Annual Report of the Secretary of the Navy, 1919 -- Miscellaneous Reports.
The Incubation Period of Influenza
Numerous reports indicate that the period of incubation was 48 hours or less in cases where the time and place of exposure could be fixed with reasonable certainty. No report furnished evidence that the incubation period was greater than 48 hours but the possibility of longer periods can not be ruled out.
In the receiving ship at Norfolk, Va., (St. Helena), among 962 cases of influenza close observation indicated that the period of incubation varied from a few hours to two days.
At the United States Naval Hospital, Chelsea, Mass., the first cases from the first outbreak in Boston at Commonwealth Pier (the receiving ship), were admitted to hospital on Thursday afternoon, August 29, 1918. Blood counts, blood cultures, and throat cultures were made immediately by laboratory officers, one of whom developed influenza the following Saturday morning, and another medical officer who made the first physical examination was also attacked on Saturday.
While it is barely possible that both of these officers were exposed to a case of influenza several days before August 29 it is more probable that the disease developed from exposure on the latter
date. A chief pharmacist at the hospital whose duties had not previously brought him into contact with patients, accompanied an ambulance to Commonwealth Pier on that day and he developed influenza within 24 hours.
In Santiago, Dominican Republic, no case of influenza occurred among marines in barracks there until December 9, although seven cases had been reported among natives by December 5. A quarantine against the town was in force at this time. On December 9 an officer who had contracted influenza in Puerta Plata became ill and was quarantined in his house. On December 11, a mail orderly who had been in contact with this officer became ill but did not report at sick call. Forty-eight hours after the arrival of the mail orderly in barracks, 15 men sleeping in his immediate neighborhood developed influenza. A common drinking cup was in use at the barracks. Another instance where the immediate source of infection could probably be traced relates to the telephone operators. These men stood 4-hour watches. One of them developed influenza and then four others came down in quick succession, each in about 46 hours after the termination of his watch.
At the officer material school, Princeton University, the medical officer had an unusually good opportunity to note the length of the incubation period in a considerable number of cases where the time of exposure could be quite definitely fixed. He concluded that the incubation period was just about 48 hours in practically all cases.
The Causative Agent of Influenza
Those who have engaged in studying the bacteriology of influenza and influenzal pneumonia during the pandemic are almost unanimously agreed that the causative agent has not been discovered. The Pfeiffer bacillus, pneumococci of all types, hemolytic streptococci and green producing streptococci, as well as other microörganisms commonly found in the mouth and in discharges from the respiratory tract--staphylococci, micrococcus catarrhalis, bacillus mucosus and spirochaetes--have been isolated from the sputum and from lesions in the lungs in varying percentages of cases.
Pfeiffer bacillus.--It is unnecessary here to record in detail the frequency with which this microörganism was found. The technique for its isolation in pure culture was not sufficiently understood generally either by bacteriologists in the Navy or in civil life at the height of the autumn epidemics to justify comparisons between the bacteriological findings in different epidemics and in different localities. Some workers who failed to find the Pfeiffer bacillus at first were able to isolate it in practically all cases after they had been set right by those who had adopted a suitable technique. At some naval stations the bacillus was found in practically all cases of influenza--often early in the disease--and was isolated from the lung tissues in from 60 to 80 per cent of fatal cases of influenzal pneumonia. In a considerable percentage of such cases it was the only microörganism recovered. In a few instances it was found in blood cultures taken during life and in cultures from the meninges in cases of complicating meningitis. However, it was not found in all cases even by those who had demonstrated their knowledge of a reliable technique and some epidemics it was either absent or
seldom recovered. As described below, experimental attempts to produce the disease signally failed. Studies in immunity gave various results but furnished no evidence that a single strain was being recovered in different epidemics or even from different cases in a local outbreak. The ability to produce agglutinins was variable and frequently with the identical strain no agglutinins could be detected in the serum of patients from whose sputum the bacilli were isolated, even though they were found in large numbers and in phagocytic cells from the lungs. In many instances agglutinins could not be demonstrated in the serum of animals after thorough attempts to immunize them had been made. In instances where a serum would agglutinate its particular strain it not infrequently failed to agglutinate bacilli recovered from another case of influenza in the same local epidemic although agglutination would occur with a serum specific for the latter strain.
Altogether, evidence was furnished for the belief that many strains of the Pfeiffer bacillus were associated with the epidemic but that no strain predominated. It seems clear that the Pfeiffer bacillus as an early secondary invader took an important part in causing the lesions of mixed infection in many cases, as it probably did in the 1889,1890, 1891, and 1892 epidemics.
Pneumococci and streptococci.--No particular type of pneumonococci predominated in different epidemics and frequently the type recovered from pulmonary lesions in fatal cases occurring in the same epidemic varied. In some epidemics, notably those in battleships of the Atlantic Fleet and in stations in the vicinity of Norfolk, Va., pneumococci appeared to predominate as secondary invaders and to be responsible largely for the fatalities. In most epidemics both pneumococci and streptococci were found in cultures from the lungs, and frequently pneumococci of one or more types and streptococci were recovered together from the same case. Sometimes during a prolonged epidemic pneumococci were found in a high percentage of the fatal cases at one stage, and later were found infrequently while streptococci predominated. In other epidemics, notably those among naval organizations at Puget Sound, and in Seattle, Wash., a streptococcus appeared to be responsible almost altogether for the pneumonias. This appeared to be a single strain which tended to grow as a diplococcus and produced a moderate amount of green in cultures. Sometimes it caused hemolysis and sometimes it did not. It might easily have been confused at times with certain strains of Type IV pneumococci. It was probably the same microörganism as the coccus described by Mathers. Satisfactory evidence that there was but a single strain was not furnished.
The general conclusion which might be drawn from investigations carried on in many naval laboratories is that whatever the causative agent of influenza may be and the likelihood that the virus itself was primarily responsible for influenzal pneumonia as well as for the lesions in mild uncomplicated cases, hemolytic streptococci, a strepto-pneumococcus-like microörganism, the Pfeiffer bacillus, and pneumococci of different types were severally and collectively responsible to a large extent for the severity of complications in most of the fatal cases of the disease. It would appear altogether probable that without successful invasion by streptococci or pneumococci,
the infectivity of which had been greatly heightened under the existing conditions of war, the case-fatality rates associated with the 1918 autumn epidemics would have been no higher than in epidemics occurring during previous pandemics.
As bearing on the heightened virulence of the causative agent of influenza during a primary epidemic, and possible attenuation subsequently, the following study made at the marine barracks, Quantico, Va., is of interest:
Of the men admitted to sick list with a diagnosis of influenza during the first three weeks of the primary epidemic, 4.1 per cent died, while the case-fatality rate for cases admitted during the second three weeks was only 2.6 per cent. In the fifth week of the epidemic there were 3 deaths in 94 cases and these were in men who had recently arrived. In the sixth and seventh weeks 166 cases of influenza were admitted to hospital, with no deaths. Of this number about 100 were men who had recently arrived in good health, but subsequently contracted infection at Quantico.
It might be inferred from these facts that the microörganism which caused the epidemic at Quantico gradually became attenuated and that notwithstanding the introduction of susceptible persons from the outside the case-fatality rate was nil.
