- Email: [email protected]
RECLAIMED RUBBER
586
accumulating physical discomfort of circulatory stagnation due to prolonged standing or sitting. Even then, if the work is interesting and rewarding, it is possible to continue far longer than usual without feeling tired. the
We are left with some idea of the factors which make for fatigue, and with the realisation that we are ignorant of what really happens in the organism and why certain emotions so powerfully inhibit the will to physical or mental activity. Nor do we know whether tiredness is ever beneficial. It may be a warning, or it may be an escape, according to the individual and the circumstances. can
RABIES
THE armchair epidemiologist may like to ponder on a report1 on rabies from the World Health Organisation. During recent years there has been a notable increase in the disease in Europe, Asia, Africa, and America. Almost everywhere the domestic or semidomestic dog is the commonest source of human infection, but the dog in turn gets its infection from a variety of wild animals. In Europe the main vector is the fox: further east it is the wolf and the jackal. In Africa mongooses and members of the weasel family are mostly to blame, while in the U.S.A. foxes in the east and coyotes and skunks in the west are the culprits. Man may, of course, be bitten by any one of these, and there are curious stories of unprovoked attacks by animals which are usually shy and retiring, such as the small spotted skunk or " phobey cat." The disease has been present in the Arctic for many years-but only recently recognised for what it is.2 Human infections there are rare because even a rabid sledge-dog finds Arctic clothing hard to penetrate. As a general rule, an epidemic disease with a high mortality is likely to be self-limiting. Rabies in these wild animals is usually, though not always, fatal; but several attempts to isolate the virus from animals which have recovered have failed. This suggests that the larger carnivores derive their infection from some other animals in which rabies has not yet been identified. It would be a mistake to think that outside these islands rabies is everywhere. It seems rather to spread from more or less permanent reservoirs intermittently. During recent years a wave of infection has been spreading across Europe from the east. In the Federal Republic of Germany evidence of infection has been found in 2660 animals, of which 2071 were foxes. The disease has spread into Denmark, which has been free of it for a long time. It has been known for many years that an increase in the infections in dogs seems to follow an increase in the total numbers of the animals which infect them. A characteristic of some, perhaps all, the carnivores which spread the disease is that their numbers are to a large extent related to the numbers of their customary prey. A plague of voles in the Arctic is soon followed by a bumper year for foxes. Moreover, epidemic rabies in the far north often coincides with a plague of lemmings, but no-one, it seems, has ever recovered the virus from the salivary glands of these little animals. For many years the only animals known to be true carriers of the rabies virus were certain species of vampire bats in Trinidad and the neighbouring parts of South America. Not only do these transmit rabies to the man whose toes stick out from under the blanket, but they also new
Rep. Ser. Wld Hlth Org. 1966, no. 321. Obtainable from H.M. Stationery Office, P.O. Box 569, London, S.E.1. Lassen, H. C. A. Lancet, 1962, i, 247.
1. Tech.
2.
serious losses of cattle, killed by a paralytic form of the disease. The bats can harbour the virus in their salivary glands for at least some months. It was alarming, therefore, to find that this peculiarity was shared by some insectivorous bats in Central America as far north as Texas and Florida. On more than one occasion, one of these usually shy animals has savaged a human.3 More recently the virus has been isolated from insectivorous bats in Turkey and Yugoslavia; if it has not been found nearer home it may be because no-one has looked for it. The surest way of preventing the spread of epidemic rabies is the destruction of stray dogs and the inoculation of the family pets. Preventive inoculation of animals and man now presents no serious difficulty. The wild vectors must be exterminated at the same time or at any rate reduced in numbers: poison, guns, traps, and a bounty to the successful hunter have all been used in Germany and some States of the U.S.A.-a draconian measure which no-one likes. Not everyone who is bitten gets rabies, but anyone in whom the disease develops will surely die. We have many reasons for blessing the English Channel, and not the least of these is our freedom from rabies. An infected dog was introduced by guile in 1918, and it was four years before the disease was eradicated. No-one who has seen a patient with the disease or even undergone prophylactic treatment is likely to support the moves which are made from time to time to abolish our six months’ quarantine. It is not, however, a disease to be entirely forgotten, and in the past few years there have been cases in Britain in patients infected abroad.4 Perhaps, too, someone should look at our bats. The natural distribution of some species suggests that they are in part migratory from continental Europe. If, as some think, the carriage of rabies by insectivorous bats is a new biological phenomenon, it may spread rapidly like measles in a virgin population. Few of us have much to do with bats, but a bat held in the hand can bite very hard indeed. cause
RECLAIMED RUBBER
LAST September we commented5 on the announcement that nearly one million tyres were to be imported from Japan during the ensuing twelve months, and we asked whether it was known that these tyres were free from any anti-oxidant suspected of having carcinogenic properties. This question was raised because it had been statedat an inquest on a rubber worker that the use of reclaimed rubber, if originally compounded with one of the antioxidants known to cause urinary-tract tumours, might be dangerous to the men who worked on the process. A reply to a question in the House of Commons last month stated that " it is very difficult to obtain reliable information as to whether imported rubber articles had contained carcinogenic anti-oxidants and it was reported that the Factory Inspectorate, together with the rubber industry, were going to examine the possibility of developing analytical methods to detect some carcinogenic substances in rubber. Though we welcome the development of such tests, and we hope that both the methods and the results of analysis will be made public, we are at a loss to understand why "
3. Venters, H. D., Hoffert, W. R., Scatterday, J. E.; Hardy, A. V. Am.J. publ. Hlth, 1954, 44, 182. 4. Laughlin. J., Ross, D. J. C. Lancet, 1956, i, 421; Ghosh, F. Brit. med.J. 1964, ii, 167; Ridley, A. ibid. 1965, i, 1596. 5. Lancet, 1965, ii, 627. 6. See ibid. p. 635. 7. Hansard (House of Commons), Feb. 21, 1966, col. 2.
