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SEASONAL VARIATION OF INFECTIOUS DISEASES.
302
SEASONAL VARIATION OF INFECTIOUS DISEASES.
the evidence is not very definite. The method o:)f variations are therefore of particular interest. preparation used by COLLIP is briefly as follows :- Dr. MADSEN showed how the Danish morbidity The minced placenta is extracted with alcohol1, statistics confirm in all details those noted by the the active principle being soluble in all strengths o:)f older observers and conform closely with the this solvent. After removal of the alcohol b periodicities of other European countries distillation and of the lipoids by extraction witl and North America. Scarlatina, diphtheria, angina ether, the solution is suitable for clinical use. Crystalsls can be obtained by addition of ammonia to th( Le tonsillaris, and acute rheumatism, for instance, ute;! concentrated solution. The purified product &Iacincrease during the autumn to a maximum in relatively insoluble in water and about 1 mg. i, drop a little in December, rise to a The potency Í! obtained from a kilo of placenta. in January, and then fall to a minimum unaffected by boiling for five minutes in dilute acetic second peak acid, though the saline solution may deteriorate orn in July. Broncho-pneumonia, bronchitis, and influkeeping. No further chemical details are given of thEe enza display a decided maximum in January and properties of the hormone since the amount availablee February, falling to a minimum in August. The as yet for experimental work has been insufficient. The unit of the purified substance is provisionally incidence of croupous pneumonia follows the considered to be of the order of 0’0015 mg. same curves, but does not reach its maximum until In this process the preliminary treatment withb. March-April. Another winter-spring group is alcohol would facilitate the extraction of thee formed by cerebro-spinal meningitis and oestrin from the placenta. After removal of thee encephalitis ; the former has its maximum in fats with ether, probably only a trace of oestrinn February and the latter in April-May. Among would remain in the aqueous portion. Thee the summer-autumn infections are epidemic diarquestion arises as to whether this amount iss rhoea, typhoid fever, and poliomyelitis. The last of responsible for any of the physiological actionss these runs a curiously opposite seasonal course to . observed by CoLLrP-i.e., the production off the other nervous epidemics, so that Dr. MADSEN precocious maturity in the experimental animals.!. wonders whether the intestinal canal may not play a part in its eatiology. Measles and whoopingCoLMT’s concluding words on this point are : " It has been suggested .... that oestrin orr cough show no regular seasonal fluctuations, but ’theelin,’ as Doisy has now named the ovarian1 it is a peculiar feature of any measles epidemic hormone, has not been entirely removed from ourr that there is always a depression in the month of extract, and that the oestrus effects which have been obtained by its use may be attributable to traces of September. In the southern hemisphere the curves this hormone. Due to the consistent negativee are reversed to correspond with reversed seasons. results which extracts of human placenta have given1 Dr. MADSEN considers and rejects the theory when tested on oophorectomised animals, it wasS that the variations may be on the bacterial side, felt that this interfering factor had been adequately himself with SYDENEAM in looking and allies controlled. Larger doses will have to be given in the oestrin assay, over longer periods of time, to makee for some periodic change in man. N. FINSEN and this point clearer." L. ISACHSEN have found a periodic fluctuation in The wisdom of repeating and extending the3 the quantity of haemoglobin and the number of experiments to cover these important points, and1 blood corpuscles, with a minimum in January and to indicate in a more definite way the true nature3 a maximum in July. J. LINDHARD has found a of the active substance or substances is obvious. similar oscillation in the frequency and depth of The new name " emmenin " proposed for therespiration, the quotient of ventilation, and the active substance, in CoLUPs most recent paper, alveolar carbonic acid tension ; this he ascribes seems appropriate, but its general adoption is3not to temperature but to light. Dr. MADSEN until final been to be has therefore beside his the sunshine other curves likely delayed proof puts obtained of its identity. This important work has3 returns for the year, and plots in one figure the aroused so much interest in clinical as well as bio- general mortality-rate, the incidence of bronchitis, chemical circles that the results of its further and the respiratory frequency ; the curves follow one another with remarkable faithfulness. Annual development will be eagerly looked for. fluctuations are also known to occur in bodily weight-a minimum in February and a maximum SEASONAL VARIATION OF INFECTIOUS in September-and in the vitamin content of food. DISEASES. Dr. MADSEN treads cautiously among these THE parasitic nature of epidemic disease having fascinating possibilities, and points out the enorbeen established beyond all reasonable doubt, there mous field that yet remains unharvested. He has been a recrudescence of interest in the equally ventures to suggest, however, as a prophylactic well established seasonal variation in endemic and measure, an effort to secure more efficient light in epidemic infection, which occupied so much of the the dark period, and urges the medical profession attention of the older school of epidemiologists. to encourage people to get out into the open air Dr. T. J. MADSEN, in an addressdelivered at the and sunlight as much as possible in winter. The French Academy of Medicine lately London School of Hygiene, surveys the seasonal factor in Danish epidemics during the last 40 years. listened to a discourse on a similar subject2 by In Denmark notification of all infectious diseases Dr. M. A. TRILLAT, who has been impressed by the has long been obligatory ; the land has long been importance of barometric pressure on the origin and sheltered from natural catastrophes and war ; there duration of epidemics. In support of this thesis has been no great epidemic, and climatic differences he quotes the mortality of the European influenza in this small country are not marked. Seasonal epidemic of 1889 to 1890, in which, he says, the -
h seasonal
November, c y
fSept mb r. 3
.
