The normal habitat of Cl. tetani is the intestinal tract of "horses, cows and other herbivora. The bacilli are sometimes found in human faces. Heavily manured soil is particularly liable to be contaminated with the highly resistant spores of this angerobe. Introduced through a punctured wound commonly made by a splinter or nail, the bacilli or spores—particularly in the presence of pyogenic infection, laceration of tissues or a foreign body—tend to multiply and produce the powerful toxin which acts on the nervous system.
Although the potential risk of tetanus following deep wounds is well recognized, the very real danger of infection following superficial septic abrasions in children or mild septic skin lesions in farm workers is not sufficiently appreciated. Imperfectly sterilized catgut has been responsible for the development of post-operative tetanus.
Early diagnosis is very important. Stiffness of the jaw, pain in the neck or back increased by manipulation and associated with the characteristic facial expression should lead to immediate specific treatment.
Tetanus is not a notifiable disease. The length of the incubation period varies greatly and the duration from the onset of symptoms until the appearance of definite spasms has a very important bearing on prognosis. An incubation period of less than seven days indicates a severe case. When the prodromal period is less than twenty-four hours a fatal outcome is almost invariable.
Preventive Treatment.—Passive immunization is an effective measure, but it must be understood that the method has its limitations. First, it must be carried out at the time of injury. Delay is dangerous. Secondly, passive immunization only lasts for two to three weeks, so that the patient could emerge from his temporary cover before the incubation period had elapsed, though by this time florid tetanus would be unlikely to develop. Thirdly, and most important, persons who have previously received horse serum in some form may develop serum sickness; such persons are liable to eliminate the antitoxin more rapidly, thus reducing the period of " cover ". To these factors must be added the doctor's natural reluctance to administer antitoxin when a wound is apparently trivial—yet such wounds may be infected by tetanus.
In view of these considerations, two alternatives may now be considered. If the patient is seen at the time of wounding it may be assumed that the formation of tetanus toxin has not started. After the wound has been thoroughly opened and cleansed prophylactic tetracycline is given for one week. A dose of ro g. per day will suffice. Antitoxin is not administered. On the other hand, if some time has elapsed between the wounding and the patient being seen by the doctor, antitoxin is imperative as a first step. A dose of 1,500 units intramuscularly is given. At the same time active immunization with ro ml. of adsorbed tetanus toxoid is begun.Such ideal alternatives do not allow for the fact that more than half of the cases'of tetanus occur as a result of trivial wounds which never called for medical supervision. To some extent this might imply the success of passive immunization. The most important aspect of the argument, however, is that it underlines the need for active immunization. If this is given first in infancy in the form of triple vaccine, repeated at 18 months and again at school entry (when only diphtheria and tetanus toxoids need be given) the risk of tetanus is reduced to a minimum. In such persons the correct treatment, when wounding occurs years later, is the administration of a booster injection of ro ml. of tetanus toxoid.
Finally, when a first injection of toxoid is given at the time of wounding (as part of the active-passive immunization) all necessary steps should be taken to ensure that the family doctor is informed so that he may complete the course with a second injection six weeks later.
Curative Treatment.—The management of a case of tetanus is nearly always a complex problem. Although there can be no accepted routine, satisfactory7 treatment will generally involve four main considerations.
The spasms are, of course, the result of the specific effect of tetanus toxin, so that its neutralization seems an obvious and immediate concern. It must be realized, however, that by the time the diagnosis is established much of the toxin is " fixed " and is beyond the reach of antitoxin. But since toxin is still being formed by the bacilli in the tissues it is essential to obtain the advantage of passive immunization as quickly as possible, and in order to achieve this a dose of 20,000 units is adequate. After an initial intramuscular injection of half the dose the remainder should be given intravenously. (Before proceeding with the injection of serum the details on p. 50 should be consulted.) It should be remembered that when the patient develops a serum reaction (either immediate or delayed), the excretion of antitoxin is hastened. If this should occur, repeated doses of 1,500 units of antitoxin intramuscularly should be given every second or third day. It must be appreciated that antitoxin is given more to promote passive immunization than for curative purposes.
In many cases there is an indication of the causative wound. Often this will have closed or there may be evidence of deep ramifications into the tissues to produce conditions which encourage an anasrobic situation. Whenever possible, the wound should be excised and freely opened and the opportunity taken to ensure the removal of any necrotic tissue or foreign material. The wound should then be left open, although every attempt must be made to prevent any further bacterial infection. Large doses of penicillin (i to a mega units per day) should be given parenterally.
The next problem is to secure adequate sedation of the patient. It is always desirable to set up at once an intravenous drip in order to ensure adequate hydration and, at least to begin with, 5 per cent. glucose in saline will prove sufficient. The drip tube can be used for the intravenous administration of sedatives. Thiopentone (0-5 to i g.) may be added to each pint (600 ml.) in the drip bottle, and this will serve for continuous basal sedation. A syringe containing o-i to 0-3 g. of thiopentone is retained at hand and this can be injected into the drip tube when there is need for nursing or medical attention or to cover very severe spasms. In the more severe cases when sedation has to be prolonged there is a possible danger of toxic reaction to a build-up of thiopentone and, for this reason, it should be reserved for the early stages only when the patient is being assessed and wound toilet being carried out. Some recent—and apparently severe—cases have been managed very satisfactorily with chlorpromazine or promazine given intramuscularly. These drugs can be given in divided doses to a total daily amount of up to 2-0 g. without apparent toxic effect, and in some cases it has proved possible to stop the thiopentone and depend upon the promazine alone. A syringe containing thiopentone should remain at hand, however, to control the more severe spasms. Should thiopentone or a promazine derivative or a combination of them prove insufficient, it will be necessary to resort to muscle relaxants. Since the principles involved are those of modern anaesthetic practice, it will be obvious that the management of this aspect of the problem demands that an anassthetist should be consulted at once in the early stages. It then becomes possible to proceed step by step from the simplest to the most complicated methods.
With the degree of sedation necessary to secure freedom from spasm, the maintenance of a clear airway becomes the next problem. In all but the mildest cases an elective tracheostomy should be performed and a cuffed endotracheal tube inserted. This ensures that the risk of anoxia from laryngeal spasm is eliminated, or at least greatly reduced, and avoids secretions passing from the pharynx downwards. Tracheostomy alone is of great value in the more effective control of the patient who is moderately to severely ill; it is, of course, essential when the need arises for muscle relaxants for it then becomes simple to change over to mechanical respiration.
Enough has been said to emphasize the point that the treatment of tetanus is a very elaborate procedure. There is no doubt that the institution of such specialized methods has greatly improved the prognosis even in the most severe cases. The progress to recovery of such cases makes it necessary to point out certain features of tetanus that were previously not observed. First, during the acute stage, periods of pyrexia—indeed hyperpyrexia—are sometimes seen. This is best managed by leaving the patient uncovered and by the use of fans. Secondly, it seems likely that late toxic effects on other organs of the body— notably the heart—may be encountered. Convalescence should, therefore, not be hastened. Finally, it should be realized that the patient who has recovered from tetanus is not necessarily immune. Since his occupation may expose him to further risk it is important, when the stage of complete recovery is reached, to proceed with a programme of active immunization with toxoid.
General Management.—The patient should lie on a sponge-rubber mattress with the bedclothes supported by a cradle. Isolation is not essential. Trained day and night nurses are necessary. Noise must be excluded, the sickroom darkened and nursing duties performed quietly and preferably at times when the patient is deeply under sedatives.
A minimum daily food intake of 2,000 calories in an adult patient is a highly important part of the treatment, but it is very difficult to attain. One of the main duties of the nurse is to feed the patient who is only mildly affected at hourly or even half-hourly intervals with milk, egg flip, thin gruels and glucose lemonade. In severe cases feeding should be carried out through a nasal tube left in position or supplemented by the intravenous administration of 5 per cent. glucose saline by the drip method. The use of a composite food such as Corn-plan (Glaxo) makes the calculation of caloric intake simple and tube feeding by mouth is given greater precision.The bowels should be moved by enemata, and retention of urine watched for and relieved by catheterization.
Wednesday, July 30, 2008
SMALLPOX (Variola)
Two distinct varieties of smallpox are recognized—variola major and variola minor. The latter was at one time endemic in certain parts of the country; the former is always imported from abroad. Clinically the two types can be similar, but whereas the death rate of major smallpox is around 15 per cent., that of minor smallpox rarely exceeds 0-2 per cent. The minor form is due to a smallpox virus of low virulence and the disease breeds true. Vaccination is equally protective against both forms of the disease.
The virus of smallpox almost certainly enters the body via the respiratory tract. During the course of the infection, virus is discharged in the secretions of the mouth and nose and from the skin lesions. Bed linen is thus heavily infected and the air of the room becomes charged with the virus. Although infection is most often from case to case, papers, clothing, etc., may all act as vehicles, for the virus appears capable of survival for long periods in the dry state. As a result, not only must the isolation of the case be complete but there must be the most stringent disinfection of all clothing and other articles in the sickroom.
Smallpox is a notifiable disease. The incubation period is usually 12 days, but may vary between 10 and 14 days.