I ’
587
it should be so hard to obtain information about the materials used in articles to be imported. Has no Government
department both the right and the duty to obtain potentially dangerous substances
such information when may be involved ?
service, he implies, is irretrievably committed to searching for defects among children of school age-even although those it finds are already being treated by somebody else. In an age of free medical care, generally good nutrition, and shortage of doctors the search seems hard to justify. Schools
ANACHRONISM AT SCHOOL
WHAT should the school health service be now trying to achieve? Should it be devoting many medical manhours to the routine examination of children, all oj whom have their own family doctor and 85% of whom are found to be healthy ? Horner 1 seems to be among those who suspect that this is so much time and effort wasted; and he seems, too, at a loss to know what to do about it. He set himself to find out-and arrived at a fair notion of what not to do. He has described an experimental questionary which was drawn up as a possible basis for the selection of children for routine medical inspection. Questions were to be answered by the ringing of " yes " or " no ". They were sent to the parents of 853 children eligible for examination at 8 years of age and 637 children eligible at 11 years. Examination was later offered to all the children as usual. The completed questionaries were lent to the examining doctors at the time of the inspection and then returned to Horner for assessment. There, unfortunately, the matter ended. The completed forms were never checked against the results of the inspection, and nothing, therefore, could be concluded about the adequacy of the selection criteria chosen or the accuracy of the parental returns. Of 1490 questionaries circulated, only 63 were not returned; 22 were too incomplete to be of use. Only 1 parent objected in principle. Some wrote at length about problems they wished to discuss-problems which could not always be inferred from the formal replies. 8-10% reported physical symptoms and 4-6% mental symptoms. Questions relating to the latter were the more often unanswered and were perhaps found alien and difficult. Horner decided that a child should be selected for medical examination if the parents requested it or if the questionary was incomplete or not returned. Enuresis was made a cause for selection so that the child could be referred to the service’s enuresis clinic. 418 children (28%) qualified for examination on these grounds. This total was brought to 32% by the inclusion of children whose school progress was said by their parents to be unsatisfactory; and inclusion of all children said to have positive symptoms raised the total to 52%. All these, in practice, would have to be included: where parents have reported even a single symptom subsequent examination can hardly be neglected. 52%, Horner concluded, is too high a proportion. The preliminary selection would not be worth the time and trouble involved. There would be relatively little extra time to give to the examinations which were performed, and defects would almost certainly be missed among the exempted children. As it is, with every child examined, defects go unrecognised; but this Horner sees as no argument for inaccurate selection. Rather, he would have the technique of the inspection improved and better screening tests devised. The school medical 1.
Horner, J. S. Med. Offr, 1966, 115, 29.
are
instruments of education.
