2 cc. virulent blood
Temperature and other symptoms. Death.
Not satisfactory.
10 ee. B. 1 50 ce. serum
-
2 cc. virulent blood
Temperature only nine days
Not satisfactory.
42
10 ce. B. 1 50 ee. serum
-
2 ec. virulent blood
Temperature only seven days
Not satisfactory.
43
10 ee. B. 1 50 ce. serum
Temperature only
2 ce. virulent blood
Temperature con- Doubtful. tinued from first inoculation for seven days
44
10 cc. B. 1 50 cc. serum
45
10 ce. B. 1 50 ee. serum
Temperature ir- 2 ce. virulent regular. Doubtblood ful 2 ee. virulent blood
38
41
50 cc. serum
I
Satisfactory.
Temperature only six days
Satisfactory.
Temperature only six days
Satisfactory.
The results of this series were not satisfactory. It seemed that sufficient immunity had not been conferred by the first inoculation. It was decided to attempt to obtain more reaction to the first o
GENERAL ARTICLES.
210
inoculation by (I) less attenuation of the virulent blood (Blood 4 and Blood 5), and (2) a bigger dose of Blood I.
Series D.
]
FIRST INOCULATION.
'"
~
'c>
~
Inoculated witk.
Tupe of Reaction and Remarks.
SECO~])
I
Inoculated witk.
ISOCULATIO:-I.
Conclusion Drawn.
Type of Reu,ction a1ul Remarks.
I - - - '-- - - - - - - - - - - - - - ----,-
i 2 ec. virulent
..Iii
nee.B.5 50 cc. serum
None
47
5ce.B.5 50 cC. serum
Temperature irregular only. Doubtful
48
10 cC. B. 5 50 cc. serum
Temperature only 12 cc. virulent five days blood
49
10 cC. B. 5 50 cc. serum
Doubtful. Tem· perature irregular
50
5cc.B.4 50 ee. serum
51
5ee.B.4 50 ee. serum
blood
2 co. virulent blood
Temperature only four day"
Satisfactory.
Temperature only seven days
Satisfactory.
None
Inoculated with a temperature of Satis· 103'4°. factory.
2 cc. virulent blood
Temperature only six days
Inoculated with a temperature of 103'6°. Satis· factory.
None
2 ee. virulent blood
Temperature only six days
Satisfactory.
None
2 ce. virulent blood
Temperature only eight days, and diarrhrna
Too severe.
I
i
52
10 cc. B. 4 50 ce. serum
Nonel
2 ce. virulent blood
None
53
10 ce. B. 4 50 ec. serum
None
2 ee. virulent blood
Temperat\lre four days
Satisfactory.
54
15 ee. B. 1 50 ec. serum
Temperature only six days
2 ce. virulent blood
None
Satisfactory.
55
15 cC. B. 1 50 ce. serum
Temperature only two days
2 cc. virulent blood
None
Satisfactory.
2 cc. virulent blood
Temperature only three days
Satisfactory.
2 cc. virulen t blood
None
56
20 ee. B. 1 50 cc. serum
57
20 cc. B. 1 50 cC. serum
I
None None
i
i
-
It
was believed this beast had received a simultaneous iniec· tion before, but uncertain.
A
}lost· mortem could not be made.
I I
I
58
20 ce. B. 1 50 cc. serum
A thin, poor beast in bad physical condition. Died on fifth day after inoculation, with no visible symptoms of the disease.
It was then considered that the best results were obtained from the injection of IS cc. of Blood I and that this should be confirmed. Unfortunately, circumstances over which I had no control made a slight alteration in the virulent blood, inasmuch as citrated blood in place of defibrinated blood was used on Nos. 64 to 71, both numbers inclusive.
GE,NERAL AR'llCLES.
2 I I
Series E. :-;~;COND INOCULATION
FIRST INOCULATION.
~~ Inoculated--~ype (If Rwction with. and Rem',rks.
Inoculated with.
'I'
I j
Type of Reaction and Remarks.
--:,-------- ----------I-------i----------------59 I 15 ee. B. 8 Temperature irregu-12 ee, virulent Piroplasmosis. Death. U "ual 50 ee. serum
lar on two days
60
15 ee. B. 8 50 ee. serum
Temperature irregu1ar on four days
2 ee. vinllent blood
Piroplasmosis. Death. symptoms very severe.