Prevention.—The control of smallpox is essentially a public health problem. The accurate diagnosis of the initial case or cases rests, however, with the practitioner, and herein lies a grave responsibility. Early diagnosis, followed by prompt isolation of the primary case, the immediate vaccination and continued supervision of all contacts, and thorough disinfection of the patient's house and its contents are the essentials of successful smallpox control. The practitioner should not hesitate, therefore, to confer with an experienced, consultant regarding any patient who in his opinion might possibly be suffering from smallpox. The misdiagnosis of the initial case or cases as chickenpox has been the starting-point of almost every recent smallpox epidemic in Great Britain.
There can be no doubt as to the wisdom of promptly removing every case of variola major to hospital. During an epidemic of variola minor hospital isolation is desirable so long as accommodation is available. In the event of continued spread of the minor form, circumstances may justify or necessitate home treatment. These matters of policy are for the local Medical Officer of Health to decide, but when a case of variola minor is treated at home, isolation of the patient should be strictly enforced and every member of the household vaccinated.
After the removal of the patient to hospital every known contact should be traced as quickly as possible and subjected to vaccination or revaccination. When possible close contacts such as members of the same household should be isolated either in their own home or in suitable isolation units so that they may be more closely observed. Adult contacts, once they have been vaccinated, may continue their occupations but should be kept under daily surveillance. Intimate contacts who have never been vaccinated are especially at risk. Such persons will, of course, be vaccinated at once but should, in addition, be given a subcutaneous injection of 1-5 to 2-0 g. of hyperimmunegammaglobulm (prepared from persons recently vaccinated against smallpox).
Chemoprophylaxis.—The most significant contribution to the control of smallpox epidemics would be the discovery of a chemical which prevented multiplication of the virus in the cell, for the time of contact is usually known and the incubation period is relatively long. For this reason, therefore, much attention was directed to the use of N-methylisatin /5-thiosemicarbazone (Mar-boran) on a very large scale in India with this prophylactic intention. The results were favourable but so far only a single report of its application is available. Unfortunately the drug proved very toxic in some British trials and further work is, therefore, required before it can be recommended for general use.
Vaccination.—In this highly effective method of prophylaxis against smallpox, introduced by Jenner in 1798, vaccinia, or cowpox, is inoculated into the human subject. Vaccinia is now regarded as a disease attributable to variola virus modified as a result of its passage through animals.
The National Health Service Acts in Great Britain have abolished compulsory vaccination in infancy. It is, however, recommended that vaccination should be part of the programme for child immunization and carried out after the age of one year. Contraindications to this general recommendation are : failure to thrive, the presence of septic skin conditions, chronic eczematous or other manifestations of an allergic nature, the suspicion of hypogammaglobulinaemia or the fact that the individual is receiving corticosteroid preparations.
Fresh glycerinated lymph, which is issued in sealed capillary tubes, should be employed. The lymph should be stored in a refrigerator. The contents of a tube, once unsealed, must not be kept for use on a future occasion. The lymph must be expelled from the tube by a rubber teat—such as that used on an infant's feeding-bottle ; the mouth must not be applied directly to the tube.
The usual site for vaccination is over the insertion of the left deltoid muscle, but for assthetic and other reasons the inner and posterior aspect of the arm or the outer aspect of the thigh or leg may be chosen. The skin should be cleansed with soap and warm water, wiped with ether and dried carefully. The multiple-pressure method is recommended. To perform the operation a drop of lymph is first expelled on to the cleansed area. With the side of the tip of a sterile pin or needle firm pressures are made through the drop of lymph on to the underlying skin ; the pressure exerted should be sufficient to mark the skin, but not to draw blood. For a primary vaccination 10 to 12 pressures are adequate ; for revaccination 20 to 30 should be made. Excess lymph may be blotted off immediately and no dressing is necessary. This method has the advantage that it produces a minimal amount of trauma and therefore of local reaction and subsequent scarring. It probably does not give such a long-lasting immunity as the older scratch method, but since smallpox is no longer an endemic disease, the protection it affords is sufficient for most of the people in this country. When the maximum degree of protection against smallpox is desirable (in smallpox contacts), the number of insertions should be increased to two, situated at least i in. apart and the " scratch " technique used.The duration of immunity to smallpox after primary vaccination by the multiple pressure method is variable. Good " takes " to revaccination may be obtained even after the lapse of only one year. A distinction must be drawn between the results of primary vaccination and revaccination. In the former the resulting lesion does not reach a maximum until about the eighth day ; in the latter the maximum evolution is reached on the third to fifth day. This more rapid response to revaccination is one of the arguments for continuing the practice of primary vaccination in early childhood. If such a person is exposed he will respond to revaccination in the early part of the incubation period and thus be more likely to escape the illness.
Both of these reactions indicate that the individual was susceptible to small pox andhas now been rendered immune. There is a dangerous tendency in revaccination to regard no reaction or slight local reactions which reach a maximum in 24 to 48 hours as proof of immunity. Such an interpretation is unacceptable, for there may be three other explanations. First, the vaccination may have been unsatisfactorily performed ; second, the lymph may be inert; and third, the individual may be reacting merely to trauma or to the vaccine lymph. The last may be excluded fairly easily by carrying out a control vaccination with heated lymph. The others can only be excluded by performing the vaccination at least three times ; at the last insertion an entirely different site should be chosen. Such pertinacity is unnecessary in childhood. It is essential if the person is travelling to a country where smallpox is likely to be encountered and when an International Certificate of Vaccination is required.
In the event of exposure to smallpox, vaccination should immediately be performed unless there is reliable evidence of successful primary vaccination within the previous three years or successful revaccination within the previous five years. The important words in the last sentence are " reliable " and " successful ". In case of doubt, revaccinate. Owing to the risk of vaccinial encephalitis, slight as it may be, primary vaccination should not be performed in adolescents unless they have been directly exposed to smallpox ; exceptions to this general rule are nurses and medical students—for the possibility of unsuspected contact in such persons is always present.
Successful vaccination within the first four days of the incubation period may prevent an attack of smallpox.
Curative Treatment.—There is no specific treatment for smallpox. The constitutional disturbance of the prodromal stage is treated on the lines already laid down (p. i). The diet at this stage is limited to fluids, and water must be administered freely.
No chemotherapeutic substance at present available has been found to influence the maturation of the rash of smallpox from the maculo-papular to the vesicular stage, even when treatment is begun in the pre-eruptive phase. The thiosemicarbazone derivatives have not been therapeutically effective. The administration of antibiotics in adequate dosage may, however, be helpful in diminishing the amount of pus formation. The classical secondary fever caused by absorption of bacterial toxins may thus be reduced and scarring diminished. On the other hand, the patient with severe confluent smallpox goes steadily downhill—despite intensive chemotherapy—and may show evidence of increasing toxasmia, presumably due more to the absorption of tissue breakdown products and widespread destruction of the epidermis than to any bacterial effects.
General Management.—During the papular and vesicular stages of the eruption the regular application of an antiseptic dusting powder (boric talc dusting powder, B.P.C.) or calamine lotion (B.P.) will help to allay the skin irritation. In variola minor such treatment will usually suffice, for in this form the rash often aborts, secondary fever is usually absent and the prognosis is uniformly good.
Iced compresses applied to the face and distal parts of the limbs, and frequently changed, will be found comforting in the confluent eruption of major smallpox. Prolonged warm baths, spraying with a i : 40 solution of phenol or smearing the skin with petroleum jelly with 3 per cent. phenol are alternative methods of treatment. In children the arms may require to be splinted or the hands bandaged to prevent scratching. Chloral hydrate given orally may give some relief and facilitate sleep ; morphine aggravates skin irritation.
When the pocks begin to rupture, the patient, if not too ill, should be given a daily bath containing potassium permanganate. The offensive smell associated with confluent cases of major smallpox can be masked to some extent by sprinkling eucalyptus oil on and around the bed. The application of starch or linseed poultices spread thinly on lint will hasten the separation of the scabs, and subsequent tenderness of the skin can be alleviated by the application of sterile talcum powder or zinc oxide ointment. The virus is suceptible to the action of potassium permanganate, so that painting the lesions with a i per cent. aqueous solution is effective against both bacterial invaders and the virus. Contar^ination of the ward air is thus diminished.
Owing to the presence of the eruption on the mucous membranes, the eyes, mouth, throat, nose and larynx require careful treatment. Drops of 20 per cent. sulphacetamide solution should be instilled into the eyes four-hourly. Simple ointment applied to the margins prevents the lids from sticking together during sleep. The mouth and throat must be cleansed at regular intervals ; either a i : 5,000 solution of potassium permanganate or peroxide of hydrogen diluted with two parts of water may be employed as a spray or mouth-wash. Frequent inhalations of steam, impregnated with Friar's balsam or creosote, help to alleviate laryngeal and bronchial symptoms. Dysphagia may be lessened by sucking fragments of ice or an amethocaine lozenge before each feed.
The fluid diet of the prodromal period requires to be supplemented by soft solids during the eruptive stage. Fresh fruit juice drinks sweetened with glucose must be administered freely throughout the illness.