The doctor
clearly has a contribution to make in organising health education; and, if a child’s progress or behaviour gives cause for concern, he should clearly be at hand to disany medical causes that may be to blame. The of health conference commended by Didsbury,2 at type which teachers suggest children who might profitably be examined, is one means to this end. At present, however, the doctor can do none of this properly because he is kept too busy with the ritual and perfunctory examination of normal children. cover
LOW BIRTHWEIGHT
IN 1950 the W.H.O. Expert Group on Prematuritya endorsed the international definition and recommended that " an immature infant is a liveborn infant with a birthweight of 51/2 lb. (2500 g.) or less ". Here immaturity and prematurity were taken as synonymous, the aim being to provide special care for infants of low birthweight. Since then it has become accepted that this category has a dual population; and Soderling 4 in 1953 first applied the term " pseudopremature " to distinguish infants born at term who have failed to achieve normal growth in utero from the true premature infant born after a short gestation period. The terminology has since become increasingly confused, but " small for dates " and " low birth-
achieving popularity. investigation into possible causes of unexplained prematurity, Reid5 confirmed that there are two distinct types of low birthweight, and in 1961 W.H.O.6recommended that the concept of prematurity should give way to that of low birthweight. This grouping together of all babies of low birthweight has proved useful in indicating the need for special care in the neonatal period, but it has greatly hampered the emergence of knowledge about aetiology, pathology, neonatal course, subsequent development, and ultimate fate of growth-retarded infants. Such infants account for 34% of births between 38 and 41 weeks, and for 35% of all internationally defined premature births in England, Wales, and Scotland.Further, as Gruenwald 8 points out, no attempt was made by the W.H.O. group to distinguish those.infants who normally have a lower birthweight, as in certain ethnic groups, from those whose low weight is the result of intrauterine deprivation or other causes. Intrauterine retardation of growth was thoroughly reviewed by Warkany et al.,9 and the incidence of liveborn term babies weighing 2500 g. or less was estimated at 1-04% in Los Angeles. 10 More severe retardation and is much less common, but still (2000 g. under) weight In
at
term "
are now
an
accounts
for 8000 infants annuallv in the U.S.A. A high
2. Didsbury, B. Lancet, 1964, i, 101. 3. Tech. Rep. Ser. Wld Hlth Org. 1950, no. 27. 4. Söderling, B. Acta pœdiat., Stockh. 1953, 42, 520. 5. Reid, S. M. J. Obstet. Gynœc. Br. Commonw. 1961, 68, 796. 6. Tech. Rep. Ser. Wld Hlth Org. 1961, no. 217. 7. Butler, N. R., Bonham, D. G. Perinatal Mortality; p. 142. Edinburgh 1963. 8. Gruenwald, P. Biologia Neonat. 1963, 5, 215. 9. Warkany, J., Monroe, B. B., Sutherland, B. S. Am. J. Dis. Child. 1961, 102, 249. 10. McBurney, R. D. Western J. Surg. Obstet. Gynec. 1947, 55, 363.
accumulating physical discomfort of circulatory stagnation due to prolonged standing or sitting. Even then, if the work is interesting and rewarding, it is possible to continue far longer than usual without feeling tired. the
We are left with some idea of the factors which make for fatigue, and with the realisation that we are ignorant of what really happens in the organism and why certain emotions so powerfully inhibit the will to physical or mental activity. Nor do we know whether tiredness is ever beneficial. It may be a warning, or it may be an escape, according to the individual and the circumstances. can
RABIES
THE armchair epidemiologist may like to ponder on a report1 on rabies from the World Health Organisation. During recent years there has been a notable increase in the disease in Europe, Asia, Africa, and America. Almost everywhere the domestic or semidomestic dog is the commonest source of human infection, but the dog in turn gets its infection from a variety of wild animals. In Europe the main vector is the fox: further east it is the wolf and the jackal. In Africa mongooses and members of the weasel family are mostly to blame, while in the U.S.A. foxes in the east and coyotes and skunks in the west are the culprits. Man may, of course, be bitten by any one of these, and there are curious stories of unprovoked attacks by animals which are usually shy and retiring, such as the small spotted skunk or " phobey cat." The disease has been present in the Arctic for many years-but only recently recognised for what it is.2 Human infections there are rare because even a rabid sledge-dog finds Arctic clothing hard to penetrate. As a general rule, an epidemic disease with a high mortality is likely to be self-limiting. Rabies in these wild animals is usually, though not always, fatal; but several attempts to isolate the virus from animals which have recovered have failed. This suggests that the larger carnivores derive their infection from some other animals in which rabies has not yet been identified. It would be a mistake to think that outside these islands rabies is everywhere. It seems rather to spread from more or less permanent reservoirs intermittently. During recent years a wave of infection has been spreading across Europe from the east. In the Federal Republic of Germany evidence of infection has been found in 2660 animals, of which 2071 were foxes. The disease has spread into Denmark, which has been free of it for a long time. It has been known for many years that an increase in the infections in dogs seems to follow an increase in the total numbers of the animals which infect them. A characteristic of some, perhaps all, the carnivores which spread the disease is that their numbers are to a large extent related to the numbers of their customary prey. A plague of voles in the Arctic is soon followed by a bumper year for foxes. Moreover, epidemic rabies in the far north often coincides with a plague of lemmings, but no-one, it seems, has ever recovered the virus from the salivary glands of these little animals. For many years the only animals known to be true carriers of the rabies virus were certain species of vampire bats in Trinidad and the neighbouring parts of South America. Not only do these transmit rabies to the man whose toes stick out from under the blanket, but they also new
Rep. Ser. Wld Hlth Org. 1966, no. 321. Obtainable from H.M. Stationery Office, P.O. Box 569, London, S.E.1. Lassen, H. C. A. Lancet, 1962, i, 247.