Usual
61
15 ee. B. 8 30 ce. serlun
Temperature irregular on four days
2 ee. virulent blood
Piroplasmosis. Death. symptoms very severe,
rsual
62
15 ee. B. 8 ~O ee. serum
Slight rise. Doubtful
2 ee. virulent blood
Death. Piroplasmosis. symptoms. ~ery severe,
rsual
63
15 ee. B. 8 50 ee. serum
Slight rise, thirtysix hours
2 ee. virulent blood
Piroplasmosis. Death. symptoms very severe.
l'sual
()4
15 ee. B. 7 50 ce. serum
None
2 ee. virulent hlood
Piroplasmosis. Death. symptoms very severe.
Usual
65
15 ce. B. 7 50 ee. serum
:None
2 ce. virulent blood
Piroplasmosis. Fever extending over four days. Redwater. Not a severe attack.
66
15 ce. B. 7 50 ee. serum
Temperature irregular on five days
2 ee. virulent hlood
Piroplasmosis. Death. symptoms very severe.
67
Hi ee. B. 7 50 ee. serum
~one
2 ce. virulent bloo(l
Piroplasmosis. very severe.
Usual symptoms Recovery.
15 ee. B. 7 50 ee. serum
Temperature irregu1ar on eleven days
2 ce. virulent hlood
Piroplasmosi". very severe.
rsual symptoms Death.
115 ee. B. 7 , 50 ee. serum
None
2 ce virulent blood
High fever teu days after inoculation of virulent blood, lasting for three days only. No other symptoms. Piroplasms found in the hlood during the fever.
15 ce. B. 7 50 ce. serum
None
2 cc. virulent hlood
Piroplasmosis. very severe.
Usual symptoms Death.
71
J5 ce. B. 7 50 ce. serum
None
2 ce. virulent blood
Piroplasmosis. very severe.
Usual symptoms Recovery.
72
15 ce. B. 7 50 cc. serum
None
2 cc. virulent blood
Piroplasmosis. very severe.
Usual symptoms Recovery.
73
15 cc. B. 6 50 ee. seruin
None
2 ce. virulent hlood
Temperature irregular four days only.
74
15 ce. B. 6 50 ce. serum
None
2 ce. virulent 'blood
Steady rise and decline of temperature extending over six days.
75
15 ee. B. () 50 ce. serum
None
2 ee, virulent blood
Steady rise and decline of temperature extending over ten days,
76
15 ce. 'B. I) 50 ce. seruD).
Temperature days
2 ee, virulent blood
Steady rise and deeline of temperature exten(ling over ten days. -
77
15 ee. B. 6' 50 ee. serum
None
2 ee. virulent blood
Temperature two days. ~eeondl\ry rise Oil tenth day to normal on sixteenth day.
78
15 ce. B. G 50 ce. sernrn
Temperature days
2 ce. virulent hlood
Steacly rise and decline of tempera, ture extending over five days.
68 ,
6!J
,u
-------
hlood
two
six
symptoms very severe.
i
----~--
212
GENERAL ARTlCI.ES.
