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NEUTRALISATION OF POLIOMYELITIS VIRUS.
1315
CORRESPONDENCE immunity to the poliomyelitic virus, as indicated by the presence of antivirus, is frequently present in normal people who have been in contact with definite SIR,-In view of the importance of milk in the diet cases of the disease without developing it. They of both children and adults, it is necessary for the quote the work of Anderson and Frost (1911) who, known facts regarding the safety of this article of in seven normal individuals (employed as controls food to be placed before consumers and all concerned. in investigating the serum of cases of poliomyelitis), It is widely acknowledged that the average found complete neutralisation in one case and partial consumption of milk in this country could be greatly neutralisation in two cases. Will you permit me to draw attention to my increased to the benefit of the public health and the in collaboration with C. Kling on the of national A researches the substantial physique. improvement increase, however, cannot be anticipated until public Swedish epidemic in 1912. We studied the serum of opinion demands the highest standards and practice nine normal individuals, of whom seven were close contacts with cases of poliomyelitis and two, children of milk production and distribution. In this country an effort has been made to improve of 14 months and 2 years of age respectively, had the milk-supply by means of a grading system and, never suffered from poliomyelitis or been in contact notwithstanding a certain measure of confusion that with cases. In the first series there was complete has arisen from the excessive number of grades, neutralisation in two cases, partial neutralisation it is still fundamentally true that the ideal milk (lengthened incubation period in the monkeys supply would be that which would conform to the inoculated) in four cases, and no neutralisation in one highest grade defined by the Ministry of Health, case. In the second series there was almost complete neutralisation (incubation period of 32 days) in one namely, " Certified milk." In practice, however, it is found that only a very case and no neutralisation in the other. Thus the small proportion of the public are able to afford this serum of certain healthy individuals, most of whom grade, even for the feeding of infants, and the same were living in an infected area and-so far as could be position, in varying degrees, applies to the other judged from clinical manifestations-showed an grades that lie between it and pasteurised milk, immunity to the virus, neutralised completely the which is the form of milk commonly distributed in virus of poliomyelitis in the proportion of almost a great centres of population. Experience has shown third, and partially in the proportion of 5 : 9. We that where pasteurisation (the heating of milk under concluded that microbicidal properties which totally conditions which ensure the destruction of harmful or partially neutralise the virus of infantile paralysis bacteria, yet leave the vitamins unimpaired) is are present in the serum of individuals who have been generally practised, infection traceable to milk living in intimate contact with cases of poliomyelitis recedes almost to vanishing point. This fact has without developing the disease. Their immunity PASTEURISATION OF MILK. To the Editor of THE LANCET.
led the
fewer than 21 cities in the U.S.A. to ordain compulsory pasteurisation of milk.
could therefore be attributed to the presence of these microbicidal substances in the blood. Wealso The signatories, while expressing no opinion on stated our opinion that the immunity was due to latent the principle of compulsion, are emphatically agreed infections, the organism reacting to the virus only by that the time has arrived when, in order to increase the production of antibodies, or, in some instances milk consumption and diminish the risk of milk the immunity followed the abortive form of the disease infection, pasteurisation should be universally that had not been diagnosed as such. These results explain the unequal receptivity of recognised as the immediate practical method of ensuring safety. They record their satisfaction at human subjects to the virus of poliomyelitis during the fact that about 90 per cent. of the London supply the course of epidemics. is pasteurised with markedly beneficial results. I am, Sir, yours faithfully,’Dr. C. LEVADITI, They are of opinion that the first step in educating Professeur à l’Institut Pasteur. the public to demand pasteurised milk should be the Paris, Dec. 2nd, 1930. simplification of the present milk grading system and the clear labelling of pasteurised milk as such. They are further of opinion that while no effort should be PREVENTION OF SCARLET FEVER IN SCHOOLS. relaxed to improve milk at the source, the entire To the Editor of THE LANCET. milk-supply-excepting " Certified milk "-should SIR,-May I be permitted to add to my first letter be pasteurised. in view of Dr. Glover and Dr. Griffith’s communicaWe are, Sir, yours faithfully, tion. The object I had in mind was, as I stated, to DAWSON OF PENN. H. CHARLES CAMERON. correct the impression which their paper inevitably THOMAS HORDER. CHARLES PORTER. created-viz., that nothing could be done to stop JOHN ROBERTSON. JAMES FENTON. an epidemic of scarlet fever in a school. Their ROBERT HUTCHISON. JOHN MACMILLAN. statement was that passive immunity is too evanescent A. BOSTOCK HILL. for use in a boarding school, that it has the disDec. 9th, 1930. advantage to sensitise to serum (we have now fortunately Dr. Dunn’s account of the use of this NEUTRALISATION OF POLIOMYELITIS VIRUS. method by him at Uppingham, a boarding school, for the last three years with complete success, upon To the Editor of THE LANCET. which I wish to him), and that the SIR,-In an article published in your issue of production of activecongratulate the Dick method immunity by Oct. 25th (p. 895) Dr. R. W. Fairorother and Dr. took too and was too uncertain ; these pronouncelong W. G. Scott Brown record the results of experiments ments, coupled with their admission that the ordinary on the action of the serum of various individuals 1 on the virus of poliomyelitis. Annales de l’Institut Pasteur, 1913, xxvii., 839. They conclude that no
