10
ABSTRACTS AND REPORTS. be taken as 2,000,000, this means a loss of 6,000,000 kronen per annum that is avoidable. The results obtained in the Skjaerum district show that if the destruction of the fly is carried out energetically and methodically good results may be expected with ·certainty. (Villemoes, Zeitschr. j Fleisch. u. Milchhygiene, Vol. XXI., NO.9, June 19II, pp. 277-279.) MALTA FEVER IN THE DOMESTICATED ANIMALS. MALTA fever is a specific, inoculable, contagious disease, common to practi- cally all the domesticated animals and to man, and is caused by the micrococcus melitensis (Bruce). The disease principally affects the goat, in which animal it is responsible for many cases of abortion. Historical.-The disease was first described by Marston in 1859. This author saw a number of cases among the inhabitants of Malta and was himself attacked. In 1879 a very fatal epidemic at Catania was described by Tomaselli. From this time onwards the disease was recognised at practically all parts of the Mediterranean littoral and it was known under the following synonyms: Rock fever, Naples fever, Crete fever, Cyprus fever, Levant fever, Mediterranean fever. The causal organism, the micrococcus melitensis, was discovered and described by Bruce in 1887, and ten years later Widal's agglutination test was applied to the diagnosis of the disease by Wright. In 1904 a Commission was appointed by the British Government to investigate the disease, and it was then found that the principal vehicle of infection for the human subject was goat's milk. The discovery was made by Zammit, who, while testing the agglutinating power of the serum of six goats, found that five of them agglutinated the micrococcus melitensis and that the organism was present in the blood of two of them. The blood of forty-six goats was then examined and it high agglutinating power found in seven of them. The prophylactic measures put into force furnished an indirect proof of the danger run by human beings in using the milk of infected goats. In May 1906 the banning of goat's milk and cheese made from the same material, as part of the rations of the entire garrison, which was decimated by the disease, led to a con- siderable decrease in the number of cases among the military, whereas, among the civil population, which was not put under this regulation, the incidence of the disease did not vary at all. Other authors showed that in addition to infection by the milk the disease might be contracted by simple contact with goats. In France the disease appears to have been observed for the first time in 1901 by Roustan, who encountered an epidemic at Cannes. It is unfortunate that in this outbreak serum diagnosis was not resorted to. In 1908 Wurtz, Danlos, and Tenon encountered an outbreak in a model goat dairy near Paris. d' Aubert, Cantaboule and Thibault described, in 1909, an outbreak originating among the goats at Saint-Martial and Lagrifoul; Arnal and Roger published an account of a small epidemic at Saint-Bauzille-de-Montmel. Investigations carried out by the French Government brought to light some important facts. The disease, instead of being limited to a few villages, was found. to be widely spread over the whole of the department of Gard. More than 400 cases were observed in the human subject in less than a year. The disease was found in'animals other than the goat (sheep, dogs, horses, fowls, and ducks). Finally, the principal clinical features of the

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Page 1: Malta Fever in the Domesticated Animals

ABSTRACTS AND REPORTS.

be taken as 2,000,000, this means a loss of 6,000,000 kronen per annum that is avoidable.

The results obtained in the Skjaerum district show that if the destruction of the fly is carried out energetically and methodically good results may be expected with ·certainty. (Villemoes, Zeitschr. j Fleisch. u. Milchhygiene, Vol. XXI., NO.9, June 19II, pp. 277-279.)

MALTA FEVER IN THE DOMESTICATED ANIMALS.

MALTA fever is a specific, inoculable, contagious disease, common to practi­cally all the domesticated animals and to man, and is caused by the micrococcus melitensis (Bruce).

The disease principally affects the goat, in which animal it is responsible for many cases of abortion.

Historical.-The disease was first described by Marston in 1859. This author saw a number of cases among the inhabitants of Malta and was himself attacked. In 1879 a very fatal epidemic at Catania was described by Tomaselli. From this time onwards the disease was recognised at practically all parts of the Mediterranean littoral and it was known under the following synonyms: Rock fever, Naples fever, Crete fever, Cyprus fever, Levant fever, Mediterranean fever.

