Tweet
most important thing in a pandemic seems to be a
mechanical dishwasher :
_________________
--------------------------------------------------------------------------------
Correction: the most important thing in institutions in 1918 was mechanical dishwashing.
Actually, interesting article. Obsolete, I would think, by today's measurements because there are Standards now for this sort of thing. Makes sense though: warm water vs. steam to kill bacteria.
It's something to bear in mind around our own houses in regards to infection control.
--------------------------------------------------------------------------------
remarcable the amount of infections transmitted by washing eating utensils !
Airborne,direct contact, contamination by hands etc. is not nearly as important.
What's the exact route of transmission ? Why wasn't it examined since 1918 ?
I assume it's mouth-spoon/fork-water-other spoon-mouth.
Or mouth-spoon-other mouth.
That would mean flu infects in the mouth !
It could be through the hands, touching the nose, but then we should see
more transmissions through other objects, not this dominance.
Drying the spoons and storing them for hours,days doesn't seem to reduce the viruses a lot.
================================================== =================
Mode of Transmission
The actual mechanics of the mode of transmission of the virus of influenza is a point over which argument has taken place. There is to-day substantial agreement that the disease is transmitted from individual to individual, rather than by aerial convection, although the latter hypothesis has found many proponents in the past. The known facts of the matter may all be explaoined without recourse to the theory of spread by air.
The generally accepted idea of the method of spread of this and similar diseases has been expressed in the general term applied to them, that of
"sputum-borne diseases." Most of the preventive work directed against influenza and the pneumonias has been based on this idea of the principal method of spread. The obvious fact that infective material is constantly sprayed into the air by the coughing patient, from which it is equally readily inhaled by those near by, has tended to render us oblivious of other possibilities perhaps as important. The rô of the hand in the spread of these diseases has been emphasized, particularly by Lunch and Cumming,25 and the importance of "hand-to-mouth" routes in disseminating infection has received much study. It can not be said that any agreement has been arrived at as to which method is of the greater importance in spreading disease. It is entirely probable that both methods play their part in the process.
That the number of new cases depends to a great extent on the closeness of contact between infected and noninfected individuals is shown in a number of ways. Though figures as to the crowding of camps during the epidemic are inconclusive, special studies made of the relation between floor space and influenza incidence in different units of the same camp, as shown above, indicate that there is a definite relation between crowding and the spread of the respiratory disease. The influence of varying degrees of closeness of contact is shown by figures reported from Camp Custer, Mich., during the fall epidemic (1918).26
Influence of contact on incidence and mortality, Camp Custer, September-October 1918
Percentage contracting influenza
Percentage contracting pneumonia
Deaths
Total camp,23.4,5.4,1.7
Medical and dental officers,25.6,5.5,1.2
Other officers,6.6,1.4,0.0
War men in base hospital,11.7,2.5,0.8
Other Medical Department men in hospital,12.5,2.6,1.5
Army nurses,30.6,10.4,1.4
Civilian nurses,36.4,6.6,0.8
This tabulation shows plainly the increased incidence in groups coming in closest contact with infected individuals.
Vaughan (Warren) showed a similar relation among civilians in Boston.27 His figures showed that "sleeping contact" was over twice as apt to result in infection as the less intimate forms of contact in the family. These figuress seem to have some significance in the question of the relative importance of the hand and droplet in transmission. Apparently the latter method is more concerned in sleepoing contact than the former. Lynch and Cumming25 maintained that the indirect transmission of infection from hand to hand by means of infected dishwater in the dipping method of washing mess kits was the major route of transmission. The figures presented in their report taken from organizations of the port of embarkation, Newport News, Va., support their contention satisfactorily. They have also shown by experimental methods that the route they suggest is a feasible one. Their conclusions have been criticized, however, on the ground that other factors known to be concerned in the incidence of the disease, such as length of service, crowding, etc., were not eliminated in making their comparisons. Other officers have failed to show a similar relation between their organizations.28 At Camp Jackson, S.C., a group of organizations, carefully using boiling water in the washing of mess kits but composed of men of short service, showed a very much higher incidence rate during the fall outbreak than did another organization of much longer service that took no special care to effect thorough sterilization of dishes. Both used the dipping method.29 Here aparently the element of length of service was far more important in determining mobidity than was the sterilization of the mess kits.