During the eighth week after the beginning of the primary epidemic the disease again became prevalent and the case-fatality rate rose suddenly to 6 per cent during the week ending November 4. Investigation showed that a draft of 958 men had arrived from Parris Island, S.C., on October 27, 1918, and that immediately upon arrival 50 cases of influenza were admitted to hospital from this draft.
Many other cases subsequently appeared. The draft may have brought with it a virulent strain of the causative agent which had not yet become attenuated. The following is an attempt to show this in tabular form:
|Total cases admitted||163||952||714||301||94||36||130||18||268||2,876|
|Quantico strain.||Parris Island strain.||------|
Modes of Transmission
may be assumed that the disease is highly communicable and that it spreads both by direct and indirect contact of healthy persons with patients. It may be that the virus is carried by healthy persons, but this can neither be proved nor disproved at the present time. Many of the cases of influenza are so mild that the infected individual is able to go about his business and is thus capable of spreading the disease.
Just after the crests of the earlier epidemics were reached two series of experiments were authorized by the Navy Department under arrangements made by the Bureau of Medicine and Surgery in cooperation with the United States Public Health Service for the purpose of determining, if possible, the mode of transmission of influenza as well as the causative agent.
Boston experiments.--These experiments were carried on jointly by Lieutenant Commander, M.J. Rosenau, Medical Corps, United States Naval Reserve Force, and Lieutenant W.J. Keegan, Medical Corps, United States Naval Reserve Force, and by Surgeon J. Goldberger and Assistant Surgeon G.C. Lake, United States Public Health service, at the United States Quarantine Station, Gallups Island, Boston, Mass. The subjects of experiment were 68 volunteers from the United States Naval Detention Training Camp, Deer Island, Boston. These volunteers had been exposed in some degree to an epidemic of influenza at the training camp or at some station prior to coming to Deer Island; 47 of the men were without history of an attack of influenza during the recent epidemic, and 39 of these were without history of an attack of such illness at any time during their lives.
The experiments consisted of inoculations with pure cultures of Pfeiffer's bacillus, with secretions from the upper respiratory passages, and with blood from typical cases of influenza. The study was begun November 13 with an experiment in which a suspension of a freshly isolated culture of Pfeiffer's bacillus was instilled into the nose of each of three nonimmunes and into three controls who had a history of an attack in the recent epidemic. None of these volunteers showed any reaction following this inoculation. Another experiment was made at a later date with a suspension of a number of different pure cultures of Pfeiffer's bacillus, of which four were recently isolated. Ten presumably nonimmune volunteers were inoculated with the same negative results.
Three sets of experiments were made with secretions, both unfiltered and filtered, from the upper respiratory tract of typical cases of influenza in the active stage of the disease. In these experiments a total of 30 men were subjected to inoculation by means of spray, swab, or both, of the nose and throat. The interval elapsing between securing secretions from the donors and inoculation of the volunteers was progressively reduced in these experiments, so that in the third of the series the interval at most was 30 seconds. In no instance was an attack of influenza produced in any of the subjects. An experiment was made in which the members of one of the groups of volunteers which had been subjected to inoculation with secretions were exposed to a group of cases of influenza in the active stage of the disease in a manner intended to simulate conditions which in nature are supposed to favor the transmission of the disease. Each of this group of 10 volunteers came into close association for a few
minutes with each of 10 selected cases of influenza in the wards of the United States Naval Hospital, Chelsea. At the time the volunteers were exposed to this infection the cases were from 10 to 84 hours from the onset of their illness and 4 of them were not over 24 hours after the onset. Each volunteer conversed a few minutes with each of the selected patients, who coughed into the face of each volunteer in turn, so that each volunteer was exposed in this manner to all 10 cases. The total exposure amounted to about three-quarters of an hour for each volunteer. None of these volunteers developed any symptoms of influenza following this experiment.
Advantage was taken of the opportunity for making this study to attempt to confirm the reported positive results of transmission of influenza by Nicolle. Secretions from five typical cases of influenza were secured, filtered, and some of the filtrate inoculated subcutaneously into each of a group of 10 volunteers. At the same time blood was drawn from the same cases and pooled, and some of the mixed blood injected subcutaneously into each of another group of 10 volunteers. The time lost between drawing the blood and inoculating it in no case exceeded three quarters of an hour. None of the men subjected to these inoculations developed any evidences of illness.
In the foregoing experiments the patients serving as donors belonged to groups from epidemic foci either on shipboard or at institutions. The great majority indeed belonged in a group from an epidemic on board the U.S.S. Yacona. Of the personnel of this vessel, 95 in number, 80 or 84 per cent, were stricken with the disease in an epidemic between November 17 and 29.
San Francisco experiments.--The following observations were carried out practically simultaneously with those described above. The work was done at the Angel Island Quarantine Station, San Francisco, Cal., utilizing volunteers from the Yerba Buena Naval Training Station, San Francisco. The experiments were carried on jointly by Surgeon G.W. McCoy of the United States Public Health Service, and Lieutenant De W.G. Richey, Medical Corps, United States Naval Reserve Force. The volunteers who were used in these experiments differed from those used at Boston in two respects--first, the personnel of the Yerba buena staton had not been exposed to influenza in the present epidemic and were therefore presumed not to possess any special natural immunity; second, all of the men had been vaccinated with large doses of a bacterial vaccine containing Pfeiffer's bacilli, the three fixed types of pneumococci and hemolytic streptococci. It is impossible at present to state what influence this vaccination may have had in promoting resistance to influenza infection, but to judge by the results of controlled experiments, elsewhere such vaccinations may for the present purpose be ignored.
Brief details of the experiments are as follows:
Work with cultures.--A group of 10 volunteers was divided into two equal squads. One group had instilled into the nostrils of each man a heavy suspension made by emulsifying cultures of eight strains of Pfeiffer's bacillus without filtration. The other group had the same material used after passage through a Berkefeld N-candle. The results were negative, though the men were held under observation for seven days.
Work with secretions.--Four groups of volunteers, of 10 men each, were used for these experiments. Emulsions of secretions from the upper respiratory passages of active cases of influenza from 15 to 48 hours from the onset were instilled into the nose by means of a medicine dropper, or with an atomizer. In each experiment approximately an equal number of volunteers were treated with the same emulsion after filtration through a Berkefeld N-candle. In every case the results were negative, so far as the reproduction of influenza is concerned. The men were all observed for seven days after inoculation. In three cases in which unfiltered material had been instilled sore throat developed which corresponded clinically with acute tonsillitis, and in two of these cases an almost pure culture of a hemolytic streptococcus was secured from throat cultures.
A filtered emulsion of material from the upper air passages of an acute case of influenza was dropped into the conjunctivae of two volunteers and the same material injected subcutaneously into one volunteer. In each case the result was negative.
One cubic centimeter of blood taken during the active stage of influenza was inoculated subcutaneously into one volunteer with negative results.
In all of these experiments the time between the collection of the material from the patient and its inoculation into the volunteers was in the neighborhood of three or four hours. The conditions under which it was necessary to conduct experiments did not permit a shorter interval. The unfiltered suspensions which were used were submitted to cultural examination after inoculation and found to contain living organisms as follows: Pfeiffer's bacillus, pneumonococci of Group IV, and hemolytic streptococci.