,
.
.
,
1 Public Health, July, 1930, p. 309.
2
Bull. de l’Acad. de Méd., 1930, ciii., 698.
303
INTRABRONCHIAL DRAINAGE.
associated with bronchiectasis is, at times,. limited to a single lobe, while except in the earliest stages of the disease unilateral tuberculosis is very infrequent. The manner in which the disease spreads to the contra-lateral organ makes it almost certain that this spread is due to inhalation from the affected side. In a recent paper on intrabronchial drainage HAROLD BRUNN and WILLIAM B. FAULKENER1 remark that proper evaluation has not been given to the mechanical factors which are present in nearly every case of pulmonary suppuration. They point out that drainage of a suppurating In the area in a lung may be external or internal. matter is removed former, septic by expectoration. In the latter, pus welling up from the diseased focus spills over into adjacent bronchi, or crosses the tracheal carina, to track into the opposite lung. Failure to appreciate the mobility of septic matter within the lung tubes may lead to error in diagnosis of the site of disease. Thus an upper lobe abscess may discharge its contents into the lower bronchi, and in such a case, after the patient has maintained the erect position for some hours, the physical signs may suggest a lower, rather than an upper, a for as one sees lobe lesion. On the other hand, if secretion is not factor " ; example, high humidity, in a common mist or fog, permits the maintenance excessive external drainage may suffice.to maintain and suspension of microbe-containing droplets for the dilated tubes of an upper lobe bronchiectasis in a longer period than in a dry atmosphere. a fairly dry condition.22 Mechanical factors, again, Undoubtedly both factors are important deter- may determine the flow of pus from the left lower minants of seasonal morbidity, but which is the to the right upper lobe if the patient remains more important is unknown. Their weight probably recumbent on his right side. The violent spasms varies greatly in different types of disease and of coughing to which the victims of pulmonary environment. Finally it is interesting to note how suppuration are liable is due to bronchial blockage. all epidemiologists have given up " bacterial BRUNN and FAULRENER point out that the variation " as an important cause of the seasonal injection of lipiodol by the oral route causes no changes in morbidity,just put forward by cough unless a bronchus becomes obstructed PASTEUR. We wonder if they are always justified through the accumulation of oil, when violent in doing so. coughing is at once aroused. Sudden occlusion of 0 a bronchus will cause severe cough even though all INTRABRONCHIAL DRAINAGE. possibility of bronchial irritation has been abolished described as the been most has perfectly by cocaine. This, observation has an important THE lung drained organ in the body. Free outlets, however, bearing on the posture of a patient during certain mean free inlets, and the bronchial system which operations on the chest. If, for example, during for the of such a the patient lies upon abscess for easy passage gives expectoration pneumotomy secretions and debris facilitates the rapid spread of his sound side, pus from the diseased lung may infection from the primary airways to the lung spill into the opposite main bronchus, and the tubes, from one side of the chest to the other, and patient will be in danger of’ choking, unless the from terminal bronchi to air cells. In the chest, as violent, and otherwise very undesirable, spasm of elsewhere, we must learn to think of diseases as coughing set up leads to expectoration. Such a. affecting not organs but systems. The pulmonary misadventure is obviated by bronchoscopy before tract is one and indivisible. We might almost operation,y and the bronchoscopic cleansing of say that though there are five lobes there is only after operation is an additional safeguard. one lung. The ease with which fluids pass from Internal drainage is not limited to lipiodol the upper air passages to the main bronchi and injections or pulmonary suppurations. It is their subdivisions is demonstrated by the injection significant that in a migrating " pneumonia the of lipiodol. Under the fluoroscopic screen the physical signs of consolidation over one upper oil can be seen to reach the terminal bronchioles