Piroplasmosis is indigenous in China, and in my experience has never caused any serious loss; it therefore must be assumed that all cattle are immunised naturally when calves. In one or two previous instances the simultaneous inoculation has awakened the latent infection with a fatal issue, but never so seriously as in this instance. Perhaps one or two beasts out of a large number have succumbed to the combination, but from the above series it appears possible that the death roll may be heavy. I am not prepared to say that the virulent blood given did not contain piroplasms, and it would be a bold statement to affirm that blood taken from any beast in China did not contain the organism. These beasts were divided in three different houses :In House I. there were in all twenty-three beasts, of which number eighteen had been the subjects of cattle-plague previously, the disease either having been contracted naturally or given artificially. The remaining five appear in the series above as Nos. 59 to 63. In House I I. there were in all twenty-two head, of which number thirteen had been the subjects of cattle-plague under the same conditions as in House I., leaving nine (Nos. 64 to 72), which we were attempting to immunise. The above beasts' ages were from eighteen months to four years. In House III. there were nine yearlings (previously immunised by simultaneous methods) and six calves (Nos. 73 to 78), all about six weeks old. The virulent blood given in the three houses was exactly the same, and 1000 cc. of the same blood was utilised to further fortify an animal for the ultimate production of serum. On the latter the blood had the usual effect, viz., a rise of temperature and nothing further. The reaction given by the calves (House III.) was nothing but a temperature reaction; the appetite and bowels were unaffected. Piroplasms were found in the blood of those cattle from which films. were taken, including the calves. Fifteen days after the injection of virulent blood one beast out of the eighteen mentioned as being immune in House I. refused its food; its temperature was taken, and cattle-plague immediately suspected. The animal died, and the post-mortem revealed cattleplague. Two days after two more were affected in House I I.; one died (post-mortem, cattle-plague) and the other recovered, recovery being assisted by serum. The infection of these beasts proves that the virulent blood used carried the cattle-plague organism in addition to the piroplasm, and it further indicates that the immunity conferred by a slight attack is not absolute in all animals. I have proved beasts to be immune to a hypodermic injection of virulent blood six years after a simultaneous inoculation, and this is the second case in which occasional beasts have proved themselves to be non-immune some time after a simultaneous inoculation (in this case three and a half years). There can be no doubt that some animals possess more natural immunity to the disease than others, for some animals give no reaction to the simultaneous inoculation, and a subsequent dose of virulent blood fails to infect, yet the same simultaneous injections can convey a fat,al attack to another animal.
GF.N~; ](AL
AR'IICLES.
21
3
I ndigenous as the di sease is in this country, and in view of the absolute and usually lifelong immunity that is conferred by a sharp attack, it is not difficult to believe that a certain degree of immunity may be passed from dam to offspring, and, if this is so, the varying degrees of susceptibility as found in different animals may be accounted for.
PRELIMINARY NOTE ON THE TRANSMISSION OF EAST COAST FEVER TO CATTLE BY INTRAPERITONEAL INOCULATION OF THE SPLEEN OR PORTIONS OF THE SPLEEN OF A SICK ANIMAL.
By Dr K. F. MEYER, Pathologist, Government Veterinary Bacteriological Laboratory, Pretoria. As the result of the investigations of Robert Koch,! A. TheileJ} and others, it was found that East Coast fever could not be transmitted by injections of large or small quantities of blood, even although the infected , blood contained enormous numbers of the characteristic parasite, piroplasma parvum. This is a feature of the disease which serves to distinguish it from Texas fever or common redwater, and although Koch and his assistants also attempted to reproduce the disease by other means, such as the subcutaneous or intrajugular inoculation of spleen pulp and material from lymphatic gland (these materials being selected amongst others for experiment because these organs contain an enormous number of Koch's granules, which they considered to be a stage in the life cycle of the piroplasm), none of their experiments were successful. Theiler's experiments on similar lines also gave negative resuits with regard to transmissibility, and hitherto the only known method of reproducin g the disease has been by the agency of infected ticks. During the study of the genesis and development of Koch's granules I have noticed that the ha:mopoetic organs contain at the commencement of the disease granules or intracellular bodies which differ from those seen in these organs during the later stages. Those granules seen in the incipient stages appear before piroplasms are observed in the blood stream. It was noticed when collecting material for my experiments that the operation for the removal of lymphatic glands, spleen, and portions of the lymphatic glands was accompanied with little or no risk in the case of South African cattle, provided that the usual antiseptic precautions were observed. At the same time it was ascertained that the excision of these organs did not alter the ordinary course of the disease. The general outline of the technique is as follows : 3_ Laparotomy is performed on the near side ; the preparation of the site for the operation is as usual. To minimise the risk of infection, I "Reports on Rhodesian Redwater or African Coast Feyer," Salish1ll'Y, l!lO:3. "The Agri· cultural Journal," Cape of Gooa Hope, Vol. LXXIII., H10:l, and Vol. XXJV., 1904. "Archiv. f. Tierheilkunde," H104. "Deutsche l\Iedizin, IYochenschrift, " 1!l04, p. 140:;, and 1901\, p. 18(j5. 2 "Annual Report of the Government Veterinary Bacteriologist, " 1!l03·04, IH07·0H. "Rho· desian Tick Fever: Report of the S.A.A ..l.S.," Johannesburg, 1!l0,t, " Details will be publishtd in a later report.