Complications.—Severe laryngitis sometimes necessitates tracheostomy. Bronchopneumonia is a common and frequently fatal complication. Keratitis and panophthalmitis are liable to occur in severe cases, particularly if the eyes have not been carefully treated from the beginning. Myocardial damage is frequently present and strict bed rest must be enforced throughout. Hasmor-rhage, especially from the uterus, is fairly common in female patients with smallpox, and may necessitate transfusion with blood or plasma.
Convalescence.—The patient should be kept in bed until the eruption has crusted and isolation must be continued until the last crust has separated from the skin. This period varies from three weeks in mild cases to three months or longer in severe attacks. Detachment of the crusts can be hastened by warm baths and the application of starch poultices, olive oil or simple ointment. The thick skin of the palms and soles may be softened by frequent soaking in hot water, and the buried crusts picked out with a sterile scalpel. A thorough soap-and-water bath and shampoo precedes the transfer of the patient to a non-infected room in which he puts on clean clothes.
In variola minor and in mild attacks of major smallpox convalescence is usually rapid and the patient is fit for discharge from hospital or isolation as soon as he is free from infection. He may return to school or business in two to four weeks after release from isolation, but after severe attacks, several months may elapse before the patient is able to resume his normal activities.
The virus of smallpox almost certainly enters the body via the respiratory tract. During the course of the infection, virus is discharged in the secretions of the mouth and nose and from the skin lesions. Bed linen is thus heavily infected and the air of the room becomes charged with the virus. Although infection is most often from case to case, papers, clothing, etc., may all act as vehicles, for the virus appears capable of survival for long periods in the dry state. As a result, not only must the isolation of the case be complete but there must be the most stringent disinfection of all clothing and other articles in the sickroom.
Smallpox is a notifiable disease. The incubation period is usually 12 days, but may vary between 10 and 14 days.
Prevention.—The control of smallpox is essentially a public health problem. The accurate diagnosis of the initial case or cases rests, however, with the practitioner, and herein lies a grave responsibility. Early diagnosis, followed by prompt isolation of the primary case, the immediate vaccination and continued supervision of all contacts, and thorough disinfection of the patient's house and its contents are the essentials of successful smallpox control. The practitioner should not hesitate, therefore, to confer with an experienced, consultant regarding any patient who in his opinion might possibly be suffering from smallpox. The misdiagnosis of the initial case or cases as chickenpox has been the starting-point of almost every recent smallpox epidemic in Great Britain.
There can be no doubt as to the wisdom of promptly removing every case of variola major to hospital. During an epidemic of variola minor hospital isolation is desirable so long as accommodation is available. In the event of continued spread of the minor form, circumstances may justify or necessitate home treatment. These matters of policy are for the local Medical Officer of Health to decide, but when a case of variola minor is treated at home, isolation of the patient should be strictly enforced and every member of the household vaccinated.
After the removal of the patient to hospital every known contact should be traced as quickly as possible and subjected to vaccination or revaccination. When possible close contacts such as members of the same household should be isolated either in their own home or in suitable isolation units so that they may be more closely observed. Adult contacts, once they have been vaccinated, may continue their occupations but should be kept under daily surveillance. Intimate contacts who have never been vaccinated are especially at risk. Such persons will, of course, be vaccinated at once but should, in addition, be given a subcutaneous injection of 1-5 to 2-0 g. of hyperimmunegammaglobulm (prepared from persons recently vaccinated against smallpox).
Chemoprophylaxis.—The most significant contribution to the control of smallpox epidemics would be the discovery of a chemical which prevented multiplication of the virus in the cell, for the time of contact is usually known and the incubation period is relatively long. For this reason, therefore, much attention was directed to the use of N-methylisatin /5-thiosemicarbazone (Mar-boran) on a very large scale in India with this prophylactic intention. The results were favourable but so far only a single report of its application is available. Unfortunately the drug proved very toxic in some British trials and further work is, therefore, required before it can be recommended for general use.
Vaccination.—In this highly effective method of prophylaxis against smallpox, introduced by Jenner in 1798, vaccinia, or cowpox, is inoculated into the human subject. Vaccinia is now regarded as a disease attributable to variola virus modified as a result of its passage through animals.
The National Health Service Acts in Great Britain have abolished compulsory vaccination in infancy. It is, however, recommended that vaccination should be part of the programme for child immunization and carried out after the age of one year. Contraindications to this general recommendation are : failure to thrive, the presence of septic skin conditions, chronic eczematous or other manifestations of an allergic nature, the suspicion of hypogammaglobulinaemia or the fact that the individual is receiving corticosteroid preparations.
Fresh glycerinated lymph, which is issued in sealed capillary tubes, should be employed. The lymph should be stored in a refrigerator. The contents of a tube, once unsealed, must not be kept for use on a future occasion. The lymph must be expelled from the tube by a rubber teat—such as that used on an infant's feeding-bottle ; the mouth must not be applied directly to the tube.
The usual site for vaccination is over the insertion of the left deltoid muscle, but for assthetic and other reasons the inner and posterior aspect of the arm or the outer aspect of the thigh or leg may be chosen. The skin should be cleansed with soap and warm water, wiped with ether and dried carefully. The multiple-pressure method is recommended. To perform the operation a drop of lymph is first expelled on to the cleansed area. With the side of the tip of a sterile pin or needle firm pressures are made through the drop of lymph on to the underlying skin ; the pressure exerted should be sufficient to mark the skin, but not to draw blood. For a primary vaccination 10 to 12 pressures are adequate ; for revaccination 20 to 30 should be made. Excess lymph may be blotted off immediately and no dressing is necessary. This method has the advantage that it produces a minimal amount of trauma and therefore of local reaction and subsequent scarring. It probably does not give such a long-lasting immunity as the older scratch method, but since smallpox is no longer an endemic disease, the protection it affords is sufficient for most of the people in this country. When the maximum degree of protection against smallpox is desirable (in smallpox contacts), the number of insertions should be increased to two, situated at least i in. apart and the " scratch " technique used.The duration of immunity to smallpox after primary vaccination by the multiple pressure method is variable. Good " takes " to revaccination may be obtained even after the lapse of only one year. A distinction must be drawn between the results of primary vaccination and revaccination. In the former the resulting lesion does not reach a maximum until about the eighth day ; in the latter the maximum evolution is reached on the third to fifth day. This more rapid response to revaccination is one of the arguments for continuing the practice of primary vaccination in early childhood. If such a person is exposed he will respond to revaccination in the early part of the incubation period and thus be more likely to escape the illness.
Both of these reactions indicate that the individual was susceptible to small pox andhas now been rendered immune. There is a dangerous tendency in revaccination to regard no reaction or slight local reactions which reach a maximum in 24 to 48 hours as proof of immunity. Such an interpretation is unacceptable, for there may be three other explanations. First, the vaccination may have been unsatisfactorily performed ; second, the lymph may be inert; and third, the individual may be reacting merely to trauma or to the vaccine lymph. The last may be excluded fairly easily by carrying out a control vaccination with heated lymph. The others can only be excluded by performing the vaccination at least three times ; at the last insertion an entirely different site should be chosen. Such pertinacity is unnecessary in childhood. It is essential if the person is travelling to a country where smallpox is likely to be encountered and when an International Certificate of Vaccination is required.
In the event of exposure to smallpox, vaccination should immediately be performed unless there is reliable evidence of successful primary vaccination within the previous three years or successful revaccination within the previous five years. The important words in the last sentence are " reliable " and " successful ". In case of doubt, revaccinate. Owing to the risk of vaccinial encephalitis, slight as it may be, primary vaccination should not be performed in adolescents unless they have been directly exposed to smallpox ; exceptions to this general rule are nurses and medical students—for the possibility of unsuspected contact in such persons is always present.
Successful vaccination within the first four days of the incubation period may prevent an attack of smallpox.
Curative Treatment.—There is no specific treatment for smallpox. The constitutional disturbance of the prodromal stage is treated on the lines already laid down (p. i). The diet at this stage is limited to fluids, and water must be administered freely.
No chemotherapeutic substance at present available has been found to influence the maturation of the rash of smallpox from the maculo-papular to the vesicular stage, even when treatment is begun in the pre-eruptive phase. The thiosemicarbazone derivatives have not been therapeutically effective. The administration of antibiotics in adequate dosage may, however, be helpful in diminishing the amount of pus formation. The classical secondary fever caused by absorption of bacterial toxins may thus be reduced and scarring diminished. On the other hand, the patient with severe confluent smallpox goes steadily downhill—despite intensive chemotherapy—and may show evidence of increasing toxasmia, presumably due more to the absorption of tissue breakdown products and widespread destruction of the epidermis than to any bacterial effects.
General Management.—During the papular and vesicular stages of the eruption the regular application of an antiseptic dusting powder (boric talc dusting powder, B.P.C.) or calamine lotion (B.P.) will help to allay the skin irritation. In variola minor such treatment will usually suffice, for in this form the rash often aborts, secondary fever is usually absent and the prognosis is uniformly good.
Iced compresses applied to the face and distal parts of the limbs, and frequently changed, will be found comforting in the confluent eruption of major smallpox. Prolonged warm baths, spraying with a i : 40 solution of phenol or smearing the skin with petroleum jelly with 3 per cent. phenol are alternative methods of treatment. In children the arms may require to be splinted or the hands bandaged to prevent scratching. Chloral hydrate given orally may give some relief and facilitate sleep ; morphine aggravates skin irritation.
