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Active Immunisation Against Foot-and-mouth Disease
ABSTRACTS.
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died in sixty hours. The authors do not indicate how the exact number of spores and bacilli injected was determined. A second guinea-pig was given some of the same filtrate after it had been heated to 75° C. for fifteen minutes, and in this instance the dose administered was "about thirteen spores." Death did not take place in this instance, and the animal was killed by inoculation later. A pellet of fresh f~ces containing anthrax spores placed subcutaneously caused death in thirty-six hours with extreme local <:edema, and a similiar result was obtained when the pellet used had been dried for thirty-two days prior to insertion under the skin. A guinea-pig which had been fed with anthrax spores, and in the f~ces of which spores had been detected, was shaved and scarified on the abdomen, and kept in a jar with its own f~ces. It failed to become infected. Two guinea-pigs were shaved and scarified on the abdomen, and an emulsion of f~ces containing spores was swabbed over the scarified area. Only one died of anthrax. Two other guinea-pigs were treated in a similar way with an emulsion of pellets which had been dried at 37° C. for twenty-four days and afterwards for eight days at 40° to 45° C. Cultures were obtained from the suspension. Neither of the guinea-pigs became infected. With a view to providing an answer to the question as to whether anthrax bacilli can form spores in the alimentary tract of animals, two guinea-pigs were fed by means of gelatin capsules with a few drops of heart blood and of spleen pulp from a guinea-pig just dead of anthrax. Some the heart blood and spleen pulp were used for artificial cultures after they had been heated to 70° to 80° C. for twenty minutes, but no growths were obtained. The f~ces of the guinea-pig fed with spleen pulp contained spores of anthrax on the second day. The same experiment was subsequently performed on the same guinea-pigs, but in neither case were anthrax spores detected in their f~ces. The authors point out that previous experiments made by one of them indicate that the presence of <:edema is not a sure index as to the seat of infection. In these experiments Holman showed that when guinea-pigs or rabbits are killed by inoculation with anthrax on the ear the amount of <:edema is so small that it may escape observation. (" American JI. of Hyg." Vol. IlL, r923, pp. 640-648.)
ACTIVE IMMUNISATION AGAINST FOOT-ANDMOUTH DISEASE. By O. WALDMANN and K. TRANTWEIN. THE authors suggest that there is some resemblance between foot-andmouth disease and small-pox, and that it might be possible to devise a method of protective inoculation against the former on the same lines as the ordinary vaccination against small-pox, that is, by using an attenuated virus which, while not producing the disease, would establish immunity. The idea underlying some of the experiments carried out has been that by passage of the virus through guinea-pigs in series it might be possible to produce such an attenuated virus. The virus maintained in guinea· pigs has from time to time been used for the inoculation of altogether thirty cattle and pigs, but in no case has this result been achieved. Passage of the virus through white rats led to an exaltation of virulence rather than an attenuation. Negative results followed the passage of the" generalised virus" through guinea-pigs because the virus died out. Similar results were obtained when passages were made through passively immunised guinea-pigs. Finally, the plan devised by Cosco and Aguyzi of infectil1g' cattle with virulent blood from guinea-pigs was tried. It was first ascertained that it is
ABSTRACTS.
not possible by either subcutaneous or intravenous inoculation to infect sussceptible cattle with the certainly virulent blood of guinea· pigs infected with foot·and-mouth disease. A number of cattle were injected subcutaneously with doses of infective guinea-pig blood ranging from I to 27 cc. Only two animals reacted, and these showed only a slight rise of temperature. The original idea that the virus became attenuated in the guinea-pigs' blood had to be rejected because it was found that the same blood would infect cattle if used for cutaneous inoculation. The differences in the results are therefore referable to the different methods of inoculation. Thirty animals were used for experiment, and these were first tested as to their susceptibility in the manner described by Waldmann and Pape, that is, by injecting doses of 10 cc. of their serum into infected guinea-pigs without producing any retarding influence on the course of the disease. It has been shown repeatedly that cattle providing such serum are readily infected naturally or experimentally. Blood obtained from a number of infected guinea-pigs twenty-eight to twenty-nine hours after inoculation, at which hour the virus is in greatest concentration in the blood, was defibrinated and used immediately for the inoculation of cattle. Its virulence was established by the inoculation of two guinea-pigs. These inoculations were carried out while the animal's serum was under test to avoid loss of time. As a result of the serum tests thirteen out of the thirty cattle were found to be highly susceptible. The serum of the others exercised in varying degrees a beneficial effect upon the course of the disease in the inoculated guinea-pigs. At intervals of eight to twenty-one days after the inoculation with infective guinea-pig bl03d the thirteen selected animals were subjected to a test inoculation, which consisted in the intracutaneous or intravenous injection of lymph from lesions in pigs in doses ranging from '1 to 5 cc., and in two cases of 10 cc. of guinea-pig blood subcutaneously. The virulence of the lymph was proved on animals used for virus production in the course of serum-making. Further, the animals were kept in contact with severely infected cattle and had the same attendants. In spite of these tests eleven out of the thirteen cattle remained healthy (save that two of them showed elevations of temperature to 39'5° and 39'7° C.). The remaining two animals developed lesions, apparently because the dose of guinea-pig blood was too small, and the authors suggest that the minimum dose should be 5 cc. Emphasis is laid upon the fact that since, in spite of the extreme severity of the test inoculations, the disease was of a mild character in these two animals, a considerable degree of immunity had been conferred on them, and it is suggested that it would have been sufficient to protect against natural infection. The presence of immune bodies in the blood was established by finding that sera, which before the treatment of the animals failed to prevent generalisation in guinea-pigs in doses of 9 or 10 cc., after treatment prevented generalisation in doses of 2 or 3 cc. The serum was therefore almost as protective as that of animals which have recovered from a natural attack of the disease. The experiment with adult cattle suggested that comparable results would be obtained with pigs. but this proved not to be the case. Twentyfour pigs were inoculated subcutaneously or intravenously with doses of virulent guinea-pig blood ranging from '1 to 20 cc. Intravenous inoculation was not practised because it was found to cause severe anaphylactic symptoms in some cases. The results were unsatisfactory, since fourteen of the pigs became affected more or less seriously after an incubation period of three or four days. Nine pigs which did not react to the inoculation with guinea-pig blood contracted the disease when tested by intravenous or intracutaneous inoculation with '5 cc. of lymph from porcine lesions. Only one pig failed to react to both inoculations.