The causal organism, the micrococcus melitensis, was discovered and described by Bruce in 1887, and ten years later Widal's agglutination test was applied to the diagnosis of the disease by Wright. In 1904 a Commission was appointed by the British Government to investigate the disease, and it was then found that the principal vehicle of infection for the human subject was goat's milk. The discovery was made by Zammit, who, while testing the agglutinating power of the serum of six goats, found that five of them agglutinated the micrococcus melitensis and that the organism was present in the blood of two of them. The blood of forty-six goats was then examined and it high agglutinating power found in seven of them. The prophylactic measures put into force furnished an indirect proof of the danger run by human beings in using the milk of infected goats. In May 1906 the banning of goat's milk and cheese made from the same material, as part of the rations of the entire garrison, which was decimated by the disease, led to a con­siderable decrease in the number of cases among the military, whereas, among the civil population, which was not put under this regulation, the incidence of the disease did not vary at all. Other authors showed that in addition to infection by the milk the disease might be contracted by simple contact with goats.

In France the disease appears to have been observed for the first time in 1901 by Roustan, who encountered an epidemic at Cannes. It is unfortunate that in this outbreak serum diagnosis was not resorted to. In 1908 Wurtz, Danlos, and Tenon encountered an outbreak in a model goat dairy near Paris. d' Aubert, Cantaboule and Thibault described, in 1909, an outbreak originating among the goats at Saint-Martial and Lagrifoul; Arnal and Roger published an account of a small epidemic at Saint-Bauzille-de-Montmel.

Investigations carried out by the French Government brought to light some important facts. The disease, instead of being limited to a few villages, was found. to be widely spread over the whole of the department of Gard. More than 400 cases were observed in the human subject in less than a year. The disease was found in'animals other than the goat (sheep, dogs, horses, fowls, and ducks). Finally, the principal clinical features of the

Page 2: Malta Fever in the Domesticated Animals

ABSTRACTS AND REPORTS.

disease in the domesticated animals and the usual methods of infection were definitely determined. In spite of this, however, our knowledge of Malta fever in animals is not very extensive, and there are several important points requiring elucidation.

Bacteriology. - The micrococcus melitensis is a very small organism, rounded or slightly oval in shape, and measuring about 0'3 fJ- in its long diameter. It is non-motile. It is easily stained by the basic aniline dye8, but is Gram-negative.

Involution forms rapidly make their appearance on artificial media. The organism is ::erobic and the optimum temperature is 37" C. It does not cause fermentation of sugar solutions, produce indol, or coagulate milk. At the end of several days the reaction of the medium becomes alkaline. Even at favourable temperatures growth is slow and meagre. The best medium for the cultivation of the organism is 5 per cent. glycerine agar. Sown out on the surface of agar, it forms small transparent colonies which by the third day measure 2 mm. in diameter. After about ten days the colonies are circular and project slightly from the surface of the medium. They are glistening in appearance and milk-white or slightly yellow in colour. It grows with difficulty on the surface of gelatin without producing lique­faction. On the surface of potato, where it grows with difficulty, it forms a thin, moist, transparent layer. In broth growth is slower and less abundant than on solid media. After five to eight days at 37° C. there is a general turhidity without any formation of a surface film.

Resistance of the Virus-Kept at a low temperature and protected from light, cultures retain their vitality for several months j exposed to light at a temperature of IS° to 25° c., they rapidly die out.

The micrococcus melitensis offers considerable resistance to desiccation. It remains alive for sixty-nine days in dried sterile manure, eighty days in such materials as bed-clothes, sheets, etc. It may remain alive tor as long as seven weeks in urine, sterile or not. The organism offers a very feeble resistance to heat, disinfectants, and acids: I in 5000 potassium permanganate, I in 1000 salicylic acid, and I in 5000 carbolic acid kill it in ten minutes. Sublimate kills it very quickly. It resists in 45 per cent_ alcohol for ten minutes, for half an hour in 20 per cent. alcohol, and is immediately killed in alcohol stronger than 70 per cent It dies after five days in sterile water and in twenty days in milk_ At S° C. it lives only forly-eight hour5, and at 0° C. for five days (Fiorentini)_ It is killed by an exposure to the sun at sSo C. in one hour (Shaw)_ Pasteurisation of infected milk for ten minutes at 68° C. suffices to destroy it (Horrocks and Kennedy)_ In chee~es made with infected milk Shaw found numerous micrococci with great ease after forty-eight hours.

