ABSTRACTS. 137

and the distribution in the human body of variant strains of tubercle bacilli.

It is noteworthy that attenuated strains of tubercle bacilli were found only in what may be described as the external forms of tuberculosis, i.e., .in cervical gland tuberculosis, in a thigh abscess, and in the skin tuberculOSIS. Of the two forms of tuberculosis affecting the skin which have been examined, lupus has yielded a higher proportion of attenuated strains than scrofulodermia. Since lupus is the most superficial of the various kinds of tuberculosis which have yielded attenuated tubercle bacilli, there is evidently close relationship between attenuation of tubercle bacilli and nearness of the tuberculous lesion to the surface of the body.

Types of I"jection.

Ii ., Atypical. '2.~ " Standard Types.

~ ~

" " ~? "0- "' ..... Age Periods. t; 'tl In " "" ;::§~ O"ltural .. .: .c .: In Virulence . ".~

" .; Oharac- ~'" ~

OJ -s ~ §.:: c

" '" ~ '" teri.tics_ J:q

~ c -~ ".il J:q ~~ Hurnan. Human. Bovine.

------ ------------------

o to 5 years 221 133 76 2 2 3 5 37'55

5 to J 0 " 312 208 81 I 5 7 10 29'45

10 to 16 " J 50 119 17

I

- 6 3 5 14'66

16 and upwards 38 4 342 20 2 8 10 2 6'25 -------1------ ----

Total. 10681 8031 194 5 2 I. 23 22 20'7

1 Including one case, the age of which was not stated.

The total number of cases of human tuberculosis now investigated in this COllntry by identical methods and reported on is 1068, as shown in the above table. (A. Stanley Griffith, Journal of Pathology and Bacteriology, Vol. XXII!., 1920, pp. 129-J52.)

ANTHRAX IN SOUTH AFRICA.

Regulations dealing with Control and Suppression.-Prior to 1910 anthrax was dealt with under the various Colonial :::-.tock Diseases Regulations then in force in the various colonies, now provinces, within the Union. In general, the methods then used in coping with outbreaks were those of short quarantine and movement on to a clean area of the animals amongst which the disease had appeared. When the outbreak occurred in a herd or a flock on a farm, immediate movement on, to a clean portion of the same farm was allowed, and if the animals moved then remained free from the disease, the quarantine was removed after about a week. When cases occurred amongst transport or other animals moving on the road, the animals

K

ABSTRACTS.

were allowed to move a short distance from the place where the disease first appeared, and kept them here for three or four days. If no further cases then occurred the animals were allowed to proceed on their journey.

In the Cape Colony Pasteurian vaccination was also used to some extent, and for some localities was strongly recommended although not insisted upon. In the Transvaal and Orange Free State its use in earlier years was not recommended owing to the then apparently limited incidence of the disease. The Transvaal Stock Disease Regulations, drawn up under Ordinance No. I7 of 1902, provided for the disposal of the carcases of animals dying of anthrax, and directed that these should be burned or buried intact.

In the other colonies, however, none of the stock regulations indicated what measures should be taken for dealing with the carcases of animals dead of anthrax, the matter being left to the discretion of the authorities in whose hands the administration of the general stock regulations was placed.

The existing regulations dealing with the disease are those made under Act No. 14 of 1911, "To consolidate and amend the Laws in force in the Union for the prevention of Disease amongst Stock." In these regulations provision is made that the owner shall cause tbe carcase of any animal that has died, or is suspected of having died of anthrax, and also any infective excreta, litter, or discharges, to be destroyed by burning or burial; and in addition it is laid down that it shall be the duty of the owner or person in charge of any animal which has been in contact with an animal affected with anthrax, to cause or permit such animal to be innoculated at the discretion of the principal veterinary officer. Owing to the difficulty, however, of compelling owners to comply with the regulations providing for the destruc­tion of infected carcases and infective materials, it is upon preventive inoculation that main reliance has come to be placed in dealing with all serious outbreaks. With the increasing prevalence and spread of the disease, the practice of preventive vaccination has therefore been very greatly extended, and up to December 1915 the vaccine exclusively used' was that obtained from the Pasteur Vaccine Laboratory, Paris. The vaccines­so obtained were the usual two types supplied by that laboratory. One of these, the "double-vaccine," consists of two cultures corresponding in degree of attenuation with the Pasteurian first and second vaccines, and is injected with a twelve to eighteen days interval between the weaker first and the stronger second. The other, or "single-vaccine," is one whose virulence lies between that of the usual first and second Pasteurian vaccine, and in its use only one inoculation is necessitated.

Towards the end of 1915, however, the conditions resulting from the war rendered it impossible to depend upon regular supplies from Paris, although the demand for vaccine was increasing in an unprecedented fashion. The rate of increase of demand is illustrated by the following table, which shows the total quantities of anthrax vaccine issued yearly by Government laboratory from March 19II to March 1918:-

Year. 19 II -19 12 19 12-19 I 3 1913- 1 9 1 4 19 1 4-1 9 1 5 19 15-19 16 .19 16-1 9 17 1917-1 9 18