ABSTRACTS. The question as to whether it is possible to immunise calves in this way remains for investigation. (" Archiv f. wissenschaft. u. prakt. Tierheilk," Vol. L., 1923, pp. 229-236.)
SPECIFIC CONTAGIOUS PNEUMONIA IN THE FOAL. A NEW PYOGENIC ORGANISM. By H. MAGNUSSON. PNEUMONIA seldom occurs in foals as a primary condition, being almost always a complication of joint ill. During the year 1922 474 foals were examined by the author and primary pneumonia was found in twenty-seven instances only. In the majority of these cases streptococci and staphylococci were the cause, and in cases of gangrenous pneumonia the bacterial flora was very mixed. In the literature available Magnusson has been able to find only a single reference, by Schmiedhofer, to specific contagious pneumonia of foals, or a disease closely resembling it. In the Hungarian outbreak described by Schmiedhofer there were several cases of purulent pneumonia among foals from one to two months old. Three forms of the disease were recognisable: a peracute, a subacute, and a chronic form. The peracute form was not strictly speaking a pneumonia, for lesions were not found in the lungs, but more of the nature of an acute disease characterised by h
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died in sixty hours. The authors do not indicate how the exact number of spores and bacilli injected was determined. A second guinea-pig was given some of the same filtrate after it had been heated to 75° C. for fifteen minutes, and in this instance the dose administered was "about thirteen spores." Death did not take place in this instance, and the animal was killed by inoculation later. A pellet of fresh f~ces containing anthrax spores placed subcutaneously caused death in thirty-six hours with extreme local <:edema, and a similiar result was obtained when the pellet used had been dried for thirty-two days prior to insertion under the skin. A guinea-pig which had been fed with anthrax spores, and in the f~ces of which spores had been detected, was shaved and scarified on the abdomen, and kept in a jar with its own f~ces. It failed to become infected. Two guinea-pigs were shaved and scarified on the abdomen, and an emulsion of f~ces containing spores was swabbed over the scarified area. Only one died of anthrax. Two other guinea-pigs were treated in a similar way with an emulsion of pellets which had been dried at 37° C. for twenty-four days and afterwards for eight days at 40° to 45° C. Cultures were obtained from the suspension. Neither of the guinea-pigs became infected. With a view to providing an answer to the question as to whether anthrax bacilli can form spores in the alimentary tract of animals, two guinea-pigs were fed by means of gelatin capsules with a few drops of heart blood and of spleen pulp from a guinea-pig just dead of anthrax. Some the heart blood and spleen pulp were used for artificial cultures after they had been heated to 70° to 80° C. for twenty minutes, but no growths were obtained. The f~ces of the guinea-pig fed with spleen pulp contained spores of anthrax on the second day. The same experiment was subsequently performed on the same guinea-pigs, but in neither case were anthrax spores detected in their f~ces. The authors point out that previous experiments made by one of them indicate that the presence of <:edema is not a sure index as to the seat of infection. In these experiments Holman showed that when guinea-pigs or rabbits are killed by inoculation with anthrax on the ear the amount of <:edema is so small that it may escape observation. (" American JI. of Hyg." Vol. IlL, r923, pp. 640-648.)