Animals Afficted.-The majority of the domesticated animals are susceptible to natural infection. The goat is most frequently attacked, but in France the sheep is equally susceptible. Exceptionally the disease is observed in the horse, mule, and large ruminants_ The diseafe has been found to cccur naturally among domestic carnivora and rodents_ Fowls and ducks may be affected exceptionally. One case is on record of Malta fever in a wild ibex_ Man is very liable to infection.

Epidemiology_-The disease has been recogni5ed in almost every part of the world. In Europe it is principally the countries bordering upon the Mediterranean that are affected_ It has been observed in Greece, Italy, all the islands of the Mediterranean, Spin (Gibraltar), and Turkey. France, until recently free, is now affected. In Asia, India is everywhere affected. The disease has been recognised in the north of Africa and in the Transvaal. In America it occurs in the valley of the Mississippi and in Venezuela and Brazil.

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2::2 ABSTRACTS AND REPORTS.

Clint'cal Examination.

I. Symptoms.-Goat. In the goat there are as a rule no visible symptoms, and the animals maintain to all appearances their good health, the onset of the disease always passing unnoticed. Sometimes in infected females it is observed that the milk turns as soon as it is withdrawn, but beyond this no other abnormality is seen. In certain cases this is observed on certain days only and it disappears sometimes for weeks at a time.

Fairly frequently during the course of the disease the animals suffer from a subacute or chronic bronchitis, which is manifested merely by frequent coughing.

The most important symptom and the one that should always make one suspect Malta fever is abortion, but even this is not constant, nor is it diagnostic. When the disease makes its appearance in a herd for the first time the percentage of abortions may be anything from 50 to 90 per cent. of the pregnant goats. If these goats are again served abortion occurs again, but the percentage is not so great as on the first occasion. Abortion may cease completely in a herd, but this does not make the danger any the less, as a certain number of animals always harbour the parasite. Sterility is rarely observed.

Abortion occurs in animals of all ages and at all periods of gestation, sometimes at the third month, rarely at the second, and most frequently at the fourth. It is not rare for abortion to occur only a few days before the normal period. In this case the fcetus is generally dead, or if living soon dies. The period elapsing between infection and abortion has not been accurately determined, but it is variable, since animals infected at the same time abort at different periods.

The symptoms preceding abortion are generally very indefinite, and they vary with the length of time that the animal has been pregnant, being more obvious at the later stages. The animal does not appear to be ill and feeds as usual. No change is observed in the milk. The expulsion of the fcetus occupies the usual length of time, and the fcetus appears to be normal. No untoward symptoms follow abortion. The animal appears to be in perfect health and the secretion of milk commences. The latter is always diminished in amount, but rarely completely suppressed. Very occasionally symptoms of a general infection appear, but this may be attributed to a post-partum infection. Fairly often there is a discharge of muco-purulent material or symptom, of a utero-vaginal inflammation. This disappears in about thirty or forty days without leaving any after-effects. Finally, various abnormalities, such as lameness, mammitis, and affections of the eye, may be observed in animals that have aborted. The cause of the lameness is generally difficult to determine; sometimes there is evidence of arthritis, but frequently there are no lesions at all. Mammitis, as a sequel to abortion, is as a rule not serious, and recovery takes place without treatment. This mammitis is marked by the app"arance of nodules about the size of hazel nuts in the substance of the gland and by a clotting of the milk. Sometimes a marked diminution in the secretion of milk follows. In one case of abortion followed by an infection of the genitals intl!nse conjunctivitis and keratiis appeared in both eyes. Recovery was rapid.

In he-goats the only morbid conditions caused are lameness and orchitis, the latter being very rare.