No. of doses z"ssued. 30,100 65,200 99,3 2 5

190,605 399,680 696,85 0 50 9, IIS

ABSTRACTS. 139

On account, therefore, of the rapidly risir,g demand, and also because it was thought futile to meet the position by keeping a reserve supply of material on hand in face of the advice that the material should be used in as fresh a state as possible, the expedient of preparing and issuing vaccines made from the imported attenuated strains was adopted in December 1915. Since then local preparation has been maintained, the author taking over the preparation of this material in April 1916. In July 1916 the issue of the imported vaccine was almost completely discontinued, and the amount of locally prepared material issued between then and July 1918 amounted to n.earlya million doses of single-vaccine. In the ensuing text the latter is referred to as "locally prepared" (L) and the former as "imported" (I). During the period April 1916 to January 1917, owing to dIfficulties encountered in obtaining supplies of suitable bottles and corks, and also because experience up to that time did not markedly contra-indicate its general use, the only vaccine prepared and issued locally was the single. Towards the end of 1916, however, certain post-vaccinal accidents, to be mentioned later, were reported to follow the injection of this material into horses and cattle, ar.d the issue of the double vaccine for general use was therefore reinstituted in 1917. From that time the single vaccine has been issued for the innoculation of cattle only, and then only when specific­ally demanded. In the preparation of the vaccine locally, batches ot about twenty to thirty thousand or more doses are made at the same time. The seed _cultures consist of 36-48 hour agar slant cultures of the attenuated organism, and from these the growth is washed off by means of sterile broth introduced by a pipette. The emulsion thus obtained is then innoculated into a slightly alkaline peptone salt bouillon prepared from beef in the ordinary way, but diluted four times with distilled water. The flasks containing the medium are half filled and plugged with wool through which two fairly narrow glass tubes pass. One of these is relatively short, project ing into the flask only a short distance below the plug, and serves for pipette­inoculation of the flask with the emulsion obtained from the seed cultures. The other longer tube reaches to the bottom of the flask, and is bent outside at an angle of about forty degrees. Its ollter end, more or less at the level of the mouth of the fI'l.sk, is fitted with a rubber tube joined toa glass end-piece, which is drawn out and sealed. In the process of bottling, this end-piece is passed through an inverted glass funnel, the end broken off under the usual conditions of sterility, and the liquid then removed by siphoning. _

After inoculation the flasks are incubated at 37° C. for a minimum period of forty-eight hours. The vaccine from one of the flasks is then bottled and cultures taken for the small animals virulence tests. These cultures are grown in broth similar to that contained in the flasks and injected subcutane­ously when about forty to forty-eight hours old into white mice, guinea-pigs, and rabbits. If this test proves the vaccine to possess a suitable degree of virulence, the remainder of the flasks are then bottled. The bottles of vaccine are then placed in the incubator at 37° C. in order to test the bacterial purity of their contents, and then transferred to cold storage until time of issue. Before dispatch each bottle is individually examined, and any showing an unusual degree of cloudiness -or sediment are rejected. As a control test in purity, agar and broth cultures are also made from sample bottles filled from each flask.

So prepared and controlled the vaccine is then supplied for use, labelled with the date before which it must be used. This date is taken as a month from the time of issue from cold storage in the case of the ., first lymph" of the double vaccine, and up to six weeks in the case of the" second lymph."

ABSTRACTS.

According to present recommendations the use of the" double vaccine" is advised for all classes of stock-in the dose of ! cc. per head at each inoculation for cattle, and of 1- cc. per head for horses, mules, donkeys, sheep, and goats. The dose of the "single" vaccine prepared for the inoculation of cattle only is! cc. for each animal.

In practice vaccination is largely undertaken by stock owners themselves, but it is also carried out extensively by the Government veterinary officers or the inspectors of stock serving under them, especially in those cases where it has to be enforced as a measure of State control. In the instruc­tions issued with the vaccine, its use on clean farms is not advised except in those cases where the local conditions are such as to render it extremely probable that infection may be introduced from sources of infection existing in the immediate neighbourhood. In actual practice, however, its use is only resorted to in the majority of cases when infection has already made its appearance, and then usually only after a number of animals have actually died from anthrax. Even under such conditions a cessation of mortality frequently occurs within a few weeks after the vaccination has been completed. In some instances, it is true, the number of deaths from anthrax increases immediately after vaccination, and it has also been noted that at times mortality continues to occur beyond the period of fourteen days from the time of completion of vaccination-within which immunity is usually accepted as being conferred-even up to the fourth week from this time. This, however, refers more particularly to those cases where the animals vaccinated have been left to graze over the area on which infection was originally acquired. Under such conditions adverse results might be expected--the negative phase following vaccination most probably accounting for the more immediate increase in mortality by favouring the development of infection in those animals which had already acquired it, and the more remote deaths being accounted for by continued exposure to infection before immunity has had time to become established. Whether this be the correct explanation or not, practical experience indicates that the best results from vaccination are to be expected when the animals are removed immediately after inoculation from the infected area to a clean or less-infected one, and there kept for at least a month before return to the former. Considering that beneficial results have been obtained in a large number of cases, there is therefore good reason for advocating the practice of vaccination, even though definite judgment as to its exact value be suspended until more extended e~perience has been acquired, and more complete statistical information it; perhaps available. At the present time one must be mainly guided by the general opinion of veterinarians and others concerned with the application of the method on a large scale in the field. If provisional evidence of this kind be admitted as justifying a conclusion, there is ground for the belief that in the majority of cases vaccination has yielded results of a satisfactory character, and that in general its efficacy has been at least as great as the favourable records from other countries allowed us to expect. But, while the general results may be said to be satisfactory, complaints have been received at times, in some cases concerning accidents apparently resulting from the vaccination, and in others concerning failure to produce the expected immunity. The complaints received, however, have been extremely few in comparison with the number of doses issued, and the author considers it practically certain that, if the losses due to vaccination could be expresse-d statistically, they would sink into insignificance in comparison with the main beneficial results. But although accidents and failures are rare, their importance as a source of dissatisfaction is great

ABSTRACTS. 141

because of the way in which the incidence of loss or inconvenience entailed through them is distributed; an incidence not dispersed in a general way, so as to affect a number of owners in a slight degree, but is usually borne by a few individuals. The vaccine-maker is mainly concerned because the occurrences complained of are not recognised by the users of the vaccine as dependent upon any possible inherent defect in the Pasteurian method itself, but are invariably attributed to faulty preparation of the vaccine supplied. The statistical minority of unfortunate accidents is therefore of considerable importance. The unfavourable aspect of vac­cination which they serve to bring into prominence, and the probabilities underlying their causation, are discussed separately by the author under the headings of: (I) post-vaccination accidents; (2) failures of vaccination to produce immunity.