Unfortunately, although performed with the utmost care upon a large number of volunteers, none of these experiments furnished any conclusive evidence in spite of the fact that attempts to transfer the disease were made in the freest possible manner. However, the results obtained in these studies certainly seem to invalidate the conclusion reached in previous filtration experiments in which controls had not been thought necessary.
The outstanding facts are that all attempts to transfer the disease from patients ill with influenza in the acute stages, from 10 to 84 hours from the onset of symptoms, failed. The direct exposure of volunteers in the hospital ward, each volunteer to several influenza patients, thus affording opportunity for transmission of the disease by what has been presumed to be the natural and usual method of dissemination, as well as the promptness with which fresh moist secretions were transferred from patient to volunteer, and the precaution to make subcutaneous inoculations with pooled blood and pooled nose-and-throat secretions from patients acutely ill would appear to leave little to be desired in respect to the completeness with which this research work was performed. Further attempts were made later in Boston to secure more conclusive results by obtaining secretions from patients in the very early stages of the disease, but these subsequent experiments led to findings which were scarcely more definite than those described.
Negative as the results of these experiments were the work itself was of the utmost importance and it serves well to check the generally
entertained belief that the transmission of an acute communicable disease of the respiratory type is a very simple matter. While the transfer of the causative agent of such a disease from one individual to another may reasonably be assumed to take place commonly by means of the "droplet spray" directly, as well as indirectly, by means of a freshly contaminated article, such as a drinking utensil or by the fingers which have touched a contaminated article, it is nevertheless probable that immunological conditions play a most important part and that the time of exposure has a determining influence as well as the duration of exposure, the immunological state of the patient (aggressiveness of the causative microörganism) and the immunological state of the person exposed. From the results obtained in these efforts to transmit the disease, influenza especially would appear to require particular conditions for its transmission and yet the gross epidemiology of the disease indicates that it is highly communicable and spreads promptly wherever it is introduced.
Practically all persons who have not had influenza appear to be susceptible to an attack although not necessarily a severe one. Perhaps a majority of those who had the disease in previous years experienced an attack in 1918, if not in severe form at least as a transient mild infection. On the other hand, as pointed out above, many persons in the Navy who had influenza in mild form during the spring months escaped an attack in the autumn of 1918, although there were also many exceptions.
It was reported from the U.S.S. Nashville that cases which developed during the autumn epidemic in the United States were even milder than those which occurred during the spring and summer in European waters. All new cases developed in men received on board after returning to the United States. No man who had had the disease in Europe was attacked.
In the Seventh regiment of Marines, stationed at San Juan, Santiago de Cuba, during a recurrent epidemic of influenza it was observed that the Ninety-third Company suffered heavily. During the primary epidemic the greatest number of cases occurred in the Seventy-first and Fifty-ninth and but few cases occurred in the Ninety-third Company, although it was camped immediately alongside the others. During the recurrence few cases occurred in the other two companies. Several instances of second attacks of influenza in the same individuals were noted, but not in severe or serious form.
With regard to a recurrent outbreak of influenza which occurred at the United States Naval Training Station, Great Lakes, Ill., the following interesting observations were made:
Following the receipt of men from Camp Logan and from the receiving ship at Philadelphia, Pa., after the primary epidemic had passed, both of these stations also having passed through epidemics, there was no noticeable increase in the incidence of influenza at the Great Lakes Station and it was assumed that the new arrivals, who were presumably immune in both instances, either did not bring infection with them or that the station force was also immune by reason of the recent epidemic. On October 27 and October 30 recruits were received from the cities of Atlanta, Meridian, Richmond, Baltimore, Pittsburgh, Nashville, Louisville, and New Orleans. Following their arrival a second outbreak of influenza occurred at the station on November 2, lasting until November 9. During this period 200 cases of influenza occurred, but the disease was
confined entirely to recruits from the above-mentioned cities, none of whom had been in camp over five days when attacked, and many were taken ill on the train before arrival. The fact that men who had been on the station for a longer period did not take the disease would indicate immunity.
In the receiving ship at Norfolk, Va., it was noted that only two cases of influenza occurred among the many negro mess attendants quartered on the station during the epidemic.
On the whole it may be concluded that immunity to some degree is conferred by an attack in most instances, but statistics so far have failed to furnish definite knowledge as to the duration of such immunity. It is noteworthy that influenza in the past has recurred in a community year after year for several years in epidemic form following a pandemic, in spite of the fact that from 20 to 30 per cent of the population was attacked during the primary epidemic. It is difficult to believe that some at least of the young adults who developed influenzal pneumonia and quickly succumbed to this complication had not had influenza in a previous year.
Epidemiological studies in civil life indicate that the highest incidence during the fall epidemics was among children and adolescents who, presumably, represented the age groups least likely to have been exposed in previous years. The incidence curve declined steadily through age groups beyond 35, yet no age group proved immune. The children frequently had very mild attacks and epidemic death rates among adolescents and children of school age seem to have been remarkably low. The general death rate among very young children and infants under one year was high during the epidemic, but how many of the deaths were actually due to influenza infection is not yet clear.
The medical world should appreciate the spirit and bravery of the men of the Navy who eagerly subjected themselves to experimentation for the welfare of humanity, for they were warned specifically and they had every reason to believe, as did those who conducted the research work, that they were risking their lives. These volunteers have indeed rendered service to their country and to the world, and the fortunate circumstance that none was seriously harmed does not detract from the significance of this exhibition of high personal courage and of the willingness displayed by all of them to sacrifice themselves for others.
Following is the list of men who volunteered during the Boston experiments:
Abney, Dewey Lavern.
Allan, Robert Andrew.
Anderson, Arthur Raymond.
Bolduc, Joseph Real.
Bullock, Muro Chester.
Calabrese, James Joseph.
Center, Edward Thomas.
Crowley, Henry Edward.
Denaard, Arthur Frederick.
Edman, Charles Frederick.
Englert, Henry Joseph.
Felton, James Elwyn.
Fleming, George William.
Fournier, Ernest Joseph.
Garriott, Simon George.
Gerow, Percy Hector.
Gibson, Edward Molten.
Healy, Thomas B.
Hedges, Daniel Judd.
Kearney, Eugene Aloysius.
Malone, Walter James.
Maas, Paul Alfred.
Morrell, William Francis.
Murphy, Leonard Richard.
Murphy, William Joseph.
McAnneny, John Henry.
McKenna, Joseph Edward.
O'Toole, Frank Codman.
Peak, George Francis.
Reid, Robert Lincoln.
Scott, Robert James.
Stanton, Judson Horatio.
Vandermeer, John William.
Vanelli, Arthur Nicholas.
Veteto, Gus Robert.
Vieira, Leopold Joseph.
Wanless, Frank B.
Heine, John Joseph.
Hill, Warren Arthur.
Holmes, Harrison Stephen.|
Aimar, Bertram Hillard.
Dawson, Harvey Allen.
Fink, Herbert Jacob.
O'Neill, Nick Persian.
Evans, Hugh John.
Holziner, Carl Peter.
Warren, Robert Flagg.
Whipp, Raymond Calvin.
Hickey, Edward John.
Jones, Orlando Lloyd.
Lang, William Norman.
Campbell, Verlin Everett.
The following men volunteered for the experiments at San Francisco:
Leggett, James Verna.
Oldham, George W.
Eagan, Estis Theodore.