1. Tech.
2.
serious losses of cattle, killed by a paralytic form of the disease. The bats can harbour the virus in their salivary glands for at least some months. It was alarming, therefore, to find that this peculiarity was shared by some insectivorous bats in Central America as far north as Texas and Florida. On more than one occasion, one of these usually shy animals has savaged a human.3 More recently the virus has been isolated from insectivorous bats in Turkey and Yugoslavia; if it has not been found nearer home it may be because no-one has looked for it. The surest way of preventing the spread of epidemic rabies is the destruction of stray dogs and the inoculation of the family pets. Preventive inoculation of animals and man now presents no serious difficulty. The wild vectors must be exterminated at the same time or at any rate reduced in numbers: poison, guns, traps, and a bounty to the successful hunter have all been used in Germany and some States of the U.S.A.-a draconian measure which no-one likes. Not everyone who is bitten gets rabies, but anyone in whom the disease develops will surely die. We have many reasons for blessing the English Channel, and not the least of these is our freedom from rabies. An infected dog was introduced by guile in 1918, and it was four years before the disease was eradicated. No-one who has seen a patient with the disease or even undergone prophylactic treatment is likely to support the moves which are made from time to time to abolish our six months’ quarantine. It is not, however, a disease to be entirely forgotten, and in the past few years there have been cases in Britain in patients infected abroad.4 Perhaps, too, someone should look at our bats. The natural distribution of some species suggests that they are in part migratory from continental Europe. If, as some think, the carriage of rabies by insectivorous bats is a new biological phenomenon, it may spread rapidly like measles in a virgin population. Few of us have much to do with bats, but a bat held in the hand can bite very hard indeed. cause
RECLAIMED RUBBER
LAST September we commented5 on the announcement that nearly one million tyres were to be imported from Japan during the ensuing twelve months, and we asked whether it was known that these tyres were free from any anti-oxidant suspected of having carcinogenic properties. This question was raised because it had been statedat an inquest on a rubber worker that the use of reclaimed rubber, if originally compounded with one of the antioxidants known to cause urinary-tract tumours, might be dangerous to the men who worked on the process. A reply to a question in the House of Commons last month stated that " it is very difficult to obtain reliable information as to whether imported rubber articles had contained carcinogenic anti-oxidants and it was reported that the Factory Inspectorate, together with the rubber industry, were going to examine the possibility of developing analytical methods to detect some carcinogenic substances in rubber. Though we welcome the development of such tests, and we hope that both the methods and the results of analysis will be made public, we are at a loss to understand why "
3. Venters, H. D., Hoffert, W. R., Scatterday, J. E.; Hardy, A. V. Am.J. publ. Hlth, 1954, 44, 182. 4. Laughlin. J., Ross, D. J. C. Lancet, 1956, i, 421; Ghosh, F. Brit. med.J. 1964, ii, 167; Ridley, A. ibid. 1965, i, 1596. 5. Lancet, 1965, ii, 627. 6. See ibid. p. 635. 7. Hansard (House of Commons), Feb. 21, 1966, col. 2.
I ’
587
it should be so hard to obtain information about the materials used in articles to be imported. Has no Government
department both the right and the duty to obtain potentially dangerous substances
such information when may be involved ?