The Disease in Other Species of Animals.-In the sheep the symptoms shown closely resemble those seen in the goat, and, as in the goat, abortion is the most important symptom. In the horse, mule, ox, dog, cat, and rodents there are no appreciable symptoms. Finally, the disease sometimes amounts to a deadly epizootic among fowls. In all animals, independently of the

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AllSTRACTS AND REPORTS. 253

clinical symptoms, the blood serum, urine, and milk possess agglutinating powers for the micrococcus melitensis.

2. lesions.-Opportunities of examining the lesions of this disfase are rare because of the low mortality, but congestion and degeneration of the liver, enlargement of the spleen, and engorgement of the abdominal glands, without any change in the blood, have been observed.

In an experimentally infected goat Caracialo found subacute broncho­pneumonia corresponding with the "Mediterranean phthisis" described by Hugbes.

3. Diagnosis.-(A) Diagnosis during life :-(a) Clinical Diagnosis.-Diagnosis of Malta fever in the goat and sheep

outside an infected area presents many difficulties. Multiple cases of abortion without assignable cause alone raise a suspicion of the existence oi the disease. .

In infected countries diagnosis is also difficult. Diagnosis may, however, be aided by the presence of lameness in the two sexes, orchitis in the males and, above ail, abortion with its special features in the females. It frequently happens that an epizootic of abortion in goats coincides with an epidemic of Malta fever in man, and this is sufficient to establish almost with certainty the nature of the disease in the animals.

Nevertheless, whatever clinical symptoms be observed and whatever cletails be collected, no positive diagnosis can be arrived at without appropriate bacteriological examinations.

(b) Agglutination.-The value of this test is indisputable, but since the serum may retain its agglutinating power for years after all trace of infection has disappeared a positive result only indicates that the animal is or has at some time been infected. The important point would be to determine whether an animal is or is not infected at a given mome:1t. This, un­fortunately, in the present state of our knowledge, is impossible, and it is quite certain that many animals have been condemned that have not been a source of danger for a long time. Further, the agglutinating powers of the liquids of the body may vary considerably and even disappear at certain times in an infected animal (author's observation). It therefore appears to be unwise to conclude that the animal is not infected after a single negative test, and a repetition of the test is indicated after an interval of several dayf, at least in very suspicious cases.

The agglutination test may be carried out with milk (Zammit's test), blood­serum (Wright's test), or with urine from suspected animals. The serum test is the one to be preferred.

In all these cases one employs agar cultures of the specific organism. An emulsion is made with sterile distilled water of a four to eight days' culture, of a turbidity resembling a twenty-four hours' broth culture of Eberth's bacillu~.

The following is the technique of the serum test: One drop of serum is diluted with nine drops ot sterile distilled water in a capillary tube about 4-6 mm. in diameter and 6-7 cm. in length. The ten drops are then mixed with ten drops of the emulsion, thus giving a dilution of I in 20. For each tube there should be a control tube.

The result should be considered as positive when there is complete agglutination, both macroscopic and microscopic, after the following intervals: I in 20 in less than six hours, r in 30 in less than twelve hours, I in So or more in less than twenty-four hours. Occasionally one finds sera which agglutinate only feebly in dilutions of I in 20 or I in 10 and to a marked degree in the higher dilutions. In order to avo:d this source of error (para­doxal reaction), one should, theoretically, make two tests for each serum, the one I in 10 or I in 20 and the other I in 30 or I in So . . Practically it is sufficient to make a single test of I in 30, because on the one hand this

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254 ABSTRACTS AND REPORTS.

proportion IS more than sufficient to establish the specific nature of the reaction, and on the other hand one need have no fear of a paradoxal re.l.ction, which has not been observed with this dilution.

The technique for the milk and urine tests is the same, but these tests are fAr less exact and they should only be used when for any reason it is impossible to obtain serum. The culture used may be alive or dead; in the latter case agglutination is a little slower, but any risk of infection is avoided. Curry uses cultures that have been killed by heat at 60° C. for fifteen minutes, with the addition of 0'5 per cent. of carbolic acid. Other authors use cultures that have been killed by formol.