Harrell, Lewis Roy Kendall.
Toombs, Herbert Edgar Lawrence.
Thomas, Franklyn Forrest.
Bennett, J.C., jr.
Combs, Lester Robert.
Mulcahey, Daniel Vincent.
Taylor, Christopher Anthony Lester, Roy.
Le Duc, Antonio Oliver.
Wall, Lewis Edward.
Lind, Clifford Charles.
Crane, Ellis Madison.
Thompson, Arthur Eugene.
Alsott, Charles Benson.
Tomlins, Roy Lee.
Miller, Frank A.
Dulaney, Floyd Marcue.
Eskew, Herman Virgil.
Shankle, John Swanson.
Tharp, Robert Herman.
Autry, Chalie Lester.
Casson, Jesse Meredity.
McLaughlin, Joseph Francis.
Lorenz, Joshua H.
Hickson, Samuel Dewey.
Morrow, Ernest James.
Stephenson, Neato Augusta.
Dickenson, Lester William.
Bennett, Ray Ernest.
Howard, Fred Elmer.
Christian, Lester O.
McGaughy, Oscar A.
Callison, George A.
These included quarantine, daily inspection of personnel and the taking of temperatures, early isolation of the sick, the wearing of face masks and gowns and rigid aseptic technic by attendants upon the sick; the early transfer of patients to a base hospital; the retention and isolation of patients in dispensaries where they could be segregated in small groups instead of being brought into immediate or indirect contact with large numbers of other patients; strict attention to ventilation, relief of overcrowding, use of muslin screens between bunks or hammocks in barracks; prevention of gatherings indoors as much as possible; restrictions on travel, particularly by common carrier;
the application of nose and throat sprays to those not yet attacked; the use of prophylactic vaccines, the very general and intensive use of educational measures, and the rigid enforcement of sanitary rules and regulations with particular regard to personal hygiene, cleanliness, care of floors and decks, windows, and other ventilating inlets and outlets, mess gear, drinking utensils, drinking fountains and other articles liable to contamination with mouth and nose discharges of patients or carriers. The protection of influenza patients during convalescence, even those having mild attacks, was generally regarded as an important preventive measure. The therapeutic use of serum donated by patients convalescing from influenzal pneumonia was given a somewhat extensive trial in attempts to reduce influenzal pneumonia case-fatality rates.
Speaking in general terms, the history of influenza in the autumn of 1918 shows that the disease spread rapidly and progressively, attacking communities of all sizes regardless of preventive measures put into effect, and regardless of geographical location, climate, weather, nature of the industries, race, density of population, habits of the people, character of housing, habits of diet, social and economic conditions, sanitation, soil conditions, flora and fauna, or routes and modes of travel.
Naval stations varied greatly in size and density of population as well as with regard to geographical location, environment, and the nature of activities carried on. Strong efforts were made at all stations and on board all vessels to prevent the introduction of the disease and to limit its spread by the enforcement of all preventive measures which were practicable under war conditions. Attention was paid universally to sanitation, education of the naval personnel, ventilation, proper care of mess gear, and early treatment of the sick. Relief of overcrowding was possible in some places; in others, not. Under the necessity of fighting the war it was usually deemed impracticable to establish quarantine of any degree or to prevent intercommunication with civil communities and other naval stations. At different stations various special preventive measures were tried, such as vaccines, use of face masks, daily or twice daily use of prophylactic nose and throat sprays, and putting the men into tents.
Epidemic incidence rates, epidemic death rates, and case-fatality rates varied considerably at different shore stations and among different forces afloat, as the statistical data show. Not infrequently certain specific measures which were credited at one station with having prevented the spread of influenza or with having reduced the complications or with having kept case-fatality rates low failed to prove of any value at another station. So many epidemiological factors were or might have been involved in every instance that it is quite impossible to judge what factors were operative at a given station or to what preventive measures low rates could be definitely attributed when they occurred. It may be said, however, that each of the preventive measures enumerated was thoroughly tried, in conjunction with other measures of course, at some one or more stations where the incidence of influenza was high and the epidemic severe. In other words, each particular preventive measure failed in some instances to accomplish recognizable results.
It should be remarked that influenza was regarded as a disease of the respiratory type disseminated by moist discharges from the
mouth and nose, and the preventive measures applied were those which have come to be looked upon as valuable in preventing the spread of any acute communicable disease of the respiratory type. With the exception of absolute quarantine at the United States Naval Training Station, San Francisco, these measures proved of little or no appreciable value in the presence of epidemic influenza.
The experience of 1918 would indicate that a very important preventive measure when confronted with an outbreak of influenza consists in rapidly enlarging existing medical and nursing facilities for the proper care and treatment of the large numbers of persons who will inevitably be attacked regardless of measures planned to prevent the occurrence or spread of the disease.
Quarantine.--Absolute quarantine was imposed at the United States Naval Training Station, San Francisco, on September 23, before the introduction of influenza. All officers, enlisted men, and civilian were recalled and required to remain on the island. All communication with San Francisco and Oakland was discontinued, except to receive supplies and recruits or other men who reported and necessarily had to be received. Precautions were taken to prevent the crews of tugs from approaching persons on the dock closer than 20 feet. All recruits and others who had to be received from the mainland had the pharynx and nasal passages thoroughly sprayed with a 10 per cent solution of silvol and were required to put on gauze face masks before they were allowed to board the tug bound for the island. Upon arrival they were placed in a quarantine camp for several days, during which they wore masks, were sprayed three times a day with silvol, and were required to keep at a distance of 20 feet from each other.
The entire personnel of the station--officers, enlisted men, and civilians were required to have the pharynx and nasal passages sprayed once daily with a 10 per cent solution of silvol. All drinking fountains were flamed with a gasoline torch, and all telephone transmitters were disinfected twice daily. In barracks each cot was provided with a muslin screen extending around the head and along one side, 30 inches above the level of the cot. A part of the personnel was quartered in tents. Outdoor recreation was provided.
This was not a pure quarantine experiment. The entire personnel was inoculated with three successive doses of a mixed bacterial vaccine administered October 12, 15, and 18, respectively. This vaccine contained per c.c.:
|Pfeiffer bacillus, Rockefeller strain||5,000,000,000|
|Pneumococcus type I, various strains||3,000,000,000|
|Pneumococcus type II, various strains||3,000,000,000|
|Pneumococcus type III, one strain||1,000,000,000|
|Streptococcus hemolyticus, two strains||100,000,000|
The three doses were 0.5 c.c., 0.8 c.c., and 1 c.c. respectively.
While quarantine was in effect no case of influenza occurred on the station, although all other naval stations on the Pacific coast, as well as civilian communities, experienced epidemics during this period. The disease made its first appearance at the station on December 6, 16 days after quarantine was raised.
In the city of San Francisco the primary epidemic began during the week ending September 21, reached its height during the week ending October 5, and subsided rapidly. The epidemic, as indicated
by epidemic death rates, was of about the same duration and severity as those which occurred in Boston, Mass., and Washington, D.C., in spite of the fact that somewhat drastic ordinances and regulations, which included the compulsory wearing of face masks on the street, were adopted; measures which the cities in the East did not see fit to undertake. A rather sharp recurrent epidemic began in the city during the week ending December 14, and the weekly death rate did not reach an approximately normal level until after the week ending March 8, 1919.