service, he implies, is irretrievably committed to searching for defects among children of school age-even although those it finds are already being treated by somebody else. In an age of free medical care, generally good nutrition, and shortage of doctors the search seems hard to justify. Schools
ANACHRONISM AT SCHOOL
WHAT should the school health service be now trying to achieve? Should it be devoting many medical manhours to the routine examination of children, all oj whom have their own family doctor and 85% of whom are found to be healthy ? Horner 1 seems to be among those who suspect that this is so much time and effort wasted; and he seems, too, at a loss to know what to do about it. He set himself to find out-and arrived at a fair notion of what not to do. He has described an experimental questionary which was drawn up as a possible basis for the selection of children for routine medical inspection. Questions were to be answered by the ringing of " yes " or " no ". They were sent to the parents of 853 children eligible for examination at 8 years of age and 637 children eligible at 11 years. Examination was later offered to all the children as usual. The completed questionaries were lent to the examining doctors at the time of the inspection and then returned to Horner for assessment. There, unfortunately, the matter ended. The completed forms were never checked against the results of the inspection, and nothing, therefore, could be concluded about the adequacy of the selection criteria chosen or the accuracy of the parental returns. Of 1490 questionaries circulated, only 63 were not returned; 22 were too incomplete to be of use. Only 1 parent objected in principle. Some wrote at length about problems they wished to discuss-problems which could not always be inferred from the formal replies. 8-10% reported physical symptoms and 4-6% mental symptoms. Questions relating to the latter were the more often unanswered and were perhaps found alien and difficult. Horner decided that a child should be selected for medical examination if the parents requested it or if the questionary was incomplete or not returned. Enuresis was made a cause for selection so that the child could be referred to the service’s enuresis clinic. 418 children (28%) qualified for examination on these grounds. This total was brought to 32% by the inclusion of children whose school progress was said by their parents to be unsatisfactory; and inclusion of all children said to have positive symptoms raised the total to 52%. All these, in practice, would have to be included: where parents have reported even a single symptom subsequent examination can hardly be neglected. 52%, Horner concluded, is too high a proportion. The preliminary selection would not be worth the time and trouble involved. There would be relatively little extra time to give to the examinations which were performed, and defects would almost certainly be missed among the exempted children. As it is, with every child examined, defects go unrecognised; but this Horner sees as no argument for inaccurate selection. Rather, he would have the technique of the inspection improved and better screening tests devised. The school medical 1.
Horner, J. S. Med. Offr, 1966, 115, 29.
are
instruments of education.
The doctor
clearly has a contribution to make in organising health education; and, if a child’s progress or behaviour gives cause for concern, he should clearly be at hand to disany medical causes that may be to blame. The of health conference commended by Didsbury,2 at type which teachers suggest children who might profitably be examined, is one means to this end. At present, however, the doctor can do none of this properly because he is kept too busy with the ritual and perfunctory examination of normal children. cover
LOW BIRTHWEIGHT
IN 1950 the W.H.O. Expert Group on Prematuritya endorsed the international definition and recommended that " an immature infant is a liveborn infant with a birthweight of 51/2 lb. (2500 g.) or less ". Here immaturity and prematurity were taken as synonymous, the aim being to provide special care for infants of low birthweight. Since then it has become accepted that this category has a dual population; and Soderling 4 in 1953 first applied the term " pseudopremature " to distinguish infants born at term who have failed to achieve normal growth in utero from the true premature infant born after a short gestation period. The terminology has since become increasingly confused, but " small for dates " and " low birth-
achieving popularity. investigation into possible causes of unexplained prematurity, Reid5 confirmed that there are two distinct types of low birthweight, and in 1961 W.H.O.6recommended that the concept of prematurity should give way to that of low birthweight. This grouping together of all babies of low birthweight has proved useful in indicating the need for special care in the neonatal period, but it has greatly hampered the emergence of knowledge about aetiology, pathology, neonatal course, subsequent development, and ultimate fate of growth-retarded infants. Such infants account for 34% of births between 38 and 41 weeks, and for 35% of all internationally defined premature births in England, Wales, and Scotland.Further, as Gruenwald 8 points out, no attempt was made by the W.H.O. group to distinguish those.infants who normally have a lower birthweight, as in certain ethnic groups, from those whose low weight is the result of intrauterine deprivation or other causes. Intrauterine retardation of growth was thoroughly reviewed by Warkany et al.,9 and the incidence of liveborn term babies weighing 2500 g. or less was estimated at 1-04% in Los Angeles. 10 More severe retardation and is much less common, but still (2000 g. under) weight In
at
term "
are now
an
accounts
for 8000 infants annuallv in the U.S.A. A high
2. Didsbury, B. Lancet, 1964, i, 101. 3. Tech. Rep. Ser. Wld Hlth Org. 1950, no. 27. 4. Söderling, B. Acta pœdiat., Stockh. 1953, 42, 520. 5. Reid, S. M. J. Obstet. Gynœc. Br. Commonw. 1961, 68, 796. 6. Tech. Rep. Ser. Wld Hlth Org. 1961, no. 217. 7. Butler, N. R., Bonham, D. G. Perinatal Mortality; p. 142. Edinburgh 1963. 8. Gruenwald, P. Biologia Neonat. 1963, 5, 215. 9. Warkany, J., Monroe, B. B., Sutherland, B. S. Am. J. Dis. Child. 1961, 102, 249. 10. McBurney, R. D. Western J. Surg. Obstet. Gynec. 1947, 55, 363.