Post- Vaccination Accidcnts.-That accidents are not more common than they actually are might be remarked upon as a rather surprising fact, in view of the number of known cases in which the vaccine has not been administered in accordance with the instructions supplied for its use, but with varying degrees of disregard of them.

Although maladministration is a side issue and need not be dealt with in discussing post - vaccination accidents proper, the author cites a few reported instances, such as the use of unsterilised syringes or of unclean receptacles into which the vaccine is poured at the time of the operation; the mixing together of "first" and "second" vaccines for injection as a "single" (?) vaccine into animals not previously inoculated; the injection of a dose much larger than that recommended, or of the second vaccine before the first; the removal of some of the vaccine from a bottle and the keeping over night of the remainder for use next day; the once­recorded injection from the nozzle of the syringe into a puncture in the skin made with a nail, because of the loss of the syringe needle; and, finally, an apparently common practice of abstracting some of the material from the bottle by pushing the needle through the cork and keeping the remainrler for use for several days later, when the effects of the first injections have been observed and passed as satisfactory. Curiously enough, however, disaster appears to have seldom followed in the wake of such extreme misuses of the vaccine. The more serious "accidents" have been observed in cases where the injection had been properly carried out, and the character of such sequelre has varied.

In the m ljority of instances the development of swellings on different parts of the body-not necessarily present at or developing from the actual inoculation site-has been observed. In other cases there has been noticed a lameness or stiffness in movement, affecting one or more of the limbs but not as~ociated with swellings. In a small minority of cases mortality has occurred.

By way of illustration, the following records are given in detail :-Farm I.-Vaccine used, single (L); dose, 1 cc.; animals affected, bovines.

Anthrax not previously existent on area where animals were kept or were working. One hundred and thirty-four working oxen inoculated behind the shoulder, allowed to rest for about forty-eight hours after the inoculation, and then again put to usual transport work. From about the seventh day after vaccination cedematous swellings were noted in a large proportion of the animals, and by the ninth day were apparent in practically all members of the troop. These swellings were stated to have been absent at the inoculation site, but present in the lower part of the dewlap and chest, extending in some cases backwards along the lower aspect of the abdomen. to the sheath. In some cases the fore leg on the side on which

ABSTRACTS.

the inoculation was performed was also swollen. In thirty-three animals the swellings developed to such a marked extent as to interfere with movement. After about ten to fourteen days from the time of their first appearance they had again disappeared. During the time they were present the animals fed well, and apart from the associated mechanical interference with movement no other symptoms were noted. Only one of the animals thus affected died, death taking place on the thirteenth day after inoculation.

Farm 2.-0n Farm 2 (a native location) an outbreak of anthrax occurred in December 1916, and it is estimated that about 200 bovines had died before vaccination was carried out in January 1917. In at least the earlier period of the outbreak the conditions were such as might be expected to have produced a widespread dissemination of infection over the grazing area and a relatively heavy infection of some parts of the location. A large number of carcases had been cut up and consumed by native owners, about eighteen of whom themselves contracted the cutaneous form of the disease. In the third week of January 1917 the survivors of the herd, numbering about 6700, were inoculated with single vaccine (L) in the dose of icc. per animal. Deaths from anthrax continued to occur in considerable numbers for several weeks after inoculation, and up to the sixth week about 211 animals wt;re reported to have died. By about the ninth week, however, the mortality, which had been progressively decreasing from the lime of inoculation, ultimately ceased. Of the 6700 cattle inoculated swellings were observed in twenty·two animals, and of these eight died. The earliest time after inoculation at which these swellings were noted was about the ninth or tenth day, although in some cases they did not appear until the third or fourth week; and, while in some instances they disappeared in about seven to ten days, in others they persisted for some weeks. In the majority of cases they were located in the lower portion of the dewlap, the front of the shoulder, and the forearm of the same side of the body as that on which the inoculation was made, but in four animals they were present in the posterior portion of the body, extending to the hind limbs in two. In one of these four individuals the swelling developed in the posterior portion of the lower aspect of the abdominal wall, and thence extended to the upper parts of the inner faces of both thighs. In this case the appearance of swelling was noted three days before death, which occurred twenty-eight days after inoculation. In two others the posterior fourth of the abdominal wall, lower portions of both Ranks, and precrural regions were involved. while in the fourth animal there was redema of the perineal region and also in the upper part of the inner faces of both thighs. These swellings were not painful, and even the animals in which they persisted for some time did not appear otherwise visibly sick, but continued to move about and feed as usual. In six other cattle stiffness and difficulty in movement occurred. In five of these the symptoms appeared about three to four weeks from the time of vaccination, and in the sixth animal in the fifth to sixth week from this time. Once present they persisted for several weeks, except in the case of one animal in which they were noted only three days before death, a month after the inoculation. In three animals stiffness was present in all four limbs; in a fourth in b9th fore limbs; in a fifth in the left fore and both hind limbs. In a sixth, which also showed a swelling of the left fore­arm, first the right fore and later both hind limbs, were affected.