When the pocks begin to rupture, the patient, if not too ill, should be given a daily bath containing potassium permanganate. The offensive smell associated with confluent cases of major smallpox can be masked to some extent by sprinkling eucalyptus oil on and around the bed. The application of starch or linseed poultices spread thinly on lint will hasten the separation of the scabs, and subsequent tenderness of the skin can be alleviated by the application of sterile talcum powder or zinc oxide ointment. The virus is suceptible to the action of potassium permanganate, so that painting the lesions with a i per cent. aqueous solution is effective against both bacterial invaders and the virus. Contar^ination of the ward air is thus diminished.
Owing to the presence of the eruption on the mucous membranes, the eyes, mouth, throat, nose and larynx require careful treatment. Drops of 20 per cent. sulphacetamide solution should be instilled into the eyes four-hourly. Simple ointment applied to the margins prevents the lids from sticking together during sleep. The mouth and throat must be cleansed at regular intervals ; either a i : 5,000 solution of potassium permanganate or peroxide of hydrogen diluted with two parts of water may be employed as a spray or mouth-wash. Frequent inhalations of steam, impregnated with Friar's balsam or creosote, help to alleviate laryngeal and bronchial symptoms. Dysphagia may be lessened by sucking fragments of ice or an amethocaine lozenge before each feed.
The fluid diet of the prodromal period requires to be supplemented by soft solids during the eruptive stage. Fresh fruit juice drinks sweetened with glucose must be administered freely throughout the illness.
Complications.—Severe laryngitis sometimes necessitates tracheostomy. Bronchopneumonia is a common and frequently fatal complication. Keratitis and panophthalmitis are liable to occur in severe cases, particularly if the eyes have not been carefully treated from the beginning. Myocardial damage is frequently present and strict bed rest must be enforced throughout. Hasmor-rhage, especially from the uterus, is fairly common in female patients with smallpox, and may necessitate transfusion with blood or plasma.
Convalescence.—The patient should be kept in bed until the eruption has crusted and isolation must be continued until the last crust has separated from the skin. This period varies from three weeks in mild cases to three months or longer in severe attacks. Detachment of the crusts can be hastened by warm baths and the application of starch poultices, olive oil or simple ointment. The thick skin of the palms and soles may be softened by frequent soaking in hot water, and the buried crusts picked out with a sterile scalpel. A thorough soap-and-water bath and shampoo precedes the transfer of the patient to a non-infected room in which he puts on clean clothes.
In variola minor and in mild attacks of major smallpox convalescence is usually rapid and the patient is fit for discharge from hospital or isolation as soon as he is free from infection. He may return to school or business in two to four weeks after release from isolation, but after severe attacks, several months may elapse before the patient is able to resume his normal activities.
SCARLET FEVER
Scarlet fever results from infection (usually of the throat) with Sir. pyogenes. It occurs only if the streptococcus produces the specific toxin in the host and if the host is susceptible to that toxin. The typical rash (and perhaps some of the other signs) is produced by this toxin, which is, therefore, often referred to as the erythrogenic toxin. Since there may be wide differences both in the toxigenicity and in the host-susceptibility, there is great variation in the severity of the clinical syndrome. Many mild cases occur which are liable to be missed and spread the infection. People who have become immune to the toxin are not immune to streptococcal infection. When they are infected, a streptococcal tonsillitis may occur, and such persons, perhaps even more than carriers, play an important part in the spread of the disease and render control virtually impossible.
Although infection very commonly occurs through the medium of the " missed case ", the contamination of animate or inanimate materials by streptococcal discharges is also of importance. Infected milk is a common cause of epidemics. In hospital wards, the dust may contain streptococci, and measures to reduce dust form an important aspect of control. After recovery, cases of both scarlet fever and tonsillitis which have not been specifically treated may continue to carry streptococci in the throat or nose. Nurses (especially mid-wives), teachers and individuals associated with the supply of milk should be subjected to detailed bacteriological examination after recovery from the infection and before return to work.
Scarlet fever has a short incubation period—-from two to five days—and is a notifiable disease.
Prevention and Control.—The Dick Test and Immunization.—A skin test, analogous to the Schick test, can indicate the capacity of the individual to deal with the erythrogenic toxin. It now has no more than historic interest, for, of course, it gives no indication of the individual's susceptibility to streptococcal infection. Control, by means of penicillin, of all forms of attack by Sir. pyogenes, is so complete that it is undesirable to commend the further use of the test, or the need to invoke an antitoxic immunity', whether active (by the injection of increasing doses of toxin) or passive (by the use in therapy of a specific antitoxin).
Penicillin.—Systemic penicillin will clear streptococci from the throat and in ward outbreaks in hospital the spread of the organism is limited by this treatment. In such conditions, with the patient under control, administration of oral phenoxymethylpenicillin for seven days usually suffices to break the chain of infection. Tetracycline-resistant strains of Str. pyogenes have been isolated recently. The bacteriologist should therefore examine all strains to exclude bizarre examples of resistance.
Gmeral Measures.—The patient must be promptly and effectively isolated. Children who are contacts should be excluded from school for one week. When the patient is treated at home—as he should be—some local health authorities still insist on the remaining susceptible children of the household being kept away from school throughout the entire period of treatment—an action completely unjustifiable on our knowledge of the spread of the disease and the rapid reduction of infectivity obtained with penicillin treatment.
A quarantine period of at least one week must be strictly enforced in the case of'adult contacts whose occupation entails the handling of milk or other foods or close contact with children. Such persons can be rendered free from infection by giving penicillin in full therapeutic doses. Cultures of throat and nose one week later are almost invariably found to be negative.
If an epidemic of streptococcal infection is to be stamped out in a residential school or institution, a knowledge of the type of Str. pyogenes responsible is valuable, so that cases of hsemolytic streptococcal tonsillo-pharyngitis and carriers of the specific organism may be isolated. Bacteriological assistance is obviously very important.
Curative Treatment —Chemotherapy—Pemci\\m therapy rapidly eliminates Str pyogenes from the throat and nose, and this has two important results. It renders the patient rapidly non-infective and it lessens the risk of complications —particularly rheumatic fever. Oral therapy with phenoxymethylpemcillm is practical but" if streptococcal infection of the tonsils is to be eliminated, must be continued'for at least seven days. A single intramuscular injection of 30o>o°o to ooo ooo units of benzathine penicillin—according to age—is an effective wav of ensuring that the patient receives adequate penicillin coverage over the whole period of his illness. Unfortunately the injection is rather painful When the initial illness is severe, treatment should be started with four-hourly intramuscular injections of benzylpenicillin ; as clinical improvement occurs treatment can be terminated with a single injection of benzathine penicillin, ihe important point in the administration of penicillin is that it must continue for seven days if the infection is to be adequately suppressed. When stopped too soon relapse is likely to occur. Indeed, a possible disadvantage of the use ot penicillin is its interference with the development of immunity.
Serum Treatment—The effectiveness of penicillin is such that the administration of antitoxin is now unnecessary.
Complications.—Otitis media, nephritis, arthritis, adenitis and rhinitis are complications, for the treatment of which the reader is referred to appropriate sections of this book. Nephritis is now recognized to be associated with infection by a few special types of Str. pyogenes— particularly type 12. Ihe complication therefore tends to occur in certain epidemics only. Acute rheumatism, on the other hand, may occur after infection by any of the serological types Penicillin therapy reduces to a minimum all of these complications which may, of course, be encountered after apparently mild infections. This is a strong argument for treating all cases with penicillin.
Convalescence.—Providing the condition of the myocardium and the pulse is satisfactory, patients with uncomplicated scarlet fever may be allowed out of bed on the seventh day of disease, and in suitable weather into the open air three days later. The treatment of the complicated case in no way differs from that advised elsewhere for the particular complication.
carriersThe mere presence of Str. pyogenes in the fauces or nose cannot be regarded as a reliable index of infectivity. Nevertheless, a rich growth of this . organism from either the throat or nose of certain persons, e.g. dairy workers, nurses, medical men, school-teachers, may reasonably be regarded as an indication for continued isolation until the carrier condition has ceased. A course of systemic benzylpenicillin in doses of 0-5 mega units per day for 7 days is usually effective, but bacteriological confirmation is, of course, essential. If this fails, surgical appraisal of the condition of the nasopharynx should be advised. Antiseptic applications to the fauces and pharynx are worthless.
Although infection very commonly occurs through the medium of the " missed case ", the contamination of animate or inanimate materials by streptococcal discharges is also of importance. Infected milk is a common cause of epidemics. In hospital wards, the dust may contain streptococci, and measures to reduce dust form an important aspect of control. After recovery, cases of both scarlet fever and tonsillitis which have not been specifically treated may continue to carry streptococci in the throat or nose. Nurses (especially mid-wives), teachers and individuals associated with the supply of milk should be subjected to detailed bacteriological examination after recovery from the infection and before return to work.
Scarlet fever has a short incubation period—-from two to five days—and is a notifiable disease.