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CORRESPONDENCE immunity to the poliomyelitic virus, as indicated by the presence of antivirus, is frequently present in normal people who have been in contact with definite SIR,-In view of the importance of milk in the diet cases of the disease without developing it. They of both children and adults, it is necessary for the quote the work of Anderson and Frost (1911) who, known facts regarding the safety of this article of in seven normal individuals (employed as controls food to be placed before consumers and all concerned. in investigating the serum of cases of poliomyelitis), It is widely acknowledged that the average found complete neutralisation in one case and partial consumption of milk in this country could be greatly neutralisation in two cases. Will you permit me to draw attention to my increased to the benefit of the public health and the in collaboration with C. Kling on the of national A researches the substantial physique. improvement increase, however, cannot be anticipated until public Swedish epidemic in 1912. We studied the serum of opinion demands the highest standards and practice nine normal individuals, of whom seven were close contacts with cases of poliomyelitis and two, children of milk production and distribution. In this country an effort has been made to improve of 14 months and 2 years of age respectively, had the milk-supply by means of a grading system and, never suffered from poliomyelitis or been in contact notwithstanding a certain measure of confusion that with cases. In the first series there was complete has arisen from the excessive number of grades, neutralisation in two cases, partial neutralisation it is still fundamentally true that the ideal milk (lengthened incubation period in the monkeys supply would be that which would conform to the inoculated) in four cases, and no neutralisation in one highest grade defined by the Ministry of Health, case. In the second series there was almost complete neutralisation (incubation period of 32 days) in one namely, " Certified milk." In practice, however, it is found that only a very case and no neutralisation in the other. Thus the small proportion of the public are able to afford this serum of certain healthy individuals, most of whom grade, even for the feeding of infants, and the same were living in an infected area and-so far as could be position, in varying degrees, applies to the other judged from clinical manifestations-showed an grades that lie between it and pasteurised milk, immunity to the virus, neutralised completely the which is the form of milk commonly distributed in virus of poliomyelitis in the proportion of almost a great centres of population. Experience has shown third, and partially in the proportion of 5 : 9. We that where pasteurisation (the heating of milk under concluded that microbicidal properties which totally conditions which ensure the destruction of harmful or partially neutralise the virus of infantile paralysis bacteria, yet leave the vitamins unimpaired) is are present in the serum of individuals who have been generally practised, infection traceable to milk living in intimate contact with cases of poliomyelitis recedes almost to vanishing point. This fact has without developing the disease. Their immunity PASTEURISATION OF MILK. To the Editor of THE LANCET.
led the
fewer than 21 cities in the U.S.A. to ordain compulsory pasteurisation of milk.
could therefore be attributed to the presence of these microbicidal substances in the blood. Wealso The signatories, while expressing no opinion on stated our opinion that the immunity was due to latent the principle of compulsion, are emphatically agreed infections, the organism reacting to the virus only by that the time has arrived when, in order to increase the production of antibodies, or, in some instances milk consumption and diminish the risk of milk the immunity followed the abortive form of the disease infection, pasteurisation should be universally that had not been diagnosed as such. These results explain the unequal receptivity of recognised as the immediate practical method of ensuring safety. They record their satisfaction at human subjects to the virus of poliomyelitis during the fact that about 90 per cent. of the London supply the course of epidemics. is pasteurised with markedly beneficial results. I am, Sir, yours faithfully,’Dr. C. LEVADITI, They are of opinion that the first step in educating Professeur à l’Institut Pasteur. the public to demand pasteurised milk should be the Paris, Dec. 2nd, 1930. simplification of the present milk grading system and the clear labelling of pasteurised milk as such. They are further of opinion that while no effort should be PREVENTION OF SCARLET FEVER IN SCHOOLS. relaxed to improve milk at the source, the entire To the Editor of THE LANCET. milk-supply-excepting " Certified milk "-should SIR,-May I be permitted to add to my first letter be pasteurised. in view of Dr. Glover and Dr. Griffith’s communicaWe are, Sir, yours faithfully, tion. The object I had in mind was, as I stated, to DAWSON OF PENN. H. CHARLES CAMERON. correct the impression which their paper inevitably THOMAS HORDER. CHARLES PORTER. created-viz., that nothing could be done to stop JOHN ROBERTSON. JAMES FENTON. an epidemic of scarlet fever in a school. Their ROBERT HUTCHISON. JOHN MACMILLAN. statement was that passive immunity is too evanescent A. BOSTOCK HILL. for use in a boarding school, that it has the disDec. 9th, 1930. advantage to sensitise to serum (we have now fortunately Dr. Dunn’s account of the use of this NEUTRALISATION OF POLIOMYELITIS VIRUS. method by him at Uppingham, a boarding school, for the last three years with complete success, upon To the Editor of THE LANCET. which I wish to him), and that the SIR,-In an article published in your issue of production of activecongratulate the Dick method immunity by Oct. 25th (p. 895) Dr. R. W. Fairorother and Dr. took too and was too uncertain ; these pronouncelong W. G. Scott Brown record the results of experiments ments, coupled with their admission that the ordinary on the action of the serum of various individuals 1 on the virus of poliomyelitis. Annales de l’Institut Pasteur, 1913, xxvii., 839. They conclude that no
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