Farm 3.-0n the 19th January 19T7, a transport ox belonging to the owner of Farm 3 died on the road. Anthrax not being suspected as the cause of death, the carcase wa~ placed upon a waggon, brought back to the farm, and there cut open. Blood-smears brought to the laboratory on the same afternoon showed anthrax. The carcase was therefore buried, and the

ABSTRACTS. 143

animals on the farm, consisting of seventy cattle and two horses, were inoculated on the evening of the same day with a iCc. of single vaccine (L) and kept from work for about three weeks thereafter. On the tenth day after inoculation one ox developed a swelling of the right fore limb, from the elbow almost to the fetlock, very marked in the region of the forearm. Seen Qn the twelfth day the swelling was very pronounced, but less so than it had been two days previously. The animal was still able to walk about and graze. The temperature was 101"6° F. and blood-smear examination negative. In about a week from the time it was first noted the swelling disappeared. Between the tenth and sixteenth days two other animals showed slight swellings in the neighbourhood of the inoculation site, but these disappeared within a few days. Similar swellings were noted in two more cases between the sixteenth and twenty-second days, and in a sixth between the twenty-second and twenty-ninth days. One ox died from anthrax on the nineteenth day. A seventh animal developed a swelling on the twenty-fourth day, but did not come under the author's observation until ten days later. Development was stated to have commenced in the pre­scapular region, extending to the lower part of the dewlap and the right foreleg in the course of a day or two. When the case was seen on the thirty­fourth day after inoculation there was a marked swelling of the whole dewlap, and the right fore limb was swollen from the elbow to below the knee especially the forearm. The animal had continued to move about and feed as usual from the time the swelling was first noted, and at the time of inspection its appearance was bright. The temperature was then 105'6° F. On the same day, 22nd February, this ox was transported to the laboratory and there kept under observation until the loth March, by which time the swelling had completely disappeared from the dewlap and the limb. On admission the forearm was punctured with a hypodermic needle, and the liquid thus obtained was examined microscopically and culturally. Rare bacilli morphologically resembling anthrax were present in Giemsa and methylene-blue stained preparations, some containing small refractile points Qf different size in their interior, and some" ghost" forms were also present. From this examination it appeared that these organisms represented anthrax bacilli which had undergone degenerative changes. Culturally no growth whatever was obtained on agar and in broth heavily inoculated. Eight mice and three guinea-pigs were injected-the former receiving icc, each sub­cutaneously, and the latter 2'2 and 4'5 cc. respectively - with negative results. On the day following admission the swelling commenced to decrease in size. The animal was bright and feeding well. Temperatures morning and evening were 103'2° F. and 104° F. respectively. From this time onwards the swelling continued to decrease, and the temperature returned to a practically normal level, with the exception of evening records Qf 103° F. and 103'2° F. on the 25th and 27th February respectively. The animal continued to feed well and to appear bright, and on the 27th painting Qf the skin over the swollen region with iodine tincture was instituted, the leg and dewlap being thus treated on alternate days for a week. The swell­ing steadily subsided, first from the dewlap and later from the leg, until by the 7th March it had completely disappeared.

Farm 4.-Twenty head of cattle running on Farm 4, on or in the neigh­bourhood of which anthrax had not been existent, were inoculated behind the shoulder with icc. of single vaccine (L) on 26th January 1917. On the 1st February it was noted by the owner that in one animal the forearm of the limb of the inoculated side was swollen. The farm happened to be near the laboratory and the animal was procured for observation on the 2nd February. At time of admission forearm markedly swollen from immediately

144 ABSTRACTS.

below elbow-joint to carpus. Less marked swelling between carpus and fetlock. Slight swelling of the lower part of dewlap, extending posteriorly to between the forelegs. Animal walked Ii mile to laboratory from farm without difficulty, feeding and ruminating as usual. Appears bright, tem­perature 106'8' F. Blood smear negative. On palpation of swelling of dewlap, and upper forearm, fluctuatIng character evident, and contents appear to be in great part liquid. Forearm punctured with hypodermic needle and the clear slightly yellow liquid, slowing freely from the needle, collected and examined. Microscopically, Giemsa and methylene-blue stainIng revealed rare but typical anthrax bacilli. Cultures made from the liquid on agar slopes and ordinary broth showed a well-developed pure growth in all tubes in twenty hours. Four gumea-pigs and four rabbits were injected subcutaneously from the broth cultures, in order to determine the virulence of the strain. Four guinea-pigs all died within the usual period within which the single vaccine produces death when tested for virulence, while the four rabbits survived. The organism isola:ed therefure appeared to possess the same degree of virulence as that present in the single vaccine originally injected into the animal on the z6th January. 3rd February: Temperature, morning 104'Z' F., evening lOS' F. The swelling appeals to have increased below the knee. Animal appears bright and is able to rise without assistance. From this day onward the leg was fomented daily with a warm 5 per cent. carbolic acid solution. 4th February: Tem­perature, morning 101 'S' F. evening loz'6' F. Appears bright and feeds well. Blood-smear examination negative. 5th, 6th, 7th, and Sth February: Temperature taken once daily on these dates were respectively :;04'6', 104'4', loz'8°, and 102'Zo F. Swelling about the same. Animal bright and feeding. 9th and loth February: On the 9th the swelling of the dewlap commenced to decrease in size, and this decrease appeared more marked on the loth. Temperature on evening of the loth, IOZ' F. I nh February: Temperature, morning ro [' F., evening 102'2° F. Swelling of dewlap still decreasing. 12th February: Temperature, morning 10l'Zo F., evening 102'2' F. Swelling in dewlap has almost completely disappeared, and that of leg commences to decrease in size. 13th February: Temperature, morning 100'F., evening 102'6' F. The temperatures on the 14th, 15th, and 16th February were, on the mornings and evenings of each of these days, lor', 10Z',

100'6',103',102', and 102'4' F., respectively. On the 16th the swelling below the knee had completely disappeared, by which time the swelling had also practically gone from the forearm. The animal was discharged on the 17th February. In this animal the swelling therefore appeared about the fifth, and remained up to about the twenty-second day after the inoculation. The strain of anthrax organism recovered from the swelling corresponded in virulence to that used for the preparation of the single vaccine, so far as could be determined from the small-animal inoculation tests. It is also to be noted that the animal had been running on veldt not known to be infected prior to or since the performance of vaccination.