lobe are often followed by the development of within two or three minutes of its injection. A similar signs at the opposite lung base. Such an very slight tilting of the patient suffices to determine event is, perhaps, rightly interpreted as due to a the flow to the right or left lung. Oilinjectedinto spill over of infection and a flow determined by a bronchial fistula of one lung can be made to flow mechanical considerations. into the opposite lung by a simple change of posture. Harold Brunn, M.D., and William B. Faulkener, jun., M.D. : It is not surprising that chronic pulmonary Intrabronchial Drainage, Amer. Jour. Surg., Gyn., and Obst., July, 1930, p. 115. affections are usually bilateral, and we may 2 W. Burton Wood: The Oral Injection of Lipiodol as an Aid the Differential Diagnosis of Upper Lobe Bronchiectasis and well wonder how it can be that infection to Pulmonary Tuberculosis, THE LANCET, 1930, i., 1339. He! rose and fell with the humidity. been noted that a has similar states correspondence in other epidemics, though not in the influenza epidemic of 1918. Here he supports Sir LEONARD ROGERS, whose numerous brilliant investigations have shown how closely the incidence of many infectious diseases in correlated with the " absolute humidity " of the atmosphere. Dr. TRILLAT himself attributes the action of humidity on disease incidence to its effect on the transmission of " droplet infection." Thus far most modern epidemiologists would be inclined to agree with him, but when he speculates that sudden barometric depressions cause an evolution of gases from soil and organic refuse, and that these gases form a suitable nutritive medium for organisms growing or multiplying in the air, he has probably lost the sympathy of the modern bacteriologist who no longer believes that specific pathogens can multiply to any extent in the atmosphere. These two papers form an interesting contrast; the one attributes the action of season and climate to its effects on the host, producing alterations in resistance to infection. The other attributes the effects of season to alterations in the " transmission
mortality
I
"
1
SEASONAL VARIATION OF INFECTIOUS DISEASES.
the evidence is not very definite. The method o:)f variations are therefore of particular interest. preparation used by COLLIP is briefly as follows :- Dr. MADSEN showed how the Danish morbidity The minced placenta is extracted with alcohol1, statistics confirm in all details those noted by the the active principle being soluble in all strengths o:)f older observers and conform closely with the this solvent. After removal of the alcohol b periodicities of other European countries distillation and of the lipoids by extraction witl and North America. Scarlatina, diphtheria, angina ether, the solution is suitable for clinical use. Crystalsls can be obtained by addition of ammonia to th( Le tonsillaris, and acute rheumatism, for instance, ute;! concentrated solution. The purified product &Iacincrease during the autumn to a maximum in relatively insoluble in water and about 1 mg. i, drop a little in December, rise to a The potency Í! obtained from a kilo of placenta. in January, and then fall to a minimum unaffected by boiling for five minutes in dilute acetic second peak acid, though the saline solution may deteriorate orn in July. Broncho-pneumonia, bronchitis, and influkeeping. No further chemical details are given of thEe enza display a decided maximum in January and properties of the hormone since the amount availablee February, falling to a minimum in August. The as yet for experimental work has been insufficient. The unit of the purified substance is provisionally incidence of croupous pneumonia follows the considered to be of the order of 0’0015 mg. same curves, but does not reach its maximum until In this process the preliminary treatment withb. March-April. Another winter-spring group is alcohol would facilitate the extraction of thee formed by cerebro-spinal meningitis and oestrin from the placenta. After removal of thee encephalitis ; the former has its maximum in fats with ether, probably only a trace of oestrinn February and the latter in April-May. Among would remain in the aqueous portion. Thee the summer-autumn infections are epidemic diarquestion arises as to whether this amount iss rhoea, typhoid fever, and poliomyelitis. The