Special bacteriologic experiments conducted at Camp Meade, Md., showed that, even when relatively cool, the soap in the dishwater was sufficient to kill the usual organisms found in respiratory infections, such as the pneumococci
and streptococci.30 these experiments, however, did show the possibility of the transference of organisms of the colon group by this means. As far as the influeza virus is concerned, the results are entirely inconclusive, as the exciting agent of this disease is not yet definitely recognized.
The consensus of opinion, based on the experience of the epidemic, would seem to be that while the rôle of the hand in the direct and indirect transmission of respiratory disease should receive careful study and fullest consideration, the claim that this reprseents the major avenue of spread of theese diseases can hardly be regarded as proved, and attention to this possible means of travel of the virus should not be allowed to draw attention from methods of prevention based on the more usually accepted theories of the method of transmission.
in spite of all evidence pointing to the importance of contact, attempts to transmit the disease experimentally under controlled conditions have uniformly failed. The United States Public Health Service sponsored two experiments of this character during the fall outbreak in 1918.31 One experiment was carried on in Boston, with 100 volunteers from the Navy, of the most susceptible age. None were known to have had influenza previously. These men were treated with influenza bacilli, with nasopharyngeal secretions, with and without filtration, by intranasal sprays, and by direct swabbing from patient to volunteer. The attempt was made to induce the disease by the injection of citrated blood from patients and the injection of filtrates of nasophyaryngeal secretion. Finally these men were exposed to the most intimate personal contact with patients in wards, all with the complete failure to produce the disease. A similar experiment was conducted with the same result in San Francisco. The explanation of this result is lacking. either the proper method of transmitting the disease was not used, which seems very unlikely in view of the diversity of methods employed, or the volunteers themselves were immune to the disease either naturally or through previous infection in spite of their negative history. This latter hypothesis is hardly satisfactory though seemingly more probable than the former.
It can only be said then that the experience of the war has confirmed our pervious belief that influenza is carried by infected persons and not for any distance through the air. The exact means by which the virus is transmitted from person to person, as well as the usual portal of entry in each case, remains unknown. While other means of transmission can not be excluded, and doubtless play their part, the known facts are not inconsistent with the generally accepted idea that the secretions of the respiratory tract expelled into the air by the act of coughing and inhaled by susceptible person in the immediate neighborhood constitute the most important route.
As to the duration of the period of infectivity of the individual case, no reliable deductions may be made. The negative attempts at transmission experiments already quoted suggest the possibility that the infective period is very short, possibly even limited to the period of incubation or invasion. This idea is also supported by the observation that different methods adopted by different commands in the handling of their influenza cases apparently produced little effect on the incidence of the disease. Some camps attempted
the immediate hospitalization and isolation of all suspicious cases, others reserved their hospitals for the seirously ill only, leaving the lighter cases for treatment in regimental infirmaries or in quarters where opportunities for transmission to the uninfected would appear to be much more numerous. It is not possible to show that this latter method of handling the situation resulted in any increase in the relative number of cases. The possible explanation may lie in a very brief period of infectivity, limited to the period of invasion or the earliest hours of the demonstrable presence of the active disease.
25. Lynch, C. and Cumming, I.G.: The Rôle of the Hand in the distribtuion of Influenza Virus, and the Secondary Invaders. The Military Surgeon, 1918, xlii, 597; also, The Journal of Laboratory and Clinical Medicine, St. Louis, 1918, v, 364.
26. Blanton, W.R., and Irons, E.E.: A Recent epidemic of Acute Respiratory Infection at Camp Custer, Michigan. The Journal of the American Medical Association,1918, lxxi, No. 24, 1918.
27. Vaughan, W.T.: Monograph No. 1. The American Journal of Hygiene, 1921.
28. Jackson, Thomas W.: The Other Side of the Question of Indirect Contact Infection in Acute Respiratory Diseases. The Military surgeon, Washington, 1920, xlvi, No. 5, 570.
29. Hall, Milton W.: A Note on the Epidemiology of Influenza. The Military Surgeon,I Washington, 1920, xlvi, No. 5, 564.
30. Nichols, H.J.: Bacteriologic Data on the epidemiology of Respiratory Diseases in the Army. The Journal of Laboratory and Clinical Medicine, St. Louis, 1920, v. 502.
31. Rosenau, M.J.; Keegan, W.J.; Goldberger, J.; and Lake, G.C.: Some Interesting Though Unsuccessful Attempts 6to Transmit Influenza experimentally, Public Health Reports, 1919, xxxiv, No. 2, 33. Also, McCoy, G.W., and richey, De Wayne: San Francisco Experiments. Public Health Reports, 1919, xxxiv, No. 2, 34.
mechanical dishwasher :
_________________
--------------------------------------------------------------------------------
Correction: the most important thing in institutions in 1918 was mechanical dishwashing.