Farm 5.-0n this farm, tenanted solely by natives, nine cattle had died from anthrax before vaccination was carried out. These deaths took place in January 1917, two on the 21St, one each on the 22nd and 24th, and five on the 25th of that month. The carcases of the first two had been opened and part of one eaten before the arrival of the police. Portions of the other were being dried as biltong, but were buried on police instructions. On 26th January the remaining 270 head were inoculated, each with t cc. of single vaccine (L), under the direct supervision of the author. One ox appearing sick on this day-temperature 102'4' F.-was not inoculated until all the others had been injected. It had recovered on the 30th

ABSTRACTS. 145

January, when the farm was next visited. Twenty deaths occurred from anthrax subsequent to the injection, as follows: two on the second day, three on the third day, three on the fourth day, four on the sixth day, two on the seventh day, one on the ninth to tenth day, one on the tenth to eleventh day, one on the eighteenth day, one on the fortieth day, one on the forty-first day, one on the forty-ninth day. On the forty-fifth day after the inoculation, the survivors were reinoculated, 99 with single vaccine (I) and 151 with single vaccine (L), all with a icc. dose on this occasion. Four days later another death from anthrax occurred, but thereafter no further mortality was observed. On 30th January one group of eight cattle, and on 31st January another group of the same number, were noted to be sick and not feeding well. In the majority of cases the temperature was elevated, in some considerably so. Of these sixteen animals ten recovered and six died.

In all, nine cattle out of the 270 showed swellings, which appeared on different dates. In three of these they appeared on the fifth day after inoculation. In one the swelling was situated on the right side of the lower part of the dewlap; in another it was present on the upper border of the neck in its posterior third and about the size of two fists. In the third the site of inoculation was swollen. In the fourth case the left fore leg and front of the shoulder were swollen from the sixth day after inoculation. When seen on the ninth day the temperature of this animal was 105'4° F. Blood - smear examination negative. Four others showed swellings, appearing between the seventh and ninth days at the inoculation site. The temperature of the one in which the swelling was largest was 105'8° F_ on the ninth day. Blood - smear examination negative. In the ninth animal the lower part of the dewlap was very swollen from the twelfth day. On the sixteenth day the temperature was 107'6° F., and blood­smear examination negative. On the eighteenth day this animal died from anthrax. In the other cases the swellings had disappeared by about the sixteenth day, with the exception of the fourth, in which the swelling of the fore leg remained a few days longer.

The following instances of post-vaccination accidents occurred in equines and goats:-

On a farm on which vaccination was carried out because of the death of a bovine from anthrax shortly before, several hundred bovines and fifty equines were inoculated with -l- cc. of single vaccine (L). Twenty-six of these equines were geldings, and none of these showed untoward symptoms; but of twenty-four mares injected with the same material and using the same syringe immediately after the geldings quite a number showed more or less extensive swellings. One of the mares, inoculated in the neck after due disinfection of the inoculation site, was described by the owner as much swollen on the neck and shoulder a day later and markedly lame. Her respiration was quickened and appearallce distressed. On the day after the swelling had decreased in size in the shoulder region, but now involved the head, which on the third day was very much enlarged. Puncture of the skin allowed the escape of a yellowish serous fluid. On the fourth day she appeared slightly better, but the lips were now somewhat more swollen than before. During all this time she did not feed, and death occurred a few days later. In two other mares, said to have appeared very near to death before recovery eventually took place, the swellings remained for a week before finally disappearing. The owner mentioned that at the time of inoculation all the mares were "very low in condition and had foals at foot."

In another case two mares died fifteen and thirteen days respectively

q6 ABSTRACTS •

.after inoculation of single vaccine (L), i- cc. dose. In the first of these, swellings containing an amber-coloured gelatinous material were observed post-mortem. One was situated on the near side of the trunk; another, measuring 20 by 18 inches, on the under l'.spect of the thorax; and a third, of consid<:!rable size, was present on the inside of the near thigh. No swelling was noted in either case at the site of inoculation. Post-mortem .ciecomlJosition did not allow of complete examination of the second animal.

A number of goats were inoculated with single vaccine (L) t cc. dose, and within eight days between forty and fifty died. Before death a number showed swelling of the inoculated limb, extending down to the hock, .and underneath the abdomen and thorax. In six blood smears out of twelve submitted from dead animals anthrax bacilli were found.

The preceding records illustrate the types of post-vaccination accidents ,encountered, and show that in character they are similar to those which have been associated with the application of the Pasteurian system in many .other parts of the world. Although long and well recognised, their origin, nevertheless, remains somewhat obscure.

In reviewing the cases taken for illustration, the author does not consider that the accidents are at all to be explained on the lines' suggested by Chamberland, since they have been chosen as examples of imtances where the vaccine was inoculated with all due care and with full observance ·of the conditions of cleanliness required. On one of these farms (Farm 5) the inoculation was carried out under the author's direct supervision, on three others (Farms 2,3, and 4) by lay officers of the veterinary service, and on Farm I by an individual possessing considerable previous experience {)f the operation. That they are to be accounted for by the existence of a ,latent infection, in the sense of Leclainche and Vallee, is an explanation also difficult to accept. The possible existence of such an infection might be admitted for those animals on the farms where anthrax was known to be present, but in two cases (Farms I and 4) there was no reason to ·suspect this. The history of both cases showed that no deaths from .anthrax had occurred in the herds before inoculation, and that the animals were not exposed to infection after the operation. Yet, on one farm, -33 out of 134 animals developed swellings and one died. On the other .only one animal showed a swelling, and from this it was possible to recover ,a strain of organism corresponding in virulence possessed to the attenuated -strain of bacillus used in preparing the vaccine injected.