(c) M£croscopicand CulturalExamination.-The blood, milk, or urine may be examined for the organism.

It is apparently very difficult to isolate the organism from the blood of suspected animals. 4 or 5 cc. of blood should be mixed with 300 cc. of b roth and the whole placed in an incubator at 38° C.

The isohtion of the organism from urine and, above all, from milk, is relatively easy, and all the more so since these liquids contain large numbers of them. It is well known that the richness of these liquids in bacteria is very variable, and one may find them in large numbers on one day and almost absent on another. When the milk or urine contains only a few bac teria cultivation is aided by the addition of some drops of a sterile serum that agglu tinates the micrococcus mel itensis.

(d) I noCitlatt'on.-Inoculation of suspected materials, such as blood, milk, or urine, has only a limited application . The guinea-pig appears to be the best animal to use for the purpose. A high agglutinating power is conferred on the blood of guinea-pigs inoculated intra peritoneally with milk rich in the bacterium.

(B) Pust-mortem Diagnosis.-In the present state of our knowledge a cer tain diagnosis cannot be based on a simple examination of the car case. Experimental diagnosis is itself restricted in application. Examination of the organs or tissues usually affected does not as a rule yield positive results. The bacteria are present in small numbers only, and difficult to discover on account of their small size.

The inoculation of experimental animals is without result unless the material used is rich in the organism.

Artific ial culture on ordinary media appears to afford the best chance oj arriving at a diagnosis, and even this is uncertain. The spleen is the best organ for the purpose.

Agglutination tests with blood, urine, or milk taken from the dead animal may give as good results as in the case of living animals.

4. Prognosis.-Prognosis in the case of the sheep and the goat is generally favourable.

From an economic point of view the disease is a very serious one. Abortion may occur in 50 to 80 per cent. of the pregnant animals. This not only entails a loss of the produce but also leads to a number of seqllel<e, the commonest of which is a decrease, more or less serious, in the amount of milk.

In the other species of animals the disease appears to be of no importance, but there is the fear that the organism, with its capacity for causing abortion, may b ecome acclimatised to other species and produce the same ill effects in them as in the goat and sheep.

The most important point in connection with Malta fever is the ease with which it is transmitted to the human subject. In the latter the illness is generally long and troublesome, and the period of convalescence may extend to months or even years. Besides this, the disease sometimes manifests itself in the form of an epidemic.

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ABSTRACTS AND REPORTS.

Susceptibility.-All the domesticated animals are liable to infection, but the goat is most frequently attacked. Age or breed have no influence on the incidence of the disease, but sex appears to have considerable importance in this respect. Entire males are infected in a higher proportion than the females, and the kids of iniected mothers possess a certain degree of immunity.

In France sheep appear to be as susceptible as goats. The ox, horse, and domestic carnivora are equally susceptible to infection,

but in them the disease is more rare than in the goat and sheep. In France natural infection of the rabbit is of fairly frequent occurrence. Amongst poultry, fowls show a marked susceptibility to the micrococcus

melitensis. Methods oj Infection.

I. In the goat and sheep infection is principally due to the ingestion of milk or contact with milk or urine containing the organism. The latter is by far the more frequent.

(a) Infection by Ingestion oj Milk is Rarely Obserzled in Animals.-Kids born of infected goats do not, as a rule, become infected by drinking their milk. On the other hand, the progeny of non-infected animals may be infected by sucking infected goats, and these may hand on the infection to healthyanimals.

Milking is a common means of spreading the disease, the milker omitting to observe the most elementary precautions, and carrying the infection from goat to goat.

(b) Infection by Urine.-This appears to be the commonest means of infection. Infected animals void considerable numbers of the bacteria with .their urine, and these can retain their vitality in the bedding for long periods. It is often the case that the owner himself is infected, and by urinating in the sheds infects them. Besides, a person who, to all appear­ances, has recovered may still pass the specific organism with his urine. One can thus see how the disease may be introduced into a healthy herd by a shepherd who is the subject of the disease or convalescent.