Prevention and Control.—The Dick Test and Immunization.—A skin test, analogous to the Schick test, can indicate the capacity of the individual to deal with the erythrogenic toxin. It now has no more than historic interest, for, of course, it gives no indication of the individual's susceptibility to streptococcal infection. Control, by means of penicillin, of all forms of attack by Sir. pyogenes, is so complete that it is undesirable to commend the further use of the test, or the need to invoke an antitoxic immunity', whether active (by the injection of increasing doses of toxin) or passive (by the use in therapy of a specific antitoxin).
Penicillin.—Systemic penicillin will clear streptococci from the throat and in ward outbreaks in hospital the spread of the organism is limited by this treatment. In such conditions, with the patient under control, administration of oral phenoxymethylpenicillin for seven days usually suffices to break the chain of infection. Tetracycline-resistant strains of Str. pyogenes have been isolated recently. The bacteriologist should therefore examine all strains to exclude bizarre examples of resistance.
Gmeral Measures.—The patient must be promptly and effectively isolated. Children who are contacts should be excluded from school for one week. When the patient is treated at home—as he should be—some local health authorities still insist on the remaining susceptible children of the household being kept away from school throughout the entire period of treatment—an action completely unjustifiable on our knowledge of the spread of the disease and the rapid reduction of infectivity obtained with penicillin treatment.
A quarantine period of at least one week must be strictly enforced in the case of'adult contacts whose occupation entails the handling of milk or other foods or close contact with children. Such persons can be rendered free from infection by giving penicillin in full therapeutic doses. Cultures of throat and nose one week later are almost invariably found to be negative.
If an epidemic of streptococcal infection is to be stamped out in a residential school or institution, a knowledge of the type of Str. pyogenes responsible is valuable, so that cases of hsemolytic streptococcal tonsillo-pharyngitis and carriers of the specific organism may be isolated. Bacteriological assistance is obviously very important.
Curative Treatment —Chemotherapy—Pemci\\m therapy rapidly eliminates Str pyogenes from the throat and nose, and this has two important results. It renders the patient rapidly non-infective and it lessens the risk of complications —particularly rheumatic fever. Oral therapy with phenoxymethylpemcillm is practical but" if streptococcal infection of the tonsils is to be eliminated, must be continued'for at least seven days. A single intramuscular injection of 30o>o°o to ooo ooo units of benzathine penicillin—according to age—is an effective wav of ensuring that the patient receives adequate penicillin coverage over the whole period of his illness. Unfortunately the injection is rather painful When the initial illness is severe, treatment should be started with four-hourly intramuscular injections of benzylpenicillin ; as clinical improvement occurs treatment can be terminated with a single injection of benzathine penicillin, ihe important point in the administration of penicillin is that it must continue for seven days if the infection is to be adequately suppressed. When stopped too soon relapse is likely to occur. Indeed, a possible disadvantage of the use ot penicillin is its interference with the development of immunity.
Serum Treatment—The effectiveness of penicillin is such that the administration of antitoxin is now unnecessary.
Complications.—Otitis media, nephritis, arthritis, adenitis and rhinitis are complications, for the treatment of which the reader is referred to appropriate sections of this book. Nephritis is now recognized to be associated with infection by a few special types of Str. pyogenes— particularly type 12. Ihe complication therefore tends to occur in certain epidemics only. Acute rheumatism, on the other hand, may occur after infection by any of the serological types Penicillin therapy reduces to a minimum all of these complications which may, of course, be encountered after apparently mild infections. This is a strong argument for treating all cases with penicillin.
Convalescence.—Providing the condition of the myocardium and the pulse is satisfactory, patients with uncomplicated scarlet fever may be allowed out of bed on the seventh day of disease, and in suitable weather into the open air three days later. The treatment of the complicated case in no way differs from that advised elsewhere for the particular complication.
carriersThe mere presence of Str. pyogenes in the fauces or nose cannot be regarded as a reliable index of infectivity. Nevertheless, a rich growth of this . organism from either the throat or nose of certain persons, e.g. dairy workers, nurses, medical men, school-teachers, may reasonably be regarded as an indication for continued isolation until the carrier condition has ceased. A course of systemic benzylpenicillin in doses of 0-5 mega units per day for 7 days is usually effective, but bacteriological confirmation is, of course, essential. If this fails, surgical appraisal of the condition of the nasopharynx should be advised. Antiseptic applications to the fauces and pharynx are worthless.
RUBELLA (German Measles)
Rubella is a virus infection, spread by direct contact and possibly by fomites. There is no information available regarding the conveyance of infection by carriers. Infectivity appears to be limited to the prodromal and early eruptive stages of the illness.
Rubella is not a notifiable disease. The incubation period is usually from 14 to 18 days, but may vary from 13 to 21 days.
Preventive Treatment.—Rubella in the first three to four months of pregnancy may cause changes in the foetus and the baby may be born with congenital defects. The common abnormalities reported have been congenital cataracts, deafness and cardiac defects. Such infants may continue to excrete virus for some weeks after birth and constitute an unsuspected source of infection of contacts. This important fact must completely alter our outlook on this trivial disease. There is need to review the traditional measures in regard to quarantine, for, especially in girls, there is now every reason for encouraging infection in childhood. Unfortunately, it is hard to interfere with established practice and school authorities are slow to adopt this new principle. When a woman in the early months of pregnancy is exposed to the disease sero-prevention should be practised. Gamma-globulin has been prepared from rubella convalescents and may be obtained from Blood Transfusion Centres. If not available, ordinary gamma-globulin is a satisfactory substitute, but must be given in high dosage, since rubella is not an infection which all adults have experienced. A dose of 10 to 15 ml. is desirable (which represents two to three ampoules of the usual material).
Curative Treatment.—Treatment is purely symptomatic. The patient should remain in bed until the temperature has subsided and the rash faded. The illness is usually so mild that the patient can be kept on an ordinary diet and no special treatment is required. Although complications are uncommon, attention should be drawn to the frequency of polyarthritis in adults. This often involves the small joints of the hands and feet and can be most disabling for two to three weeks. Complete recovery is invariable.
Rubella is not a notifiable disease. The incubation period is usually from 14 to 18 days, but may vary from 13 to 21 days.
Preventive Treatment.—Rubella in the first three to four months of pregnancy may cause changes in the foetus and the baby may be born with congenital defects. The common abnormalities reported have been congenital cataracts, deafness and cardiac defects. Such infants may continue to excrete virus for some weeks after birth and constitute an unsuspected source of infection of contacts. This important fact must completely alter our outlook on this trivial disease. There is need to review the traditional measures in regard to quarantine, for, especially in girls, there is now every reason for encouraging infection in childhood. Unfortunately, it is hard to interfere with established practice and school authorities are slow to adopt this new principle. When a woman in the early months of pregnancy is exposed to the disease sero-prevention should be practised. Gamma-globulin has been prepared from rubella convalescents and may be obtained from Blood Transfusion Centres. If not available, ordinary gamma-globulin is a satisfactory substitute, but must be given in high dosage, since rubella is not an infection which all adults have experienced. A dose of 10 to 15 ml. is desirable (which represents two to three ampoules of the usual material).
Curative Treatment.—Treatment is purely symptomatic. The patient should remain in bed until the temperature has subsided and the rash faded. The illness is usually so mild that the patient can be kept on an ordinary diet and no special treatment is required. Although complications are uncommon, attention should be drawn to the frequency of polyarthritis in adults. This often involves the small joints of the hands and feet and can be most disabling for two to three weeks. Complete recovery is invariable.
ORNITHOSIS (Psittacosis)
Human infection with the viruses of ornithosis usually arises through contact with diseased parrots, budgerigars or other members of the parrot family, but the disease may also be contracted from infected canaries, pigeons, finches, or fulmar petrels. The virus is excreted in the bird's droppings, and the portal of infection in man is probably the respiratory tract. Human case-to-case infection has been suspected but not proven.
An acute febrile illness with combined typhoidal and pneumonic symptoms occurring in a person who is closely associated with parrots, pigeons, etc., is probably ornithosis. The diagnosis can be confirmed most easily by the demonstration of a rising titre of antibodies in the blood Ornithosis is not a notifiable disease. The duration of the incubation period is uncertain, but may be seven days or longer.
Prevention and Control.—The control of the importation of birds of the parrot family has not eliminated the disease. Many indigenous birds and, in recent years, pigeons have been the most important single source of human infection. The handling and petting of even apparently healthy domestic birds is the usual means of infection and the possession of such pets may be an important clue pointing to the clinical diagnosis.
Curative Treatment.—Tetracycline is rapidly effective against infection with the ornithosis group of viruses. The dose is 2 g. daily, given by mouth at six- to eight-hour intervals, reduced to i g. daily as the clinical condition improves.
Although isolation need not be enforced, it is probably wise to regard the patient as potentially infective. Sputum, urine and stools should be disinfected.
An acute febrile illness with combined typhoidal and pneumonic symptoms occurring in a person who is closely associated with parrots, pigeons, etc., is probably ornithosis. The diagnosis can be confirmed most easily by the demonstration of a rising titre of antibodies in the blood Ornithosis is not a notifiable disease. The duration of the incubation period is uncertain, but may be seven days or longer.