At the United States Navy Yard, Mare Island, Cal., very practical precautions were taken as early as September 23, against the introduction and spread of the disease. Absolute quarantine was not feasible but a modified quarantine was ordered. The epidemic in the Mare Island navy yard began October 4, and reached its height in the latter part of the month. The incidence diminished one half in November, but the epidemic period lasted until November 30.
To the absolute quarantine efficiently maintained on Goat Island must be attributed the entire absence of influenza from this training station while all communities in the vicinity were suffering. After free communication was resumed with San Francisco and Oakland on November 21 the disease was introduced, and during the month of December 148 cases of acute bronchitis, 13 of broncho-pneumonia, 4 of lobar pneumonia, and 25 cases of influenza were reported. Doubtless some at least of the cases reported as broncho-pneumonia were true cases of influenza, and judging from the incidence of pneumonic complications at other stations it is altogether probable that at least 100 cases of influenza occurred. The experience at this station seems to show that under exceptional conditions quarantine can be made effective against the introduction of influenza, but that after quarantine is raised the disease will make its appearance with an incidence proportionate to that obtaining at the time in the surrounding territory. Beyond question, life was saved there by the absolute quarantine.
Deaths from influenza and all forms of pneumonia, during the year 1918, occurred at the United States Naval Training Station, San Francisco, as follows:
|Apr. 4||------||1||Oct. 15||------||------|
|July 7||------||1||Dec. 4||------||1|
|Aug. 21||------||1||Dec. 22||2||1|
|Aug. 28||------||1||Dec. 28||1||------|
Unfortunately for epidemiological purposes, the issue was clouded by the fact that the entire personnel received three doses of mixed bacterial vaccine. It is possible, even probable, that such a vaccine would reduce the percentage of pneumonic complications and case-fatality rates in so far as due to secondary invasion by the microörganisms represented, but the evidence adduced elsewhere indicates that the vaccine would not protect against influenza. This was the experience at the marine barracks, Parris Island, S.C.; at Quantico,
Va.; at the United States Naval Training Camp, Pelham Bay Park, N.Y., and at the United States Naval Training Station, Great Lakes, Ill. Moreover, among 200 men received at the United States Navy Yard, Mare Island, in a draft from the United States Naval Training Station, San Francisco, at 9 p.m., December 5, three of them were found ill with influenza at 8 a.m., December 6, and during the evening of the same day three additional cases were discovered. On the following day 16 cases developed, making a total of 22, or 11 per cent of the draft, attacked in about 48 hours. This is of interest in connection with the San Francisco experiments discussed on page 422.
It was the opinion of medical officers at the station that spraying of the nose and throat could be eliminated as preventing the disease, because it was used before, during, and after the appearance of influenza cases.
A modified quarantine was imposed at many naval stations. Invariably this measure failed to prevent the introduction of influenza. Influenza proved to be so highly communicable that nothing short of absolute quarantine appeared to have any effect whatever upon the incidence of the disease. At some stations where liberty was restricted and communication with outside sources was reduced to a minimum the epidemic was severe and the attack rate high, while other stations where similar measures were adopted escaped lightly.
The United States Naval Training Camp at Pelham Bay Park furnished an example of the apparent futility of preventive measures in influenza. This station was planned and built in accordance with modern ideas along the lines of preventive medicine. The barracks were comfortable and well ventilated and the men were quartered in comparatively small units. There was a well appointed and well administered detention camp, with separate dispensaries and mess halls. A modified quarantine was in effect at the station. In spite of this the attack rate, the epidemic death rate, and the case-fatality rate were all considerably higher than at the Federal rendezvous, a large armory in a thickly settled section of Brooklyn, N.Y., where the complement was constantly shifting, and where the crew of 1,700 men was berthed in a single large room. No restrictions whatever were imposed on visiting and liberty, because it was not practically to do so. According to all the tenets of epidemiology this station should have suffered worse than the training camp at Pelham Bay Park, situated at the extreme edge of the city limits in a more or less isolated position.
Vaccines.--Experiments in prophylaxis were conducted at various naval stations almost from the beginning of the severe epidemics in the fall of 1918, with vaccines made from pure cultures of the Pfeiffer bacillus; with hemolytic streptococcus and with mixed vaccines containing the three fixed types of pneumococci and several strains of Type IV pneumococci with or without streptococci or Pfeiffer bacilli. Experiments with the Pfeiffer bacillus lead to the conclusion that no protection against influenza was afforded by bacterins prepared from strains of this mircoörganism recovered from the lungs in cases in influenzal pneumonia. Altogether, many thousands of men were vaccinated, with the inevitable result that much conflict of opinion arose from the fact that many individual vaccinated were not subsequently attacked by influenza. Unless properly
controlled, vaccination experiments were without value. In the following instances controls were used: Five hundred and fifty-four men in the "incoming detention camp: at the training camp, Pelham Bay Park, N.Y., were given three inoculations of a Pfeiffer bacillus vaccine prepared at the United States Naval Hospital, Chelsea, Mass., and administered in three successive doses, 0.5 c.c., 1 c.c., and 1 c.c. of a well clouded but not counted bacterin. The third inoculations were completed October 5, 1918. On October 10, the 554 inoculated men, together with 800 controls, who had also been held in the incoming detention camp, were released into the main camp. At the time of their release the incidence of influenza in the main camp was decidedly on the decrease and opportunity to contract infection was less than at the height of the epidemic. Nevertheless, 50, or 9 per cent, of the vaccinated men contracted the disease, while only 40, or 5 per cent, of the controls became infected.
Several thousand men were vaccinated at the marine barracks, Parris Island, S.C., in the latter part of October; some with a Pfeiffer bacillus vaccine prepared at the United States Naval Laboratory, Philadelphia, Pa., and some with a similar bacterin which included strains of the Pfeiffer bacillus recovered from patients in the United States Naval Hospital, Chelsea, Mass., prepared at the Hygienic Laboratory, Washington, D.C. Many of the men inoculated were transferred overseas shortly afterwards, and their subsequent histories could not be ascertained. However, a draft of 756 men transferred from Parris Island, S.C., in the early part of November came under observation at the marine barracks, Quantico, Va. Of these, 304 had not been vaccinated, and 39, or 12.8 per cent, contracted influenza within a week after arriving at Quantico. Four hundred and fifty-two men of this draft had received from one to four inoculations of Pfeiffer bacillus vaccine while at Parris island, and 72, or 15.9 per cent, contracted influenza as follows:
After one inoculation, 11 of 75 men (14.6 per cent) contracted influenza.
After two inoculations, 30 of 226 men (13.2 per cent) contracted influenza.
After three inoculations, 8 of 57 men (14.0 per cent) contracted influenza.
After four inoculations, 23 of 94 men (24.4 per cent) contracted influenza.