(c) Transmission during Copulation.-Infection in this way is of very frequent occurrence, and the he-goat plays a very important role in the dissemination of the disease. In some experiments carried out by the author several hundred goats were examined, and the serum tested showed that 16 oer cent. of the females and 65 per cent. of the males ,were affected.

There are numerous observations to show that previously healthy districts have been infected by the introduction of a he-goat suffering from the disease. The he-goat naturally runs far greater risks of infection than the females, and, once infected, the infection is passed on to all subsequent females that he may cover.

Similar observations have been made with regard to the sheep, and it is ·quite likely that the same method of infection will be found to hold good among all the susceptible species.

2. Infection in the Other Susaptible Specz'es.-The small rodents become :infected by the ingestion of food contaminated by the urine of an infected animal, and, once infected, they may serve to form fresh centres of the disease.

The horse, mule, and ass may be infected by ingestion or by contact of the skin with soiled bedding while lying down or by contaminated harness through inoculation into small wounds.

The Saprophytic Origin 0./ the Disease.-The theory of the saprophytic origin of the micrococcus melitensis has not as yet been investigated. The organism lives for some time in water, urine, dry or moist dust, but it appears improbable that the disease c&n be transmitted in this way.

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ABSTRACTS AND REPORTS.

The theory of a saprophytic existence in the animal's body appears to be more plausible. This takes into consideration many points of etiology that are so far obscure, and explains particularly the appearance of Malta fever, as has often been observed, in animals that have not been exposed to the risks of infection for considerable periods.

Methods of Penetration of the Virus.-Experimentally the disease has been studied chiefly in the monkey, because of the knowledge that might be so obtained as to the methods of infection in man. The monkey is far more susceptible than the other animals, but appears to offer a greater resistance than man. Monkeys are not easily infected unless relatively large doses of culture are used. The period of incubation after subcutaneous Inoculation is two to five days, and eleven to fifteen days after submucous. The disease thus set up may last for months, and generally terminates fatally, the symptoms observed closely resembling those seen in man. The organism is to be found in large numbers in all the orgam, but chiefly in the spleen and liver, both of which are enlarged.

Outaneous infection is also possible. Shaw has shown that a monkey can be infected by placing the urine of a diseased animal in contact with excoria­tions. The same author has proved that monkeys can be infected by plac­ing dust that is highly contaminated in the eyes and nose, by close contact with diseased animals, and, finally, by the ingestion of food mixed with cultures, infected dust, or urine. A most important fact is that the milk of a naturally infected goat will transmit the disease. Finally, monkeys have been infected through the apparently healthy mucous membrane of the genital organs.

Eyre, Naught, Cannedy, and Zammit have shown that simple stabling of infected with healthy goats is sufficient to infect the latter. Subcutaneous and cutaneous infection are successful, and the same authors have proved that simple contact of a contaminated hand, as in milking, is sufficient.

Goats may be infected by ingestion or intravenous inoculation. Once infected, a goat rarely, if ever, becomes free from infection again. Trans­mission to the human subject by the bites of mosquitos is improbable, and, if it ever happens, it is highly exceptional.

Pathogenesis.-In the early stages of the disease in the goat the micro­coccus is in the circulating blood and in the spleen. The organisms then settle in the spleen, lymphatic glands, and kidneys. Their persistence in the spleen explains their appearance from time to time in the blood, and the possibility of infection of the muscular system. They disappear in turn from the kidneys, spleen, and lymphatic system, and only persist for a long period in the mammary gland.

About the third or fourth week after intravenous inoculation the organisms disappear from the blood and only reappear there at intervals for a variable period. The micrococcus can be isolated from the spleen as long as twelve to fifteen months after the onset of the disease.

The elimination of the micrococci by the urine also takes place at variable intervals, but it is not a constant feature of the disease. The excretion of the organism with the milk is not continuous. On some days not a single one may be found, and on others there may be as many as 30,000 per cc. Infection in utero has not been observed, but the agglutinin passes to the fretus.

The infective condition of the freces exceptionally seen in man has not been demonstrated in animals.

Treatment.-So far no drug has been found capable of arresting infection or altering the course of the disease. It is impossible to prevent the abortions that are due to this disease. The subcutaneous injection of carbolised water, which has in some cases given excellent results in epizootic abortion, might be tried as a preventive measure.