Prevention and Control.—The control of the importation of birds of the parrot family has not eliminated the disease. Many indigenous birds and, in recent years, pigeons have been the most important single source of human infection. The handling and petting of even apparently healthy domestic birds is the usual means of infection and the possession of such pets may be an important clue pointing to the clinical diagnosis.
Curative Treatment.—Tetracycline is rapidly effective against infection with the ornithosis group of viruses. The dose is 2 g. daily, given by mouth at six- to eight-hour intervals, reduced to i g. daily as the clinical condition improves.
Although isolation need not be enforced, it is probably wise to regard the patient as potentially infective. Sputum, urine and stools should be disinfected.
POLIOMYELITIS (Infantile Paralysis)
Although paralytic poliomyelitis (the " major " illness) is the overt form of illness following infection with the specific virus, it is produced in a minority of those infected. In a far greater proportion there is either no manifestation of illness or there is a disturbance of varying clinical severity unaccompanied by paralysis. There is no doubt that in some of these " minor " illnesses the virus actually reaches the central nervous system but the illness aborts without subsequent paralysis. That a considerable amount of unrecognized infection occurs in the community can now be demonstrated by the virologist who is able to show the presence of serum antibodies (a sound index of past infection) in a high proportion of the adult population—often, indeed, in people who are unaware of having encountered the infection.
The virus enters the body by the mouth, multiplies in the cells of the intestinal mucosa, and is excreted in the faeces. The central nervous system is reached by way of the blood stream so that virasmia precedes the onset of clinical evidence of involvement of nerve cells. The infectivity varies greatly, but it would appear that the fsecal excretion of virus is greatest in the most severe cases. Virus is present in the stool of all paralytic cases, the excretion slowly waning over a period of eight to ten weeks. In about half the patients, stool cultures become negative in three to four weeks.Poliomyelitis is a notifiable disease. There are three serological types of poliomyelitis virus, of which Types i and 2 seem to be the more frequent epidemic producers. The incubation period probably varies widely although in most cases it lies between seven and ten days Prevention and Epidemiological Control.—Specific Prophylaxis.—The known presence of antibody in the serum of many adults encouraged the use of gamma-globulin to confer a temporary passive immunity and thus to prevent the disease in contacts along lines exactly similar to those which proved successful in measles. Although theoretically sound, it is not a practicable method of control and its use is not advocated.
Two varieties of polio vaccine are available:
(1) The first (Salk-type) consists of formalin-killed viruses of the three antigenic types. This material is injected intramuscularly or sub-cutaneously in doses of i -o ml. The first two injections are given with an interval of four weeks ; a third dose after a period of six months is an essential part of the immunization programme and, indeed, it is desirable to give a fourth injection a year or two later. The vaccines which are now available have undergone careful safety tests ; they contain an increased quantity of antigen, and are very effective in inducing a measurable humoral immunity. The widespread use of Salk-type vaccine has been responsible for a sharp decline in the incidence of poliomyelitis in the United States and Britain.
(2) The second (Sabin-type) vaccine consists of live attenuated polioviruses. It may be obtained in monotypic form (most commonly used in North America) or in tri-typic form (mainly used in this country). This vaccine is easily administered : the dose is dropped on a lump of sugar or similar vehicle which is then taken by mouth. The live virus infects the cells of the gastro-intestinal tract so that it is excreted in the stool for a considerable time after administration. Subsequently antibodies can be demonstrated in the serum.Appraisal of the Two Vaccines.—Both vaccines, in their present form, offer satisfactory immunity. With the killed virus vaccine this immunity is purely a humoral one so that, although poliovirus is prevented from reaching the central nervous system, intestinal infection can still occur. This can constitute a disadvantage to the older contacts of vaccinated children since unsuspected infection of the vaccinated might enhance the exposure of the unvaccinated. Further, with the passage of time, immunity might be expected to wane in the older person, who would, however, be less inclined to present himself for " booster " injections. Finally, there is the slight inconvenience involved in its intramuscular injection.
The live attenuated virus vaccine is free from most of these disadvantages. The simplicity of its administration has meant that large townships have been immunized in a carefully organized, one-day programme. In the face of a rising incidence of the disease this could permit the application of the vaccine very rapidly—preferably using a monotypic vaccine of a type not causing the epidemic —and indeed this method would seem to have been successful in halting the progress of an epidemic. It may be that in such conditions an " interference phenomenon " comes into plav; the bowel cells become infected with the " tamed " strain and prevent the " wild " virus from successfully colonizing them.
The fear of " antigenic shift "—the mutation of low virulence to higher virulence strains during intestinal passage—would not, in the event, seem to have been of practical significance. There is some evidence that minor antigenic change occurs but, having regard to the very large populations that have been successfully vaccinated, there has been no indication of harmful effect. Some cases of paralysis have occurred in vaccinated subjects, usually in adults, which could possibly be attributed to the administered virus. Such events, however, have been of the order of one in several millions vaccinated and absolute proof that the vaccine virus was responsible has often been lacking.
There probably exists a place for both vaccines. If the '' quadruple vaccine " (diphtheria, tetanus, pertussis and killed poliovirus combined) could be produced free from side-effects, there would be much to be said in its favour. It would, however, be unlikely to contribute to the eradication of the disease. There is ground for believing that a really intensive world-wide campaign, using the live attenuated vaccine, would be likely to interfere seriously with the natural history of the virulent poliovirus. The vaccine of choice, therefore, is that of the live attenuated form—preferably administered on a widespread scale during the non-polio season of the year.
General Measures.—By the time that a diagnosis of paralytic poliomyelitis is made it may be assumed that infection has been well distributed among the immediate contacts. This makes effective control very difficult. There is, however, agreement that the patient must be promptly and effectively isolated and this is best done by admission to an infectious diseases hospital. Children who have been in contact with the patient should be kept under strict medical surveillance for a period of three weeks from the date of last contact. Adult contacts may continue their occupation providing it does not entail mixing with children, as in the case of nurses and school-teachers. They should, however, abstain from all social activities for three weeks from the date of last contact; kissing or playing with. young children must be strictly forbidden.
Any form of strenuous activity should be avoided. A contact who suffers from a febrile illness or who complains of any symptoms suggestive of an abortive attack of poliomyelitis should be strictly isolated until recovery ensues. Bed rest should be insisted on for a period of at least one week. During epidemics the practitioner should advise mothers to ensure that children are not over-active and that they secure adequate rest. A short period of enforced rest immediately after the midday meal is a sensible measure.
It is now accepted that certain factors provoke and determine the nature of the predominant paralysis. For example, tonsillectomy may be followed by a severe form of bulbar infection. During periods of prevalence operations on the nose and throat should not be undertaken. Intramuscular injections may be followed by considerable local reaction and this has been associated with paralysis in the limb used for the injection. Alum-containing vaccines have been especially incriminated and for this reason immunization programmes are often temporarily suspended during periods of increased prevalence. This risk should be eliminated by ensuring that polio vaccination is carried out early in life and immunity maintained by " booster " doses. Pregnancy renders women more vulnerable to infection by poliomyelitis, and therefore in the care of the expectant mother immunization with killed vaccine is desirable. Finally excessive muscular activity during the period when the person is infected with the virus may contribute to the development of severe paralysis. Hence, during periods of increased poliomyelitis prevalence additional caution is justified in the treatment of any unexplained febrile illnesses, for these may be in fact minor reactions to polio virus infection. After recovery from such illnesses energetic sports should be forbidden for a week or two.
Curative Treatment.—Serum Treatment.—Neither convalescent serum nor gamma-globulin has effect upon the course of poliomyelitis, for by the time a diagnosis has been made the virus is in the nerve cells and beyond the reach of antibody.
General Management.—The " Minor " Illness.—It is easy to seem over-fearful of poliomyelitis, but there is no doubt that few infections rouse such strong emotional reactions in parents. Since the symptoms of the minor illness are vague and non-specific—fever, headache, vomiting or nausea, pain in the back, stiffness of the neck, drowsiness or irritability with, in the more severe forms, muscular pains or weakness—the condition will only be recognized when there is either a history of contact with a case of paralytic illness or when the disease is known to be present in the district. In such circumstances it is wise to adopt caution in dealing with minor febrile illnesses and to counsel complete rest. It seems possible that strict bed rest in such cases may minimize, though it will not always completely prevent, subsequent paralysis.
The " Major " Illness.—This may be suspected when there is extreme irritability, muscle tenderness or pain or obvious paralysis. Spinal and neck stiffness is usual in these cases : hence the patient either cannot sit up, or when he does so cannot bend forward to make the chin touch the knees. Unnecessarily " finicky " examinations should be avoided ; careful observation will permit accurate diagnosis and the full assessment of paralysis can await the disappearance of muscle pain and tenderness. This pain and tenderness can be most commanding and may be relieved by continuous hot flannel packs. The affected limbs should be placed in a position of rest by means of properly placed pillows and sandbags and by the use of a " cage " to take the weight of bedclothes. When the patient is being treated outside of hospital, the advice of an ortho-pasdic surgeon should be immediately obtained.