A study of the severity of the disease in those not vaccinated, in comparison with those who had received vaccine, indicated that vaccination had no marked influence upon the course and severity of the attack. This conclusion was based on observation of 200 cases of influenza in men who had recently arrived from Parris Island, S.C. The findings were as follows:
|Number of cases with no prophylactic inoculation||92||
|Number of cases with one inoculation||29||
|Number of cases with two inoculations||40||
|Number of cases with three inoculations||9||
|Number of cases with four inoculations||30||
|Total number of cases||200||
|With vaccine prophylaxis||57||
|With vaccine prophylaxis||44|
|With vaccine prophylaxis||11|
Observation of 281 influenza patients treated in the United States Naval Hospital, Philadelphia, Pa., between October 6 and October 29, 1918, 60 of whom had previously been vaccinated with Pfeiffer bacillus bacterin and 221 not, seemed to show that the incidence of pneumonic complications was decidedly lower in the vaccinated cases. No trustworthy evidence was presented that Pfeiffer bacillus vaccine had any value as a therapeutic agent.
A streptococcus vaccine was used extensively in the thirteenth naval district where responsibility for pulmonary complications and deaths was attributed principally to the microörganism from which the bacterin was prepared. At first regarded as an ordinary hemolytic streptococcus this microörganism was later found to have characteristics similar to those of the Mathers coccus as mentioned above in reference to microörganisms associated with influenzal pneumonia.
The following table indicates the results obtained by the use of this vaccine which was prepared from microörganisms isolated from the blood of living patients and from the tissues in fatal cases. Cultures were nearly always pure. The microörganism could be obtained from the sputum of almost any case and was practically always found in the lung tissues at post-mortem examination. The microörganism easily lost its virulence and hemolytic properties in subculture at 37 C.. and was sometimes indistinguishable from the diplococcus. Proof that there was but a single strain was not furnished and it is not unlikely that the vaccine contained more than one strain. Three doses were administered 48 hours apart, 0.5 c.c., (250,000,000), 1 c.c. (500,000,000, and 1 c.c. (500,000,000).
|Seattle Training Camp No. 1||------||4,159||------||813||------||19.5||------||33||------||4.0|
|Seattle Training Camp No. 2||662||------||11||------||1.60||------||0||------||0||------|
|Seamen's barracks, Puget Sound||2,800||3,472||57||428||2.03||12.3||0||42||0||9.8|
|Marines, Puget Sound Navy Yard and ammunition depot||425||------||5||------||1.2||------||0||------||0||------|
It should be said that no unit was divided into two parts for the purpose of running experimental subjects and controls side by side. Circumstances did not permit. In the largest unit (seamen's barracks)
many cases of influenza had already occurred before vaccination could be performed; how many is unknown. The same is true of the draft from Philadelphia, but not of the rest of the command.
Conditions of exposure were not materially different in the different units. Housing conditions differed in that some men were in barracks and some in tents, but this seemed to have no effect upon the incidence of the disease. All of the marines were in barracks, rather closely quartered. All of the Seattle Training Camp men were quartered in tents, two men to a tent (8 by 10).
Of 4,212 men who were vaccinated not one man died. Among 111 Filipinos isolated and vaccinated early, and later exposed, there occurred only 2 cases. Among 361 marines vaccinated early, with no attempt to control exposure, there occurred 2 cases, both patients coming down after the first injection. Among 62 marines at the ammunition depot who were vaccinated early there occurred 3 cases--2 after the first injection and 1 after the third. Among 662 sailors at the Seattle training camp, 3 men developed the disease after the first injection, 1 after the second injection, and 7 after the third. Among 83 of the aviation corps there occurred 32 cases, 31 of the patients coming down within a few hours after the first injection and 1 after the third injection. Thus, altogether there were 1,279 men who were vaccinated either before exposure or about the time they were exposed, and of these, 94 developed the disease before vaccination was completed, and 11 afterwards. All recovered. Some of the cases in vaccinated men were fairly severe, and from the blood of one of these patients the diplo-streptococcus mentioned was recovered.
The period of observation was from September 17 to October 21, 1918. Up to November 3, there had occurred but 40 additional cases at the Seattle training camp and 16 at the Puget Sound navy yard, facts which seem to indicate that the epidemic was practically over at the time these data were obtained.
Mixed vaccines were tried at several different stations, but satisfactory controls were not used and war conditions made it impossible to keep track of many of the men vaccinated. The same is true of men inoculated with vaccine composed of the three fixed types of pneumococci. The use of a mixed vaccine at the United States Naval Training Station, San Francisco, Cal., while the station was under absolute quarantine has already been mentioned.
Face masks.--The wearing of face masks by healthy persons was made compulsory at several stations and on board a few vessels. On the whole this was not a practicable measure and little or no good was accomplished by the use of masks. The eyes were not protected. The masks quickly became soiled and required frequent adjustment by the fingers.
Reference has already been made to the three naval air stations in the third naval district, where masks were worn. The attack rates and epidemic death rates were comparatively high at two of them and at the third an epidemic had occurred in the spring.
On board one of the transports all troops and the entire crew were required to wear masks throughout the trip to Europe. The incidence of influenza was very low during the trip and this was attributed by the medical officer very largely to the wearing of masks.
However, other transports in the convoy, sailing from the same port at the same time also had very little influenza on that trip without resorting to masks, although the incidence had been high during the previous trip.
No evidence was presented which would justify compelling persons at large to wear masks during an epidemic. The mask is designed only to afford protection against a direct spray from the mouth of a carrier of pathogenic microörganisms; and assuming that it affords such protection, the probability that the microörganisms will eventually be carried into the mouth or nose by the fingers is very great if the mask is worn for more than a brief period of time. Masks of improper design, made of wide-mesh gauze, which rest against the mouth and nose, become wet with saliva, soiled with the fingers, and are changed infrequently, may lead to infection rather than prevent it, especially when worn by persons who have not even a rudimentary knowledge of the modes of transmission of the causative agents of communicable diseases.
On theoretical grounds it is good practice to require those who visit, examine, or wait upon the sick to wear masks. The experience at the United States Naval Hospital, New London, Conn., was typical of that encountered at several other hospitals. "Face masks were worn constantly by medical officers, nurses, and hospital corpsmen while they were in the wards." "The morbidity rate, nevertheless, was very high among those attending the sick, and our experience indicates that if the mask has any value it is simply in preventing an overwhelming dose of infection from direct coughing or other acts accompanied by forcible expulsion of nose and throat secretions." :While it may be taken for granted that masks should be worn by medical officers, nurses, and hospital corpsmen in handling the sick, our observations lead to the opinion that the use of masks in barracks is not a practicable measure of value under ordinary routine conditions." "The very high infectivity of this disease was demonstrated by results in our contagious annex, which is a building especially constructed for the care of communicable disease." "During the past four months patients ill with such diseases as cerebro-spinal fever, diphtheria, measles, mumps, scarlet fever, and German measles have been treated in this building." "Upon occasion, all of these different diseases have been handled at the same time, and the patients have been subsisted from the same diet kitchen, and yet there has been no instance of cross infection." "It may therefore be concluded that the technique was satisfactory; nevertheless, it failed to prevent cross infection in the case of influenza." "A number of medical officers and nurses were infected in that building, and the incidence of the disease was just as high there as in the improvised wards."
At the United States Naval Training Station, Great Lakes, Ill., of 674 hospital corpsmen and volunteers of other ratings who were on duty caring for the sick during the epidemic, 96 wore gauze masks. The others did not. Of the latter, 7.9 per cent developed influenza, while 8.3 per cent of those who wore masks contracted the disease. It will be noted that the attack rate in both groups was much lower than for the personnel in general at the station.