Actually, interesting article. Obsolete, I would think, by today's measurements because there are Standards now for this sort of thing. Makes sense though: warm water vs. steam to kill bacteria.
It's something to bear in mind around our own houses in regards to infection control.
--------------------------------------------------------------------------------
remarcable the amount of infections transmitted by washing eating utensils !
Airborne,direct contact, contamination by hands etc. is not nearly as important.
What's the exact route of transmission ? Why wasn't it examined since 1918 ?
I assume it's mouth-spoon/fork-water-other spoon-mouth.
Or mouth-spoon-other mouth.
That would mean flu infects in the mouth !
It could be through the hands, touching the nose, but then we should see
more transmissions through other objects, not this dominance.
Drying the spoons and storing them for hours,days doesn't seem to reduce the viruses a lot.
================================================== =================
Mode of Transmission
The actual mechanics of the mode of transmission of the virus of influenza is a point over which argument has taken place. There is to-day substantial agreement that the disease is transmitted from individual to individual, rather than by aerial convection, although the latter hypothesis has found many proponents in the past. The known facts of the matter may all be explaoined without recourse to the theory of spread by air.
The generally accepted idea of the method of spread of this and similar diseases has been expressed in the general term applied to them, that of
"sputum-borne diseases." Most of the preventive work directed against influenza and the pneumonias has been based on this idea of the principal method of spread. The obvious fact that infective material is constantly sprayed into the air by the coughing patient, from which it is equally readily inhaled by those near by, has tended to render us oblivious of other possibilities perhaps as important. The rô of the hand in the spread of these diseases has been emphasized, particularly by Lunch and Cumming,25 and the importance of "hand-to-mouth" routes in disseminating infection has received much study. It can not be said that any agreement has been arrived at as to which method is of the greater importance in spreading disease. It is entirely probable that both methods play their part in the process.
That the number of new cases depends to a great extent on the closeness of contact between infected and noninfected individuals is shown in a number of ways. Though figures as to the crowding of camps during the epidemic are inconclusive, special studies made of the relation between floor space and influenza incidence in different units of the same camp, as shown above, indicate that there is a definite relation between crowding and the spread of the respiratory disease. The influence of varying degrees of closeness of contact is shown by figures reported from Camp Custer, Mich., during the fall epidemic (1918).26
Influence of contact on incidence and mortality, Camp Custer, September-October 1918
Percentage contracting influenza
Percentage contracting pneumonia
Deaths
Total camp,23.4,5.4,1.7
Medical and dental officers,25.6,5.5,1.2
Other officers,6.6,1.4,0.0
War men in base hospital,11.7,2.5,0.8
Other Medical Department men in hospital,12.5,2.6,1.5
Army nurses,30.6,10.4,1.4
Civilian nurses,36.4,6.6,0.8
This tabulation shows plainly the increased incidence in groups coming in closest contact with infected individuals.
Vaughan (Warren) showed a similar relation among civilians in Boston.27 His figures showed that "sleeping contact" was over twice as apt to result in infection as the less intimate forms of contact in the family. These figuress seem to have some significance in the question of the relative importance of the hand and droplet in transmission. Apparently the latter method is more concerned in sleepoing contact than the former. Lynch and Cumming25 maintained that the indirect transmission of infection from hand to hand by means of infected dishwater in the dipping method of washing mess kits was the major route of transmission. The figures presented in their report taken from organizations of the port of embarkation, Newport News, Va., support their contention satisfactorily. They have also shown by experimental methods that the route they suggest is a feasible one. Their conclusions have been criticized, however, on the ground that other factors known to be concerned in the incidence of the disease, such as length of service, crowding, etc., were not eliminated in making their comparisons. Other officers have failed to show a similar relation between their organizations.28 At Camp Jackson, S.C., a group of organizations, carefully using boiling water in the washing of mess kits but composed of men of short service, showed a very much higher incidence rate during the fall outbreak than did another organization of much longer service that took no special care to effect thorough sterilization of dishes. Both used the dipping method.29 Here aparently the element of length of service was far more important in determining mobidity than was the sterilization of the mess kits.