Page 8: Malta Fever in the Domesticated Animals

ABSTRACTS AND REPORTS.

Propllylaxis.

I. Immunisation.-The various attempts of Shaw and Eyre to prepare an immune serum by inoculating various species of animals with organisms living or dead or their toxins have not met with success. Attempts made by the same authors to produce a vaccine also failed.

Quite recently Vincent and Coltigon stated that they have prepared a vaccine for the protection of animals.

2. Hjgienic Measures:-In the absence of any vaccine, protection from the disease must be sought in suitable hygienic measures. The number of susceptible animals and the various methods of infection render these complex.

The fact that the sheep and the goat are most frequently affected indicates that the principal efforts should be directed towards these species. Efforts should be directed towards preventing the introduction of the disease into a healthy herd, and to stamping out epizootics. In practice the first of these is difficult of realisation. '

The freedom of a herd can only be guaranteed under the following con­ditions: that animals are never introduced into a healthy herd from one in which abortion has occurred; in the event of exact information as to this not being forthcoming, to quarantine fresh purchases for a time sufficiently long to enable one to ascertain that parturition is normal; wben abortion occurs in a fresh animal to isolate it immediately, destroy the fcetus and membranes, and disinfect the fioor, litter, and walls of the stable that ha\'e been contaminated by the animal.

The bringing together of animals belonging to different owners for the purpose of serving the she-goats should be absolutely abandoned.

Only absolutely healthy males should be used, and they should be exa­mined several times yearly. Further, the genital organs should be cleansed and disinfected after each service.

Even quarantine of fresh animals in many cases does not prevent the introduction of infected animals, and it is difficult to judge the state of health of the males by clinical examination. It would be necessary to carry out systematic serum tests of all fresh purchases and en tires.

These measures, even if carried out strictly, are not sufficient to prevent the introduction of infection, since otber animals, such as dogs and rabbits, may act as bearers, and the latter appear to be specially dangerous in this respect. Even infected human beings may be a source of danger to healthy animals.

In the present state of our knowledge, it appears to be an impossibility to stamp out the disease in an infected herd. It is not a matter of suppressing abortion,-the principal symptom of the disease,-but of stamping out the infection itself.

After a time no symptoms of the diseaFe are visible. Animals that hale apparently recovered are nevertheless carriers of the organism, and may be a source of infection to man and healthy animals.

Centres of infection should therefore be wiped out, these being all the more dangerous where their existence is not known.

The serum test applied to all suspected animals will give useful informa­tion as to which animals are healthy and which diseased or infective, thus enabling one to separate them from each other.

Animals that fail to pass the test must be considered as a source of danger for a long time, and the only safe measure that can be applied to them appears to be immediate slaughter or to fatten them for the butcher. The herd must be re-stocked with healthy animals, or, better still, with the progeny of infected females. The latter have a certain degree of immunity

R

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ABSTRACTS AND REPORTS.

which is sufficient to protect them against natural infection for a considerable time.

To prevent the spread of the disease rigorous disinfection must be put into force. Bedding and manure should be burned.

The necessary tests should be carried out free of cost or for a nominal sum at laboratories under Government control. It would be well if all animals in an infected district were submitted to the test.

3. The Necessity for Legislation.-The spread of the disease, the possi­bility of spread among the larger domesticated animals, and its transmissi­bility to man, indIcate the necessity of legislative measures for the control of this new plague on the following lines :-

(I) Animals showing symptoms of the disease and reacting to the serum test should be slaughtered forthwith.

(2) Animals reacting without showing any symptoms should be isolated and placed under observation until the disappearance of the agglutinin from the blood. The sale of milk should be forbidden, or controlled in such a manner as to render the milk harmless. The animals should be sold for slaughter under control of the health authorities to prevent infection of the human subject. Entire animals reacting to the serum test but not presenting any clinical symptoms should be castrated and treated as above. It would also be an advantage to compel the production of certificates as to the health of the goats before and during the period of service.