Prophylactic nose and throat sprays.--Nose and throat sprays of various kinds were used at several stations and on board many
vessels, not only as a measure applied to the entire personnel in an attempt to prevent the introduction of influenza, but also to check its spread. Those who made use of sprays in a comprehensive way usually felt that good results were accomplished, but comparative statistics do not show this. So many epidemiological factors were operative in all cases and so many preventive measures were tried in addition to spraying that no definite conclusion can be reached from a review of the evidence as to whether or not any great value can be attached to the use of sprays.
At the navy yard, Philadelphia, Pa., an oil-camphor-menthol spray apparatus was installed in the machinery division and a man was kept on duty constantly to spray the nose and mouth of each employee every two hours. The results were reported as satisfactory beyond expectation. "Only two out of a thousand men contracted the disease." Two grains each of camphor and menthol to 1 ounce of liquid petrolatum was used. The liquid petrolatum was regarded as poor culture material, and furthermore it did not wash out the natural protective secretions.
Dobell's solution or alkaline antiseptic solutions were commonly used. Silvol and argyrol solutions were favorites, and chlorinated sprays were used in many places. Solutions of quinine and of zinc sulphate are also mentioned in reports.
Sprays of various kinds were used in the ninth, tenth, and eleventh naval districts and the medical aid to the commandant was of opinion that the procedure distinctly limited the number of cases. The medicament used seemed to be of less importance than the care with which the spraying was done. Reports from numerous stations indicate that cases began to decline in number and severity after spraying was resorted to. Of course, cases usually declined rapidly in numbers and severity as soon as the peak of the epidemic was reached, even though no special preventive measures were undertaken.
If sprays are used it would seem that they should be mildly stimulating but incapable of inflaming the mucous membranes. A spray which causes the mucous membranes to secrete freely may be useful in aiding mechanical elimination of microörganisms which have gained access to the nose or pharynx, but it should be borne in mind that the use of spray apparatus on a number of men in turn is not without danger of becoming a means of disseminating infection.
Another method of applying a medicament to the mucous membranes for prophylactic purposes, and one quite generally overlooked, apparently, was the administration of urotropin to healthy persons during the epidemic. It was observed by a medical officer of the Navy stationed at Los Angeles, Cal., that among 611 persons living in the city, varying in age from 15 to 60 years, who took 6 grains of urotropin three times a day, influenza was contracted in only one instance, the exception being a man of 50 who was irregular in taking his prophylactic doses. The other 610 persons were said to have been exposed to influenza fully as much as their neighbors, many of whom contracted the disease.
Relief of overcrowding.--Overcrowding was undoubtedly an important factor in contributing to the spread of influenza and particularly to the development of complications. However, epidemic
influenza was so highly communicable and so many factors besides overcrowding, per se, entered into the causation and propagation of every outbreak that it was impossible in many instances to determine just what the effect was upon incidence rates or upon case-fatality and epidemic death rates.
The Navy was at its greatest numerical strength during the epidemic period and overcrowding at shore stations was very general. The dangers of overcrowding were recognized everywhere but at many stations gross overcrowding could only be relieved by granting liberty freely and allowing men to sleep outside the station. The size of barracks and the number of men occupying one compartment; ventilation; the size of the station (density of population); nature of activities carried on; the arrival of men from other stations bringing new foci of infection or fresh susceptible material; and the character of the epidemic in the environment all had a bearing on epidemic conditions in the station. For these reasons the rates for the principal naval stations in the United States do not reveal clearly the effects of overcrowding although some were more overcrowded than others. The tendency was for large stations to suffer more than small ones. In some instances where there was great overcrowding the rates were not particularly high and in other instances where it could not be said that an unusual degree of overcrowding existed the incidence of the disease was high. Attack rates among the forces afloat were comparatively low although practically all ships were overcrowded.
Taking everything into consideration, careful study of the conditions existing in the Navy during the epidemics leads to the conviction that overcrowding was one of the most serious conditions with which medical officers had to contend in combating influenza and a most important factor in leading to the development and spread of influenzal pneumonia.
In the fourth naval district it was noted that influenza spread more rapidly in barracks than in tent camps. At Cape May, N.J., 150 cases of influenza occurred and while the attack rate was only 8.7 per cent the case-fatality and epidemic death rates were high, 9.3 and 8.1 per thousand respectively. During this epidemic period (September, 1918) no case occurred at the section base, Cape May, where all men lived in tents. Very few cases occurred at the coastal air stations where about half of the complement was quartered in tents. The more or less isolated positions of these stations and the absence of congestion of population in the environment are to be considered.
At Newport, R.I., in order to make room for the care of the sick, 1,000 men were transferred from the receiving barracks at Cloyne Field and quartered in large pyramidal tents on the Vanderbilt farm, September 15. "Cases of influenza continued to develop in large numbers for three days only, the epidemic among this personnel practically terminating on September 19, despite cold, rainy weather." "Removal to the tent camp in the country appeared to check the epidemic." However, the epidemic at the training station, near Cloyne Field, where many of the men were quartered in barracks similar in type to the receiving barracks, was also practically over on September 19. At the training station a portion of the complement
was quartered in small tents and the men in these suffered equally with those in barracks.
At Block Island, R.I., the personnel at the section base was moved into tents because it was noted that cases of influenza developed only in men subsisted in the civilian community. No case occurred subsequently. At the section base, Woods Hole, Mass., also located in an isolated position, only a few cases of influenza developed among the complement of 188 officers and men during the period of severe epidemics in September and October, but a local outbreak occurred during the week ending November 30, resulting in 22 cases of influenza and 1 death from pneumonia.
In the receiving ship at Boston (Commonwealth Pier), which was grossly overcrowded when the epidemic began, arrangements were made at once to establish a tent camp. From September 20 to November 1, the average complement of the receiving ship was more than 4,000. Of that number, approximately three-fifths were under canvas at Framingham, Mass. During this period, although the primary epidemic had passed, there were 157 cases of influenza, of which 140 occurred in Commonwealth Pier and only 17 in the tent camp at Framingham, in spite of the fact that more men were quartered in the camp.
Ventilation.--The mass of data covering influenza in the Navy during 1918 contains much evidence that the degree of ventilation had an important bearing on the spread of the primary disease as well as on the dissemination of the microörganisms which as secondary invaders appeared to be largely responsible for fatalities. In fact, the enforcement of good ventilation stands out as one of the few preventive measures among those generally applicable which may be expected to have a definite influence in checking the spread of influenza and to make for a low epidemic death rate.
On board ship and at naval stations the operation of many other factors made it quite impossible to study the effect of ventilation by itself and the conclusion reached is rather a conviction formed by reading detailed reports of many epidemics, taking into account all attending circumstances, than one based on incidence and mortality figures. The statistics for an entire station are unsatisfactory in practically all instances for a study of the effect of good or bad ventilation.
The fact that the air was constantly in motion and rapidly removed from a room or compartment often seemed to bear a direct relation to a lower incidence rate and a lower percentage of fatal or complicated cases than in barracks or ships where ventilation was less adequate. Without minimizing the importance of the "droplet spray" as a means of transmission it is reasonable to assume that for a short time nose and throat discharges in finely divided particles may float in the air where they may convey microörganisms to other persons not necessarily in close contact. With good ventilation such material is constantly being removed.