In regard to the possible influence of the vaccine strains upon the ,in-::idence of the post-vaccinal accidents, it is pointed out that in all the cases -cited the single (L) variety was injected in -!- cc. dose for bovines (t cc. one case) t cc. for equines, and t cc. dose for small stock. Since this -strain possesses a degree of virulence closer to the second of the two vaccines used in the double method, it might be held by some as to be in a certain measure responsible tor the results. Such explanation, is, peihaps, admiss­ible where animals such as. equines, sheep, or goats are concerned, but is less possible in bovines, and it is to be remembered that similar accidents have been recorded in other countries as following the use of the ,classical double method. To infection by subcutaneous inoculation, even with fully virulent cultures, bovines are known to be very resistant. Oemler is quoted by N ocard and Leclainche as having only succeeded in producing ,death by this means in one out of forty-one animals, and it is, therefore, not surprising that cattle stand injection with single vaccine in doses much 1arger than usually employed without outwardly apparent effect. The :absence of external symptoms after a dose of I cc. instead of the usual -!- cc. -of the single vaccine was noted in two field experiments with seventy-six and

ABSTRACTS. 147

seventy-five head of cattle respectively. The author also mentions that in preliminary tests made on some hundreds of cattle, t cc. appeared to be borne so well that it is now adopted as the dose in general use in the field wherever single vaccination is still practised.

Moreover this manifestation of resistance is not confined to injection of the single vaccine. In one test made by the author, fifty-five cattle, not before inoculated, were directly injected with i- cc. each of the second culture of the double vaccine, without any externally visible result. Since then it has been noted that Grandmougin, in view of Oemler's experience, also came to consider that the second vaccine might be injected direct, thus saving the inconvenience of performing two inoculations on native-owned <:attle, and being satisfied with preliminary tests, subsequently carried out inoculations of some thousands of cattle in Madagascar, using one direct injection of icc. of the imported Pasteur second vaccine.

The author quoting Leclamche and Va lee asks, ,. How, then, can one explain the fact that one-quarter cubic centimetre of a virus so weak as the first vaccine, which will hardly kill a rabbit, is liable to set up in certain individuals of the bovine species a virulent and fatal attack?" He thinks that two factors suggested as causing the accidents, injury and work, may play a certain role in their production in some, although not in .all, of his cases. On Farm 1 the animals were put to work forty-eight hours after vaccination, but on Farms 2, 3, 4, and 5 they were simply left to graze over the veldt. On the whole, however, he is of opinion that M'Fadyean's view that all the post-vaccination accidents are ultimately dependent upon the possession by the animals affected of a degree of individual resistance below the average, offers the most feasible explanation for their occurrence. But whatever may be the final conclusion as to their causation, a point of practical importance, confirmed by the experience in South Africa, is that the risk of encountering them is much increased by .the use of the single vaccine. On this account the issue of this type ·of vaccine for the injection of equines, sheep, and goats, was completely dis­continued in March 1917, and restrictions were placed upon its use for cattle at the same time. Since then a large amount of the double vaccine has been issued and the results with this would certainly appear to be more satisfacto,ry so far as the risk of accident· production is concerned. During the last fifteen months only three cases of post-vaccination accidents have been reported. One of these relates to the occurrence of mortality :amongst sheep, and the second and third to the appearance of swellings at the inoculation site in a very few cattle and donkeys respectively. The 11rst of these cases, however, could also be accounted for through very probable natural infection existing at the time of, or developed shortly after, the vaccination; while the other two, even if not explainable except as <lirectly due to the inoculation, are not regarded as occurrences of character sufficiently serious to cause alarm.

Failures 0/ Vaccination to produce Immunity.-In proof of the general benefits of Pasteurian vaccination, extensive statistics collected in a number -of countries where it has been applied on a large scale have .been published in different places.

Lukacs states that the system of cultural vaccination has been practised 'according to regulations for more than twenty-five years in Hungary, and that he has succeeded now in finding a most efficient !protection against anthrax without serious complications. The statistics regarding the vaccina­tion of animals in healthy and infected herds furnished by him show that: (I) of 8, I 50,6 50 healthy animals vaccinated there were after vaccina­tion 4493 dead, viz., i- per mille; within a year, in spite of vaccination,

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there were 10,951 deaths, viz., t per mille. (2) Of 411,654 animals exposed to infection before vaccination, hence suspected of infection, there were 1493 dead, viz., t per cent, and, in spite of vaccination within a year 3050, viz, ! per cent. In the following table Lukacs gives the actual numbers of each species inoculated and other details:

I£ealthy Anz'mals Inoculated. ,

Deaths.

Species of Animal. Number. Between In Spite 1st & 2nd Per cent. ar Per cent, Inocula- Vaccina-

tion, tion.

----------------- ---------- ------ ------

Sheep 4,034,43 2 40 74 0'1 9177 0'25

Cattle 3,9 20,35 0 369 0'01 143 2 0'04

Horses 195. 861 50 0'02 142 0'06 ---------- ---- --------

Total 8,150,643 I

4493 0'°5 10,75 1 0'13

Anz'mals Inoculated in Herds Exposed to Infection at Time if Inoculation.

Species of Animal. Number.

Deaths. -----------------,-----------------

Between 1st & 2nd Inocula-

tion.

P,r cent. In Spite

of Vaccina­

tion.

Per cent,

----------------- -------- --------------------

Cattle

1'1

II82 ! 0'5

I

I 1849 Sheep

Horses 2,680 13 o'S 19 I 0'75 ______ , ______ 1. __ _ Total 1493 I 0'3 3050 ! 0'75

If these statements and a reasonably large experience In South Africa be taken to indicate that Pasteurian vaccination has generally a high degree of efficacy, and usually confers a protection lasting from at least nine to twelve months, explanation has to be found for those cases in which breakdowns in: immunity have occurred within the nine-months' period. In a large number of the cases reported there is no doubt that the unsatisfactory results should be attributed either to the use of a non-potent vaccine or to improper technique in performing the inoculation. It is known that on occasions the vaccine has been kept for several months or even up to a year before use, and it is also recognised that through clumsy manipulation of the hypodermic

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syringe, or errors made in attempting to separate inoculated from uninocu­lated animals at the time of the operoition, many individuals escape injection. That all cases, however, are dependent upon one or other or both these pos5ibilities cannot be accepted. Even should it be maintained that the imported vaccine used on Farm 6 may possibly have lost potency, although used in reasonably fresh state, this leaves the other two cases to be accounted for. In neither of these is there any reason to doubt the proper performance of the inoculation, while possible non-potency of the vaccine is considered ruled out through the use of the locally prepared fresh material.