ACTIVE IMMUNISATION AGAINST FOOT-ANDMOUTH DISEASE. By O. WALDMANN and K. TRANTWEIN. THE authors suggest that there is some resemblance between foot-andmouth disease and small-pox, and that it might be possible to devise a method of protective inoculation against the former on the same lines as the ordinary vaccination against small-pox, that is, by using an attenuated virus which, while not producing the disease, would establish immunity. The idea underlying some of the experiments carried out has been that by passage of the virus through guinea-pigs in series it might be possible to produce such an attenuated virus. The virus maintained in guinea· pigs has from time to time been used for the inoculation of altogether thirty cattle and pigs, but in no case has this result been achieved. Passage of the virus through white rats led to an exaltation of virulence rather than an attenuation. Negative results followed the passage of the" generalised virus" through guinea-pigs because the virus died out. Similar results were obtained when passages were made through passively immunised guinea-pigs. Finally, the plan devised by Cosco and Aguyzi of infectil1g' cattle with virulent blood from guinea-pigs was tried. It was first ascertained that it is
ABSTRACTS.
not possible by either subcutaneous or intravenous inoculation to infect sussceptible cattle with the certainly virulent blood of guinea· pigs infected with foot·and-mouth disease. A number of cattle were injected subcutaneously with doses of infective guinea-pig blood ranging from I to 27 cc. Only two animals reacted, and these showed only a slight rise of temperature. The original idea that the virus became attenuated in the guinea-pigs' blood had to be rejected because it was found that the same blood would infect cattle if used for cutaneous inoculation. The differences in the results are therefore referable to the different methods of inoculation. Thirty animals were used for experiment, and these were first tested as to their susceptibility in the manner described by Waldmann and Pape, that is, by injecting doses of 10 cc. of their serum into infected guinea-pigs without producing any retarding influence on the course of the disease. It has been shown repeatedly that cattle providing such serum are readily infected naturally or experimentally. Blood obtained from a number of infected guinea-pigs twenty-eight to twenty-nine hours after inoculation, at which hour the virus is in greatest concentration in the blood, was defibrinated and used immediately for the inoculation of cattle. Its virulence was established by the inoculation of two guinea-pigs. These inoculations were carried out while the animal's serum was under test to avoid loss of time. As a result of the serum tests thirteen out of the thirty cattle were found to be highly susceptible. The serum of the others exercised in varying degrees a beneficial effect upon the course of the disease in the inoculated guinea-pigs. At intervals of eight to twenty-one days after the inoculation with infective guinea-pig bl03d the thirteen selected animals were subjected to a test inoculation, which consisted in the intracutaneous or intravenous injection of lymph from lesions in pigs in doses ranging from '1 to 5 cc., and in two cases of 10 cc. of guinea-pig blood subcutaneously. The virulence of the lymph was proved on animals used for virus production in the course of serum-making. Further, the animals were kept in contact with severely infected cattle and had the same attendants. In spite of these tests eleven out of the thirteen cattle remained healthy (save that two of them showed elevations of temperature to 39'5° and 39'7° C.). The remaining two animals developed lesions, apparently because the dose of guinea-pig blood was too small, and the authors suggest that the minimum dose should be 5 cc. Emphasis is laid upon the fact that since, in spite of the extreme severity of the test inoculations, the disease was of a mild character in these two animals, a considerable degree of immunity had been conferred on them, and it is suggested that it would have been sufficient to protect against natural infection. The presence of immune bodies in the blood was established by finding that sera, which before the treatment of the animals failed to prevent generalisation in guinea-pigs in doses of 9 or 10 cc., after treatment prevented generalisation in doses of 2 or 3 cc. The serum was therefore almost as protective as that of animals which have recovered from a natural attack of the disease. The experiment with adult cattle suggested that comparable results would be obtained with pigs. but this proved not to be the case. Twentyfour pigs were inoculated subcutaneously or intravenously with doses of virulent guinea-pig blood ranging from '1 to 20 cc. Intravenous inoculation was not practised because it was found to cause severe anaphylactic symptoms in some cases. The results were unsatisfactory, since fourteen of the pigs became affected more or less seriously after an incubation period of three or four days. Nine pigs which did not react to the inoculation with guinea-pig blood contracted the disease when tested by intravenous or intracutaneous inoculation with '5 cc. of lymph from porcine lesions. Only one pig failed to react to both inoculations.
ABSTRACTS. The question as to whether it is possible to immunise calves in this way remains for investigation. (" Archiv f. wissenschaft. u. prakt. Tierheilk," Vol. L., 1923, pp. 229-236.)
SPECIFIC CONTAGIOUS PNEUMONIA IN THE FOAL. A NEW PYOGENIC ORGANISM. By H. MAGNUSSON. PNEUMONIA seldom occurs in foals as a primary condition, being almost always a complication of joint ill. During the year 1922 474 foals were examined by the author and primary pneumonia was found in twenty-seven instances only. In the majority of these cases streptococci and staphylococci were the cause, and in cases of gangrenous pneumonia the bacterial flora was very mixed. In the literature available Magnusson has been able to find only a single reference, by Schmiedhofer, to specific contagious pneumonia of foals, or a disease closely resembling it. In the Hungarian outbreak described by Schmiedhofer there were several cases of purulent pneumonia among foals from one to two months old. Three forms of the disease were recognisable: a peracute, a subacute, and a chronic form. The peracute form was not strictly speaking a pneumonia, for lesions were not found in the lungs, but more of the nature of an acute disease characterised by h