last of responsible for any of the physiological actionss these runs a curiously opposite seasonal course to . observed by CoLLrP-i.e., the production off the other nervous epidemics, so that Dr. MADSEN precocious maturity in the experimental animals.!. wonders whether the intestinal canal may not play a part in its eatiology. Measles and whoopingCoLMT’s concluding words on this point are : " It has been suggested .... that oestrin orr cough show no regular seasonal fluctuations, but ’theelin,’ as Doisy has now named the ovarian1 it is a peculiar feature of any measles epidemic hormone, has not been entirely removed from ourr that there is always a depression in the month of extract, and that the oestrus effects which have been obtained by its use may be attributable to traces of September. In the southern hemisphere the curves this hormone. Due to the consistent negativee are reversed to correspond with reversed seasons. results which extracts of human placenta have given1 Dr. MADSEN considers and rejects the theory when tested on oophorectomised animals, it wasS that the variations may be on the bacterial side, felt that this interfering factor had been adequately himself with SYDENEAM in looking and allies controlled. Larger doses will have to be given in the oestrin assay, over longer periods of time, to makee for some periodic change in man. N. FINSEN and this point clearer." L. ISACHSEN have found a periodic fluctuation in The wisdom of repeating and extending the3 the quantity of haemoglobin and the number of experiments to cover these important points, and1 blood corpuscles, with a minimum in January and to indicate in a more definite way the true nature3 a maximum in July. J. LINDHARD has found a of the active substance or substances is obvious. similar oscillation in the frequency and depth of The new name " emmenin " proposed for therespiration, the quotient of ventilation, and the active substance, in CoLUPs most recent paper, alveolar carbonic acid tension ; this he ascribes seems appropriate, but its general adoption is3not to temperature but to light. Dr. MADSEN until final been to be has therefore beside his the sunshine other curves likely delayed proof puts obtained of its identity. This important work has3 returns for the year, and plots in one figure the aroused so much interest in clinical as well as bio- general mortality-rate, the incidence of bronchitis, chemical circles that the results of its further and the respiratory frequency ; the curves follow one another with remarkable faithfulness. Annual development will be eagerly looked for. fluctuations are also known to occur in bodily weight-a minimum in February and a maximum SEASONAL VARIATION OF INFECTIOUS in September-and in the vitamin content of food. DISEASES. Dr. MADSEN treads cautiously among these THE parasitic nature of epidemic disease having fascinating possibilities, and points out the enorbeen established beyond all reasonable doubt, there mous field that yet remains unharvested. He has been a recrudescence of interest in the equally ventures to suggest, however, as a prophylactic well established seasonal variation in endemic and measure, an effort to secure more efficient light in epidemic infection, which occupied so much of the the dark period, and urges the medical profession attention of the older school of epidemiologists. to encourage people to get out into the open air Dr. T. J. MADSEN, in an addressdelivered at the and sunlight as much as possible in winter. The French Academy of Medicine lately London School of Hygiene, surveys the seasonal factor in Danish epidemics during the last 40 years. listened to a discourse on a similar subject2 by In Denmark notification of all infectious diseases Dr. M. A. TRILLAT, who has been impressed by the has long been obligatory ; the land has long been importance of barometric pressure on the origin and sheltered from natural catastrophes and war ; there duration of epidemics. In support of this thesis has been no great epidemic, and climatic differences he quotes the mortality of the European influenza in this small country are not marked. Seasonal epidemic of 1889 to 1890, in which, he says, the -
h seasonal
November, c y
fSept mb r. 3
.
,
.
.
,
1 Public Health, July, 1930, p. 309.
2
Bull. de l’Acad. de Méd., 1930, ciii., 698.
303
INTRABRONCHIAL DRAINAGE.