.Farm 6.-0n Farm 6 two bovines of a herd of about 177 died on 13th October 1913 and anthrax was diagnosed as the cause of death. The remaining I7 5 animals were inoculated with icc. of double vaccine (I), the vaccination being completed hy the 7th November. Despite this vaccina­tion, however, deaths still continued to occur j and, although a second inoculation with double vaccine (I) was carried out in January J914, forty­one animals had died up to the 14th March following. Between this date and 8th May three more died, and later in May two deaths occurred, one on the lIth and another on the 14th. On the 12th June 1914 two deaths were reported, and another occurred on the loth July. On the 14th July 1914, the survivors of the herd were again inoculated, this time with single vaccine (I) in the dose of icc. Following this injection one death occurred on the 31st July, one on the 11th August, one on the 6th September, one on the 5th November, one on the 13th November, and one on the 30th November. On 3rd December 1914 fifty animals were injected with ~ cc. of second vaccine (I) preparatory to injecting the rest of the herd with this dose if the mortality continued; but, as no further deaths occurred during the year that followed, inoculation of the remaining animals with the t cc. of second vaccine was not carried out.

Farm 7.-0n Farm 7 anthrax appeared amongst a herd of bovines, numbering about 1100 head, in the latter part of September 1916, seven animals dying of the disease at that time. On the 1st, 2nd, and 3rd of October the remaining animals were inoculated with icc. of single vaccine (L), and between this last-mentioned date and the 26th October a further nine deaths occurred. Two of these took place within the first week after the inoculation, four from the tenth to the fourteenth days after, and three within the twenty-first and twenty-third days. A second supply of vaccine (L) being then obtained, the herd was again inoculated between the 1St and 3rd of November 1916, that is a month from the time of the first inoculation. On this occasion the dose injected was icc. per animal. On the sixth day following this vaccination one animal died of anthrax. There was then no further deaths until the lIth of January 1917, when two more animals died. In the latter part of the same month another two died, one on the 24th and one on the 26th January. In February 1917 five deaths occurred: one on the 2nd, one on the 8th, and three between the 19th and 21 st. At this time seventy-five of the herd were reinoculated with a dose of 1 cc. of single vaccine (L), as it was intended to inject the remaining animals with this increased dose if deaths continued to occur. The mortality ceasing, how­ever, the remainder of the herd did not receive the increased dose. No further deaths from anthrax have since he en reported from this farm. In the latter part of 19 I7 the herd was again vaccinated, double vaccine (L), injected in the dose of t cc., being used. Amongst the seventy-five animals inoculated with 1 cc. dose of single vaccine no ill effects were noted except in a few cases in which a slight swelling at the site of inoculation was noted, extending in some animals also to the forearm of the same side. These swellings, however, soon disappeared.

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Summary.-In this case seven deaths had occurred before vaccination with icc. doses of single vaccine (L) was carried out. Within the first week following this inoculation two animals died. Four more died between the tenth and fourteenth days, and three deaths between the twenty-first and twenty-third days. On the thirtieth day after this inoculation another injec­tion of single vaccine (L) was made with a dose of ! cc. Six days later one animal died of anthrax. Deaths then ceased until the seventieth day from this last inoculation-or one hundred days from the first vaccination-on which day one occurred. One animal died on each of the eighty-third, eighty-fifth. ninety-second, and ninety-eighth days subsequent to the second inoculation. and three more died between the one hundred and ninth and one hundred and eleventh days. Seventy-five animals were injected with a I cc. dose of single vaccine (L) a few days after the last-noted deaths occurred. None of these died, neither did any of the remaining animals which were not inocu­lated with this larger dose, the mortality ceasing with the deaths recorded on the one hundred and ninth to the one hundred and eleventh days after the second injection. Another vaccination, in which double vaccine (L) in the dose of t cc. per head was given, was carried out in the latter part of 1917" and no deaths from anthrax have since been reported.

Farm 8.-0n the 16th December 1915, a working ox suddenly became ill and died in the yoke, and on microscopic examination of a blood smear­from it anthrax was diagnosed as the cause of death. From this time onwards deaths from anthrax continued to occur up to October 1917, the total number of deaths being thirty-one, including nine oxen, eight cows, six heifers and tollies, three calves, one mule, two sheep, and two pigs. The number of the owner's cattle on the farm at the time the first death took place was 3I7, made up of 139 oxen, seventy-two cows, thirty-six heifers, seven tollies, one bull, sixty-two calves. In addition there were 200 native­owned cattle on the farm. Anthrax may have been existent on the farm prior to this outbreak, since in previous years a number of deaths of different species of animals had occurred. These, howe·ver, had at that time been attributed to other causes. The farm was divided up into a number of parts. which may be distinguished respectively as A, B, C, D, and E. All the owners's cattle were running on the portions A and B; the native-owned cattle grazed on the portion C; and the pigs were styed in a camp, the vicinity of which they did not leave, on portion D. All of the animals· which died were watered from a dam situated on portion A, or else drank from kuilen, or waterholes, above or below this dam on portions A and B.. It was noted that there were fewest deaths among the animals drinking from the kuilen on portion B, and those of this lot which did die also had access to the water at the dam, or in its immediate vicinity, on A at some or other­times. In April 1916, Veterinary Research Officer Andrews collected from this dam a sample of water mixed with mud stirred up from the edge, and succeeded in proving the presence of anthrax spores in it. This dam is· believed to have been the principal source of infection. No deaths from anthrax occurred among a large number of animals watered from boreholes on the portions D and E. The pigs which died in D portion are believed to· have contracted the disease from portions of carcases fed to them before the· deaths which occurred in the first part of the outbreak were recognised as due to anthrax. Once the existence of anthrax was definitely recognised aU animals dying from that time onwards, whatever the cause of death, were buried deeply and intact. Since the dam was finally fenced off at the com­mencement of December 1916, there have been very few deaths, and these have occurred only amongst animals with access to the kuilen on portion A close to the dam, when the water was very low and muddy. Following the