When the shoulder-girdle muscles are involved, the possibility of interference with respiratory efficiency must always be kept in mind. Careful examination to exclude diaphragmatic paralysis must be made. The patient should be asked to count from one upwards to see how far he can get with a single breath. The test can be frequently repeated and forms a useful gauge of diminishing respiratory control. It is important to differentiate between respiratory insufficiency due to lack of muscle power in diaphragm and inter-costals from that due to obstruction of the airways by mucoid secretions from loss of the power of swallowing. These latter cases—the true " bulbar " forms— often present as respiratory infections or pneumonia, and their early recognition is of great importance. Here the immediate need is the establishment of adequate drainage, which is best obtained in the prone position with the foot of the bed raised. Suction of the pharyngeal secretions must be frequently carried out and every care taken to ensure a clear airway. Contrary to the common belief, these purely bulbar cases, when properly managed, will usually recover; the patient who is in greatest danger is the one in whom there is a combination of spinal and bulbar involvement, when the most skilled medical and nursing care is essential. All preparations must be made to maintain respiration (p. 688).
When all muscle tenderness has disappeared, simple splints (e.g. Cramer wire) should be applied under the guidance of an orthopsedic surgeon, who should, in fact, be called upon to assist in the supervision of the patient from the onset of paralysis. The limb should never be encased in plaster but should lie in plaster " shells " or padded Cramer wire splints made to the individual's requirements so that daily gentle massage and passive movements of the affected limbs may be supplemented by the local application of hot packs. There is a good deal to be said for the institution of fairly vigorous physiotherapy as soon as pain and tenderness have disappeared. After an isolation period of three weeks, arrangements should be made to secure continued orthopaedic supervision and treatment, preferably by transfer of the patient to an orthopaedic hospital. It is important to see that those patients who have been regarded as " non-paralytic " are brought back for review three to six months later. Minor degrees of paralysis—especially of spinal muscles—may easily be overlooked during the acute stage.
The early period of the major illness is often regarded as a time when there is " nothing to be done ". This is not the case. As soon as tenderness is gone, movement should be begun—passive if the muscle group is powerless but with assistance against gravity where minimal contraction is present. Movement under water requires less muscle power and can be started early. The patient may be trained in simple muscle contractions which will enhance the chance of recovery. In other words, activity should be encouraged as soon as freedom from discomfort permits.
The virus enters the body by the mouth, multiplies in the cells of the intestinal mucosa, and is excreted in the faeces. The central nervous system is reached by way of the blood stream so that virasmia precedes the onset of clinical evidence of involvement of nerve cells. The infectivity varies greatly, but it would appear that the fsecal excretion of virus is greatest in the most severe cases. Virus is present in the stool of all paralytic cases, the excretion slowly waning over a period of eight to ten weeks. In about half the patients, stool cultures become negative in three to four weeks.Poliomyelitis is a notifiable disease. There are three serological types of poliomyelitis virus, of which Types i and 2 seem to be the more frequent epidemic producers. The incubation period probably varies widely although in most cases it lies between seven and ten days Prevention and Epidemiological Control.—Specific Prophylaxis.—The known presence of antibody in the serum of many adults encouraged the use of gamma-globulin to confer a temporary passive immunity and thus to prevent the disease in contacts along lines exactly similar to those which proved successful in measles. Although theoretically sound, it is not a practicable method of control and its use is not advocated.
Two varieties of polio vaccine are available:
(1) The first (Salk-type) consists of formalin-killed viruses of the three antigenic types. This material is injected intramuscularly or sub-cutaneously in doses of i -o ml. The first two injections are given with an interval of four weeks ; a third dose after a period of six months is an essential part of the immunization programme and, indeed, it is desirable to give a fourth injection a year or two later. The vaccines which are now available have undergone careful safety tests ; they contain an increased quantity of antigen, and are very effective in inducing a measurable humoral immunity. The widespread use of Salk-type vaccine has been responsible for a sharp decline in the incidence of poliomyelitis in the United States and Britain.
(2) The second (Sabin-type) vaccine consists of live attenuated polioviruses. It may be obtained in monotypic form (most commonly used in North America) or in tri-typic form (mainly used in this country). This vaccine is easily administered : the dose is dropped on a lump of sugar or similar vehicle which is then taken by mouth. The live virus infects the cells of the gastro-intestinal tract so that it is excreted in the stool for a considerable time after administration. Subsequently antibodies can be demonstrated in the serum.Appraisal of the Two Vaccines.—Both vaccines, in their present form, offer satisfactory immunity. With the killed virus vaccine this immunity is purely a humoral one so that, although poliovirus is prevented from reaching the central nervous system, intestinal infection can still occur. This can constitute a disadvantage to the older contacts of vaccinated children since unsuspected infection of the vaccinated might enhance the exposure of the unvaccinated. Further, with the passage of time, immunity might be expected to wane in the older person, who would, however, be less inclined to present himself for " booster " injections. Finally, there is the slight inconvenience involved in its intramuscular injection.
The live attenuated virus vaccine is free from most of these disadvantages. The simplicity of its administration has meant that large townships have been immunized in a carefully organized, one-day programme. In the face of a rising incidence of the disease this could permit the application of the vaccine very rapidly—preferably using a monotypic vaccine of a type not causing the epidemic —and indeed this method would seem to have been successful in halting the progress of an epidemic. It may be that in such conditions an " interference phenomenon " comes into plav; the bowel cells become infected with the " tamed " strain and prevent the " wild " virus from successfully colonizing them.
The fear of " antigenic shift "—the mutation of low virulence to higher virulence strains during intestinal passage—would not, in the event, seem to have been of practical significance. There is some evidence that minor antigenic change occurs but, having regard to the very large populations that have been successfully vaccinated, there has been no indication of harmful effect. Some cases of paralysis have occurred in vaccinated subjects, usually in adults, which could possibly be attributed to the administered virus. Such events, however, have been of the order of one in several millions vaccinated and absolute proof that the vaccine virus was responsible has often been lacking.
There probably exists a place for both vaccines. If the '' quadruple vaccine " (diphtheria, tetanus, pertussis and killed poliovirus combined) could be produced free from side-effects, there would be much to be said in its favour. It would, however, be unlikely to contribute to the eradication of the disease. There is ground for believing that a really intensive world-wide campaign, using the live attenuated vaccine, would be likely to interfere seriously with the natural history of the virulent poliovirus. The vaccine of choice, therefore, is that of the live attenuated form—preferably administered on a widespread scale during the non-polio season of the year.
General Measures.—By the time that a diagnosis of paralytic poliomyelitis is made it may be assumed that infection has been well distributed among the immediate contacts. This makes effective control very difficult. There is, however, agreement that the patient must be promptly and effectively isolated and this is best done by admission to an infectious diseases hospital. Children who have been in contact with the patient should be kept under strict medical surveillance for a period of three weeks from the date of last contact. Adult contacts may continue their occupation providing it does not entail mixing with children, as in the case of nurses and school-teachers. They should, however, abstain from all social activities for three weeks from the date of last contact; kissing or playing with. young children must be strictly forbidden.
Any form of strenuous activity should be avoided. A contact who suffers from a febrile illness or who complains of any symptoms suggestive of an abortive attack of poliomyelitis should be strictly isolated until recovery ensues. Bed rest should be insisted on for a period of at least one week. During epidemics the practitioner should advise mothers to ensure that children are not over-active and that they secure adequate rest. A short period of enforced rest immediately after the midday meal is a sensible measure.
It is now accepted that certain factors provoke and determine the nature of the predominant paralysis. For example, tonsillectomy may be followed by a severe form of bulbar infection. During periods of prevalence operations on the nose and throat should not be undertaken. Intramuscular injections may be followed by considerable local reaction and this has been associated with paralysis in the limb used for the injection. Alum-containing vaccines have been especially incriminated and for this reason immunization programmes are often temporarily suspended during periods of increased prevalence. This risk should be eliminated by ensuring that polio vaccination is carried out early in life and immunity maintained by " booster " doses. Pregnancy renders women more vulnerable to infection by poliomyelitis, and therefore in the care of the expectant mother immunization with killed vaccine is desirable. Finally excessive muscular activity during the period when the person is infected with the virus may contribute to the development of severe paralysis. Hence, during periods of increased poliomyelitis prevalence additional caution is justified in the treatment of any unexplained febrile illnesses, for these may be in fact minor reactions to polio virus infection. After recovery from such illnesses energetic sports should be forbidden for a week or two.
Curative Treatment.—Serum Treatment.—Neither convalescent serum nor gamma-globulin has effect upon the course of poliomyelitis, for by the time a diagnosis has been made the virus is in the nerve cells and beyond the reach of antibody.
General Management.—The " Minor " Illness.—It is easy to seem over-fearful of poliomyelitis, but there is no doubt that few infections rouse such strong emotional reactions in parents. Since the symptoms of the minor illness are vague and non-specific—fever, headache, vomiting or nausea, pain in the back, stiffness of the neck, drowsiness or irritability with, in the more severe forms, muscular pains or weakness—the condition will only be recognized when there is either a history of contact with a case of paralytic illness or when the disease is known to be present in the district. In such circumstances it is wise to adopt caution in dealing with minor febrile illnesses and to counsel complete rest. It seems possible that strict bed rest in such cases may minimize, though it will not always completely prevent, subsequent paralysis.