associated with bronchiectasis is, at times,. limited to a single lobe, while except in the earliest stages of the disease unilateral tuberculosis is very infrequent. The manner in which the disease spreads to the contra-lateral organ makes it almost certain that this spread is due to inhalation from the affected side. In a recent paper on intrabronchial drainage HAROLD BRUNN and WILLIAM B. FAULKENER1 remark that proper evaluation has not been given to the mechanical factors which are present in nearly every case of pulmonary suppuration. They point out that drainage of a suppurating In the area in a lung may be external or internal. matter is removed former, septic by expectoration. In the latter, pus welling up from the diseased focus spills over into adjacent bronchi, or crosses the tracheal carina, to track into the opposite lung. Failure to appreciate the mobility of septic matter within the lung tubes may lead to error in diagnosis of the site of disease. Thus an upper lobe abscess may discharge its contents into the lower bronchi, and in such a case, after the patient has maintained the erect position for some hours, the physical signs may suggest a lower, rather than an upper, a for as one sees lobe lesion. On the other hand, if secretion is not factor " ; example, high humidity, in a common mist or fog, permits the maintenance excessive external drainage may suffice.to maintain and suspension of microbe-containing droplets for the dilated tubes of an upper lobe bronchiectasis in a longer period than in a dry atmosphere. a fairly dry condition.22 Mechanical factors, again, Undoubtedly both factors are important deter- may determine the flow of pus from the left lower minants of seasonal morbidity, but which is the to the right upper lobe if the patient remains more important is unknown. Their weight probably recumbent on his right side. The violent spasms varies greatly in different types of disease and of coughing to which the victims of pulmonary environment. Finally it is interesting to note how suppuration are liable is due to bronchial blockage. all epidemiologists have given up " bacterial BRUNN and FAULRENER point out that the variation " as an important cause of the seasonal injection of lipiodol by the oral route causes no changes in morbidity,just put forward by cough unless a bronchus becomes obstructed PASTEUR. We wonder if they are always justified through the accumulation of oil, when violent in doing so. coughing is at once aroused. Sudden occlusion of 0 a bronchus will cause severe cough even though all INTRABRONCHIAL DRAINAGE. possibility of bronchial irritation has been abolished described as the been most has perfectly by cocaine. This, observation has an important THE lung drained organ in the body. Free outlets, however, bearing on the posture of a patient during certain mean free inlets, and the bronchial system which operations on the chest. If, for example, during for the of such a the patient lies upon abscess for easy passage gives expectoration pneumotomy secretions and debris facilitates the rapid spread of his sound side, pus from the diseased lung may infection from the primary airways to the lung spill into the opposite main bronchus, and the tubes, from one side of the chest to the other, and patient will be in danger of’ choking, unless the from terminal bronchi to air cells. In the chest, as violent, and otherwise very undesirable, spasm of elsewhere, we must learn to think of diseases as coughing set up leads to expectoration. Such a. affecting not organs but systems. The pulmonary misadventure is obviated by bronchoscopy before tract is one and indivisible. We might almost operation,y and the bronchoscopic cleansing of say that though there are five lobes there is only after operation is an additional safeguard. one lung. The ease with which fluids pass from Internal drainage is not limited to lipiodol the upper air passages to the main bronchi and injections or pulmonary suppurations. It is their subdivisions is demonstrated by the injection significant that in a migrating " pneumonia the of lipiodol. Under the fluoroscopic screen the physical signs of consolidation over one upper oil can be seen to reach the terminal bronchioles lobe are often followed by the development of within two or three minutes of its injection. A similar signs at the opposite lung base. Such an very slight tilting of the patient suffices to determine event is, perhaps, rightly interpreted as due to a the flow to the right or left lung. Oilinjectedinto spill over of infection and a flow determined by a bronchial fistula of one lung can be made to flow mechanical considerations. into the opposite lung by a simple change of posture. Harold Brunn, M.D., and William B. Faulkener, jun., M.D. : It is not surprising that chronic pulmonary Intrabronchial Drainage, Amer. Jour. Surg., Gyn., and Obst., July, 1930, p. 115. affections are usually bilateral, and we may 2 W. Burton Wood: The Oral Injection of Lipiodol as an Aid the Differential Diagnosis of Upper Lobe Bronchiectasis and well wonder how it can be that infection to Pulmonary Tuberculosis, THE LANCET, 1930, i., 1339. He! rose and fell with the humidity. been noted that a has similar states correspondence in other epidemics, though not in the influenza epidemic of 1918. Here he supports Sir LEONARD ROGERS, whose numerous brilliant investigations have shown how closely the incidence of many infectious diseases in correlated with the " absolute humidity " of the atmosphere. Dr. TRILLAT himself attributes the action of humidity on disease incidence to its effect on the transmission of " droplet infection." Thus far most modern epidemiologists would be inclined to agree with him, but when he speculates that sudden barometric depressions cause an evolution of gases from soil and organic refuse, and that these gases form a suitable nutritive medium for organisms growing or multiplying in the air, he has probably lost the sympathy of the modern bacteriologist who no longer believes that specific pathogens can multiply to any extent in the atmosphere. These two papers form an interesting contrast; the one attributes the action of season and climate to its effects on the host, producing alterations in resistance to infection. The other attributes the effects of season to alterations in the " transmission
mortality
I
"
1