Special bacteriologic experiments conducted at Camp Meade, Md., showed that, even when relatively cool, the soap in the dishwater was sufficient to kill the usual organisms found in respiratory infections, such as the pneumococci
and streptococci.30 these experiments, however, did show the possibility of the transference of organisms of the colon group by this means. As far as the influeza virus is concerned, the results are entirely inconclusive, as the exciting agent of this disease is not yet definitely recognized.
The consensus of opinion, based on the experience of the epidemic, would seem to be that while the rôle of the hand in the direct and indirect transmission of respiratory disease should receive careful study and fullest consideration, the claim that this reprseents the major avenue of spread of theese diseases can hardly be regarded as proved, and attention to this possible means of travel of the virus should not be allowed to draw attention from methods of prevention based on the more usually accepted theories of the method of transmission.
in spite of all evidence pointing to the importance of contact, attempts to transmit the disease experimentally under controlled conditions have uniformly failed. The United States Public Health Service sponsored two experiments of this character during the fall outbreak in 1918.31 One experiment was carried on in Boston, with 100 volunteers from the Navy, of the most susceptible age. None were known to have had influenza previously. These men were treated with influenza bacilli, with nasopharyngeal secretions, with and without filtration, by intranasal sprays, and by direct swabbing from patient to volunteer. The attempt was made to induce the disease by the injection of citrated blood from patients and the injection of filtrates of nasophyaryngeal secretion. Finally these men were exposed to the most intimate personal contact with patients in wards, all with the complete failure to produce the disease. A similar experiment was conducted with the same result in San Francisco. The explanation of this result is lacking. either the proper method of transmitting the disease was not used, which seems very unlikely in view of the diversity of methods employed, or the volunteers themselves were immune to the disease either naturally or through previous infection in spite of their negative history. This latter hypothesis is hardly satisfactory though seemingly more probable than the former.
It can only be said then that the experience of the war has confirmed our pervious belief that influenza is carried by infected persons and not for any distance through the air. The exact means by which the virus is transmitted from person to person, as well as the usual portal of entry in each case, remains unknown. While other means of transmission can not be excluded, and doubtless play their part, the known facts are not inconsistent with the generally accepted idea that the secretions of the respiratory tract expelled into the air by the act of coughing and inhaled by susceptible person in the immediate neighborhood constitute the most important route.
As to the duration of the period of infectivity of the individual case, no reliable deductions may be made. The negative attempts at transmission experiments already quoted suggest the possibility that the infective period is very short, possibly even limited to the period of incubation or invasion. This idea is also supported by the observation that different methods adopted by different commands in the handling of their influenza cases apparently produced little effect on the incidence of the disease. Some camps attempted
the immediate hospitalization and isolation of all suspicious cases, others reserved their hospitals for the seirously ill only, leaving the lighter cases for treatment in regimental infirmaries or in quarters where opportunities for transmission to the uninfected would appear to be much more numerous. It is not possible to show that this latter method of handling the situation resulted in any increase in the relative number of cases. The possible explanation may lie in a very brief period of infectivity, limited to the period of invasion or the earliest hours of the demonstrable presence of the active disease.
25. Lynch, C. and Cumming, I.G.: The Rôle of the Hand in the distribtuion of Influenza Virus, and the Secondary Invaders. The Military Surgeon, 1918, xlii, 597; also, The Journal of Laboratory and Clinical Medicine, St. Louis, 1918, v, 364.
26. Blanton, W.R., and Irons, E.E.: A Recent epidemic of Acute Respiratory Infection at Camp Custer, Michigan. The Journal of the American Medical Association,1918, lxxi, No. 24, 1918.
27. Vaughan, W.T.: Monograph No. 1. The American Journal of Hygiene, 1921.
28. Jackson, Thomas W.: The Other Side of the Question of Indirect Contact Infection in Acute Respiratory Diseases. The Military surgeon, Washington, 1920, xlvi, No. 5, 570.
29. Hall, Milton W.: A Note on the Epidemiology of Influenza. The Military Surgeon,I Washington, 1920, xlvi, No. 5, 564.
30. Nichols, H.J.: Bacteriologic Data on the epidemiology of Respiratory Diseases in the Army. The Journal of Laboratory and Clinical Medicine, St. Louis, 1920, v. 502.
31. Rosenau, M.J.; Keegan, W.J.; Goldberger, J.; and Lake, G.C.: Some Interesting Though Unsuccessful Attempts 6to Transmit Influenza experimentally, Public Health Reports, 1919, xxxiv, No. 2, 33. Also, McCoy, G.W., and richey, De Wayne: San Francisco Experiments. Public Health Reports, 1919, xxxiv, No. 2, 34.