The " Major " Illness.—This may be suspected when there is extreme irritability, muscle tenderness or pain or obvious paralysis. Spinal and neck stiffness is usual in these cases : hence the patient either cannot sit up, or when he does so cannot bend forward to make the chin touch the knees. Unnecessarily " finicky " examinations should be avoided ; careful observation will permit accurate diagnosis and the full assessment of paralysis can await the disappearance of muscle pain and tenderness. This pain and tenderness can be most commanding and may be relieved by continuous hot flannel packs. The affected limbs should be placed in a position of rest by means of properly placed pillows and sandbags and by the use of a " cage " to take the weight of bedclothes. When the patient is being treated outside of hospital, the advice of an ortho-pasdic surgeon should be immediately obtained.
When the shoulder-girdle muscles are involved, the possibility of interference with respiratory efficiency must always be kept in mind. Careful examination to exclude diaphragmatic paralysis must be made. The patient should be asked to count from one upwards to see how far he can get with a single breath. The test can be frequently repeated and forms a useful gauge of diminishing respiratory control. It is important to differentiate between respiratory insufficiency due to lack of muscle power in diaphragm and inter-costals from that due to obstruction of the airways by mucoid secretions from loss of the power of swallowing. These latter cases—the true " bulbar " forms— often present as respiratory infections or pneumonia, and their early recognition is of great importance. Here the immediate need is the establishment of adequate drainage, which is best obtained in the prone position with the foot of the bed raised. Suction of the pharyngeal secretions must be frequently carried out and every care taken to ensure a clear airway. Contrary to the common belief, these purely bulbar cases, when properly managed, will usually recover; the patient who is in greatest danger is the one in whom there is a combination of spinal and bulbar involvement, when the most skilled medical and nursing care is essential. All preparations must be made to maintain respiration (p. 688).
When all muscle tenderness has disappeared, simple splints (e.g. Cramer wire) should be applied under the guidance of an orthopsedic surgeon, who should, in fact, be called upon to assist in the supervision of the patient from the onset of paralysis. The limb should never be encased in plaster but should lie in plaster " shells " or padded Cramer wire splints made to the individual's requirements so that daily gentle massage and passive movements of the affected limbs may be supplemented by the local application of hot packs. There is a good deal to be said for the institution of fairly vigorous physiotherapy as soon as pain and tenderness have disappeared. After an isolation period of three weeks, arrangements should be made to secure continued orthopaedic supervision and treatment, preferably by transfer of the patient to an orthopaedic hospital. It is important to see that those patients who have been regarded as " non-paralytic " are brought back for review three to six months later. Minor degrees of paralysis—especially of spinal muscles—may easily be overlooked during the acute stage.
The early period of the major illness is often regarded as a time when there is " nothing to be done ". This is not the case. As soon as tenderness is gone, movement should be begun—passive if the muscle group is powerless but with assistance against gravity where minimal contraction is present. Movement under water requires less muscle power and can be started early. The patient may be trained in simple muscle contractions which will enhance the chance of recovery. In other words, activity should be encouraged as soon as freedom from discomfort permits.
MUMPS (Epidemic Parotitis)
The infective agent in mumps is a virus which is present in the saliva during the acute stage of the illness. Infectivity probably persists from the onset of the first symptom until the swelling of the salivary glands has subsided. Although the parotid is the gland most frequently involved, it is well to remember that the submaxillary or sublingual salivary glands may be exclusively affected and that abortive attacks of mumps, owing to the lack of facial deformity, may readily be missed. Indeed, some cases present with meningitis, and parotid involvement either does not occur or develops as a secondary manifestation. The occurrence of a lymphocytosis in the blood is of some diagnostic value.
Mumps is not a notifiable disease. The incubation period varies from 12 to 26 days, but'usually lies between 17 and 21 days.
Preventive Treatment.—Specific Prophylaxis.—Although the prevention of mumps by the use of gamma-globulin prepared from the blood of convalescent patients—as in measles—is possible, it should rarely be practised. Indeed, it should be stated emphatically that no attempt should ever be made to avoid mumps occurring in a child under 12 years. Orchitis, which is the most serious complication, only occurs in the adult and indeed the whole course of the infection is more severe once puberty is passed.General Measures.—Strict isolation of the patient is unnecessary. By the time a diagnosis is made susceptible contacts will have become infected. This usually results in a crop of secondary cases, but many people acquire immunity without developing clinical manifestations of the disease. The incubation period is so long that, when the date of exposure is definitely known, an exposed person should continue with his normal activities for the first fourteen days. The contact should be seen daily thereafter and put to bed on the first suspicion of illness. Exposure to infection should be avoided by women in the early months of pregnancy.
Curative Treatment.—General Management.—There is no specific treatment for mumps, and the administration of antibiotics is entirely unjustified.
The patient should be confined to bed until the swelling subsides. Rest in bed does not prevent the occurrence of orchitis, and mild cases even in adults may be allowed up by the fifth or sixth day. Difficulty in opening the mouth and pain on mastication are indications for the restriction of the diet to fluids and soft solids.
Hot dry cotton-wool or hot fomentations applied to the swollen glands will help to relieve pain and local discomfort. The mouth should be washed out with a i : 5,000 solution of permanganate of potash or other mild antiseptic preparation four times daily.
Treatment of Complications.—Orchitis usually develops when the parotid swelling is at its height and may be expected in approximately 20 per cent. of males above the age of puberty. The patient may have a very high fever, may look toxic and ill and be extremely depressed. He will need constant reassurance that recovery is the rule. The scrotum should be surrounded with cotton-wool and the inflamed parts supported either by a pillow placed between the thighs or by a suspensory bandage. The administration of corticosteroids for three to four days greatly reduces the testicular swelling. An initial dose of 40 mg. prednisolone per day should be gradually reduced as the oedema subsides.
Abdominal pain and vomiting are usually due to pancreatitis. A hot bag or hot fomentations applied to the site of the pain, with limitation of food and the exclusion of fat from the diet, will give relief. If the pain is severe, o-i g. of pethidine may be injected hypodermically.
Meningeal symptoms are not uncommon in some epidemics, "and, if severe, can be relieved by repeated lumbar puncture. There is no effective treatment for acute labyrinthitis, which is fortunately very rare.
Convalescence.—In children, convalescence is rapid. In the adult encephalitis is probably commoner than it is recognized and this may account for the severe mental depression which is often a feature of the illness even when orchitis has not occurred. In such cases the return to normal activity should not be hurried.
Mumps is not a notifiable disease. The incubation period varies from 12 to 26 days, but'usually lies between 17 and 21 days.
Preventive Treatment.—Specific Prophylaxis.—Although the prevention of mumps by the use of gamma-globulin prepared from the blood of convalescent patients—as in measles—is possible, it should rarely be practised. Indeed, it should be stated emphatically that no attempt should ever be made to avoid mumps occurring in a child under 12 years. Orchitis, which is the most serious complication, only occurs in the adult and indeed the whole course of the infection is more severe once puberty is passed.General Measures.—Strict isolation of the patient is unnecessary. By the time a diagnosis is made susceptible contacts will have become infected. This usually results in a crop of secondary cases, but many people acquire immunity without developing clinical manifestations of the disease. The incubation period is so long that, when the date of exposure is definitely known, an exposed person should continue with his normal activities for the first fourteen days. The contact should be seen daily thereafter and put to bed on the first suspicion of illness. Exposure to infection should be avoided by women in the early months of pregnancy.
Curative Treatment.—General Management.—There is no specific treatment for mumps, and the administration of antibiotics is entirely unjustified.
The patient should be confined to bed until the swelling subsides. Rest in bed does not prevent the occurrence of orchitis, and mild cases even in adults may be allowed up by the fifth or sixth day. Difficulty in opening the mouth and pain on mastication are indications for the restriction of the diet to fluids and soft solids.
Hot dry cotton-wool or hot fomentations applied to the swollen glands will help to relieve pain and local discomfort. The mouth should be washed out with a i : 5,000 solution of permanganate of potash or other mild antiseptic preparation four times daily.
Treatment of Complications.—Orchitis usually develops when the parotid swelling is at its height and may be expected in approximately 20 per cent. of males above the age of puberty. The patient may have a very high fever, may look toxic and ill and be extremely depressed. He will need constant reassurance that recovery is the rule. The scrotum should be surrounded with cotton-wool and the inflamed parts supported either by a pillow placed between the thighs or by a suspensory bandage. The administration of corticosteroids for three to four days greatly reduces the testicular swelling. An initial dose of 40 mg. prednisolone per day should be gradually reduced as the oedema subsides.
Abdominal pain and vomiting are usually due to pancreatitis. A hot bag or hot fomentations applied to the site of the pain, with limitation of food and the exclusion of fat from the diet, will give relief. If the pain is severe, o-i g. of pethidine may be injected hypodermically.
Meningeal symptoms are not uncommon in some epidemics, "and, if severe, can be relieved by repeated lumbar puncture. There is no effective treatment for acute labyrinthitis, which is fortunately very rare.
Convalescence.—In children, convalescence is rapid. In the adult encephalitis is probably commoner than it is recognized and this may account for the severe mental depression which is often a feature of the illness even when orchitis has not occurred. In such cases the return to normal activity should not be hurried.
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