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death of the above animal on the 16th December 1915, one ox died on the-29th of the same month. On the 5th January 1916 another ox died, and on the loth January the deaths of a cow and a yearling took place. On IT th and I zth January, all of the owner's cattle were inoculated with single vaccine (I) -1- cc .. dose, and on 11th February all native-owned cattle were inoculated with single vaccine (L), i- cc. dose. On the loth February an uninoculated mule died. Subsequent to these above inoculations a number of others were carried out at different limes. Some of these were primary vaccinations of newly introduced animals and others were repeated vaccina­tions of animals previously inoculated. Some anImals received as a fina1 dose even I cc. of vaccine.

On 4th December 1916 the dam on portion A of the farm was enclosed, and in February 1917 the stock were reinoculated with double vaccine (L). Deaths since then have been one toUie on I zth March 19 I7 ; one tollie, 8th May 1917 ; one calf, 3rd June 1917 ; one cow, 9th October 1917 ; and one pig, 19th October 1917. It is not known how this last animal contracted infection. In March 19 I 6 the horses and sheep on the farm were inoculated with double vaccine (L), i- cc. and k cc. doses respectively. The animals which received a final dose of I cc. second vaccine (L) in 19 I 6 were twenty oxen inoculated on roth April; twenty-five yearling cattle inoculated on 18th April; and forty·one cattle (thirty·eight tollies and heifers, and. three cows) on 5th May. Of these only one died, death taking place on 8th May, three days after the inoculation. This animal had previouslY' received two inoculations, with -l- cc. single vaccine (I) and t cc. second. vaccine (L) respectively.

The author considers that the experiences on the last two falms represent genuine failures to produce immunity. To explain them it would seem necessary to postulate the existence of two sets of circumstances, one primarily connected with the vaccinated animal, and the other with its environment after inoculation. The former is probably the less important, but raises two possi-­bilities: (a) that some individual animals are so resistant to vaccination that the reaction called forth is not sufficient to produce a significant subsequent immunity. It is difficult to estimate the extent to which this assumption is true of species such as equines, sheep, and goats, but with a species such as the bovine, where resistance to subcutaneous infection with even relatively virulent strains is generally recognised, failure to react may perhaps not infrequently occur. (b) That even when the vaccine has definitely conferred a fair degree of immunity infection may still occur under conditions which lower the general physiological resistance of the animal Amongst conditions operative in this direction may be included anremia due to helminthiasis or other causes, exposure to excessive heat or cold, or to cold rains, and possibly even dipping. It is not likely, however, that. either of these possibilities cover more than a small proportion of obselved vaccination failures, and for the majority of cases of ineffective inoculation environmental conditions of infection offer the more plausible explanation. The breakdowns may then be interpreted on a quantitative or qualitative

. basis, and be regarded as due either to continued exposure to a very heavy natural infection, or perhaps to the existence of peculiarly virulent strains of the anthrax organism in certain localities. The pre~ence of abnormally heavy infection on a very large number of South African farms must be admitted in view of the widespread negligence in regard to the disposal of anthrax carcases, and it is strikingly illustrated in relation to the water supply of Farm 8. The extent to which differences in degree of post­vaccination immunity can be attributed to differences in degree of patho­genicity of certain strains offers a promising field for experimental inquiry,

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and investigations in this direction have already been commenced at the Government Laboratory. On grounds of analogy with other disease variability is a pn'ori a tempting hypothesis, and in regard to anthrax it is already recognised that very marked differences in strain virulency may exist. The contingencies outlined in this section have been kept in view in considering the failures reported in connection with the use of the " L " vaccine, and have served to suggest certain modifications in the application of the Pasteurian system of vaccination in South Africa. One of the modifications already instituted consists in doubling the ordinary dose of vaccine for all animals except equines. Since January 1917

the dose adopted has been t cc. for cattle and a icc. for equines, sheep, and goats. The increase in dosage facilitated quantitative injection, and is regarde as inducing a more vigorous reaction.

Another modification, recommended in dealing with immunity break­downs, involves the revaccination of the whole troop or fluck, followed by repeated injections of second vaccine in doses doubled at intervals of a fortnight until mortality ceases. In this way repeated reaction may be elicited and a stronger immunity conferred. In practice the effects of injection of quantities higher than 1 cc. have not come under observation so far, since mortality has usually ceased after the second inoculation of second vaccine. If, however, it is definitely established by future observation that such inoculation with the strains at present used in preparing the vaccine is not sufficient to afford protection against certain unusuilly virulent local strains, the problem of polyvalent multiple vaccines will have to be faced. A vaccine incorporating various local strains may have to be aimed at or special vaccines may have to be attempted for the districts in which strains of peculiar virulence are dominant. The execution of laboratory trials has already been commenced, and strains are being collected from various parts of the country from animals which break down in immunity after inoculation with the vaccine now in use.

In conclusion the author commends the following quotation from an article by M'Fadyean for consideration by the various owners of stock throughout the country on whose farms anthrax occurs: "M. Pasteur himself, before he had discovered the method of vaccinating with attenuated cultures, declared in very precise language his belief in the easy extinction of anthrax (' J e crois fermement a la facile extinction de ce fleau ') by the exercise of proper care in disposing of animals dead of the disease. In support of this belief he cited a most instructive case, in which the annual loss from anthrax on one farm had in ten years been reduced from a hundred animals to three, by the simple precaution of burying every anthrax carcase in a special niece of ((round fenced off so as to prevent the access of animals to it." (Daniel Kehoe. Fifth and Sixth Reports of the Director of Veterinary Research, Union of South Afn'ca, 1918, pp. 2 I 1-253).