(3) It would be difficult to frame regulations regarding small animals on an infected farm. And besides, these species are far less dangerous than the goat and the sheep to the human subject. However, the isolation and, when possible, the immediate slaughter of these animals should be prescribed.

Infected equidre should be isolated and placed under control of the authorities. The owner should have free use of them, but they should never be allowed to enter any place where they might come into contact with healthy animals.

Should bovines be infected, the cows should be treated in the same manner as sheep and the bulls as horses.

To complete the legislation, the introduction of goats from infected countries should be prohibited, and it should be made illegal to remove herds from infected districts to healthy ones.

Transmission to Man. Methods of Infection.-The resistance offered by man to the disease is far

less than that offered by even the most susceptible animals. I. Natural Infection.-Natural methods of infection are numerous, but

they may be grouped in two classes: infection from the human subject and infection from animal sources, the latter being by far the most common.

(a) Infection from Human Sources.-This method of infection has been the subject of much discussion. Some authors deny tha.t it ever occurs, and others have observed cases in which it has happened. Recent observations tend to show that if infection in this way is rare it is at any rate possible.

Little is known about the factors that may come into play in such a case. The infection may be carried by the excreta of infected persons, and it is possible that sexual relationship may be the means of infection in some cases.

(b) Infectionfrom Animal Sources.-It is some years since the Commission established the fact that the disease in man is almost always of animal origin. It is known that the goat is the chief agent, and that among other animals the sheep is to blame.

Infection by ingestion is the commonest means in man, milk being the most important vehicle. Other foods made from milk (butter, cheese, etc.)

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ABSTRAC1S AND REPORTS.

appear to be also capable of transmitting the infection. Cheese several months old does not appear to be dangerous, but this point needs verification.

Cooked meats are apparently harmless, but the presence of the micrococcus melitensis in the blood and tissues renders raw meat very suspect. No cases of this kind have been proved, but unless precautions are soon taken they are quite likely to occur.

The danger that may arise from vegetables, fruits, etc., contaminated by the excrements of man or animals has been pointed out.

Infection of the human subject by simple contact with diseased animals has been frequently observed. Milking is particularly dangerous in this respect.

The various manipulations involved in the slaughter of infected animals expose man to infection. The infection may also be contracted during shearing of infected sheep.

z. Laboratory Infictton.-Numerous cases have occurred among bacterio­logists.

Prophylaxis.

In the case of the human subject prophylaxis is easy. In view of the fact that the infection is usually of animal origin the best means of protection appears to be to protect the animals from infection. It must be borne in mind that so long as proper regulations regarding animals are not put into force so long will the disease continue to spread among them, thus increasing the risk of the spread of the disease among them. On the other hand, the possibility of contagion from man to man and also from man to animal should lead to the framing of regulations to prevent infection of man and animals from man. These regulations would be without result unless rigorously enforced by public authorities. (Dubois, Rev. Vet., NO.3, March 1911, pp. 129-140; NO·4, April 1911, pp. 199-212; NO.5, May 1911, pp. 261-281.)

THE CAMPAIGN AGAINST BOVINE TUBERCULOSIS IN SWEDEN.

IT has long been felt desirable that a detailed account of the State-supported campaign against bovine tuberculosis in Sweden should be published. The statistical results are not intended as a guide to the control of the disease, nor to give an exhaustive account of the attendant conditions. Their object is simply to give a rapid survey of the extent and results of the campaign in so far as these can be given in the form of statistics. Much valuable informa­tion is to be obtained from accurate accounts of the work in various herds, and anyone who is in doubt as to whether he should fight the disease or not should, with the assistance of the manifold details given, find himself in a position to arrive at a more definite decision. The publication of the result s should settle the debatable point as to whether the campaign against bovine tuberculosis should be more objective than hitherto.

Naturally, it is not possible to review exhaustively the work that is done year by year, and besides, that does not appear to be necessary. The important point is to compare the state of affairs with regard to the disease in each herd at the commencement of the campaign with the state of affairs at the end of the period under consideration, and further, where it appears to be of interest, to discover satisfactory explanations and to learn what con­ditions are favourable or unfavourable. In order to attain this end the