Reports from ships indicated in several instances that the incidence of influenza was lower in well-ventilated compartments than in other compartments. It was noted during an epidemic on board the U.S.S. Orizaba, en route to Europe, that many cases occurred among troops who were quartered in a troop compartment on the
port side where very weak currents of air were issuing from ventilator outlets while practically no cases occurred on the starboard side where the air supply was abundant.
The United States Naval Aviation Detachment, Bolsena, Italy, was housed in barracks under exceptionally good conditions with regard to ventilation. Each man had 1,080 cubic feet of air space and free ventilation was maintained constantly. At a neighboring Italian station there was considerable overcrowding, each man having approximately 270 cubic feet of air space. It was the custom here to keep the windows closed and it appeared that extra precautions were taken during the influenza epidemic to guard against too much fresh air by the use of canvas curtains around bunks and by caulking all cracks with cloth. In the city of Bolsena the same fear of fresh air was noted. "Frequently 8 to 12 persons were found sleeping in dark, low rooms of perhaps 10 by 18 feet, with the one window closed and padded to secure extra protection against fresh air."
The essential epidemiological data were as follows:
|Length of epidemic||6 days||40 days||57 days|
|United States detachment, Oct. 8-13.|
|Italian station, Oct. 1-Nov. 10.|
|City of Bolsena, Sept. 28-Nov. 23.|
|Cases of influenza||13||185||700|
|Percentage of complement attacked||22.41||31.9||18.42|
|Case-fatality rate, per cent||4.86||6.42|
|Epidemic death rate||1.50||1.18|
In Guantanamo City, Cuba, during the epidemic, as observed by medical officers of the Navy, the incidence of influenza was very high and the disease was very fatal, especially in the cases of Haitians and Cubans, among whom sanitary conditions were bad and the practice of tightly closing all doors and windows was followed. In Caimanera and Boqueron, on the other hand, where sanitation was supervised and good ventilation insisted upon the mortality was extremely low.
Influenza was introduced into Guam October 26, 1918, from Manila, P.I., and spread rapidly. Only a few individual escaped attack, so that the case-fatality rate was practically the epidemic death rate. Approximately 4.5 per cent of the native population died.
|Under 5 years||22.55|
|5 to 10 years||4.98|
|10 to 20 years||3.10|
|20 to 30 years||4.55|
|30 to 40 years||6.72|
|40 to 50 years||9.76|
|50 to 60 years||14.72|
|60 to 70 years||16.70|
|Over 70 years||16.92|
"Apparently the causative agent was spread by the air, which may probably be explained by the high degree of relative humidity prevailing on this climate." "Large numbers of persons were attacked simultaneously by the disease, although so far as known they had not been in close contact with the sick." "Native houses are built entirely too close together, and entirely too many people live in the same house." "The people crowd into these houses and sleep on mats spread on the floor with windows and doors tightly closed." the majority of cases among Americans were very mild and only one resulted fatally, a case of broncho-pneumonia in a carpenter's mate, second class. All medical officers and all but three nurses contracted influenza.
In the Philippines the disease early assumed grave proportions among the native population, spread rapidly, and caused many deaths. It even spread to the leper colony at Culion, where the death rate was very high. The same fulminating types seen in other parts of the world were noted and in the early part of the epidemic the diagnosis of pneumonic plague was seriously considered in one case. Taken altogether the enlisted personnel of the Navy and Marine Corps, including native forces, really suffered from influenza very slightly. The incidence among nurses and hospital corpsmen was low.
Among natives in Olangapo the attack rate was between 30 and 35 per cent; the epidemic death rate, approximately 8 per thousand, and the case-fatality rate, about 2.5 per cent. "The mortality among the very young and the very old and those affected with tuberculosis, of which there were many, was very high." Overcrowding in stuffy shacks is the prevailing custom among the natives. Doors and windows are closed tightly at night, but as a rule there are upward drafts through the bamboo floors. During the greater part of the epidemic period the weather was windy and inclement.
In brief, Navy reports from Guam, the Philippines, China, Japan, Cuba, Haiti, Santo Domingo, and Nicaragua indicate that influenza among Americans and European was a milder disease than among natives, and that relatively fewer were attacked.
While one may readily believe that insistence upon good ventilation with as many changes of air per hour as can be secured without causing real discomfort is an important preventive measure, the instances cited show how unsatisfactory attempts are to prove this directly from data accumulated during the epidemics. In almost every instance, bad ventilation was intimately associated with overcrowding and other insanitary practices. Density of population and individual susceptibility are to be considered also.
Use of screens in barracks between bunks or hammocks.--This measure was very generally adopted. Like other measures based on the assumption that modes of transmission in the case of influenza are those of communicable diseases of the respiratory type the use of screens would appear to be an important preventive measure, especially with a view to limiting the dissemination of pneumococci, streptococci, and other known microÖrganisms. The means of transference other than under sleeping conditions were infinite and epidemic influenza proved to be so highly communicable that it is not to be expected that direct evidence of the efficacy of screens would be forthcoming.
Disinfection of articles liable to contamination with nose and throat discharges.--It is the ordinary practice in the Navy to sterilize all mess gear and the dangers of the "common drinking cup" are universally recognized. Extra precautions were taken everywhere throughout the epidemic period to prevent possible infection from such sources. In all probability chances for infection in this way occurred in isolated instances but there is no direct evidence to show that such articles were the means of disseminating influenza in the Navy. It is obviously impossible to judge the part played by towels, handkerchiefs, pipes, Bull Durham bags, and numerous other articles subject to transfer from one person to another.
Restriction of gatherings indoors.--At most stations steps were taken to keep the men out of doors. In many instances, Y.M.C.A. buildings were closed and indoor recreation was suspended. The effect of such measures is still problematical. It is to be borne in mind, however, that by closing centers of entertainment and recreation it is frequently possible to do more harm than good in congested stations. In a large naval station where overcrowding exists, and especially where the environment is a large and congested city, it is perhaps better to keep such centers open, paying due attention to ventilation. At a small station in a more isolated position it may be advisable to prevent gatherings indoors.
Daily inspection of the entire personnel.--This measure is always indicated in the Navy when an outbreak of any communicable disease of the respiratory type threatens. The procedure was not always practicable during epidemics of influenza, particularly at the larger stations. At the United States Naval Training Station, Hampton Roads, Va., "morning temperatures" were taken of as many of the personnel as possible. Those having a rise of temperature, even through they felt perfectly well, were placed on the sick list and isolated, for experience had shown that the majority usually developed symptoms of influenza later in the day.
In the receiving ship at Norfolk (St. Helena Station) a daily morning and afternoon inspection of the entire personnel was instituted. Men showing various degrees of temperature elevation were segregated for observation. About 60 per cent of these developed typical symptoms of influenza, but upon questioning them it was learned that practically all had suffered with "colds" or headache prior to having been picked from ranks, although they had not considered themselves sick enough to go to the sick bay. Among those showing a rise in temperature not followed by the development of influenza the elevation was attributed to various causes: No disease, 14 per cent; acute rhinitis, 11 per cent; autointoxication, 6 per cent; constipation, 5 per cent; acute otitis media, 1 per cent; acute tonsillitis, 1 per cent; acute pulmonary tuberculosis, 1 per cent; diagnosis undetermined, 1 per cent.
Early isolation of the sick.--This was universally recognized as an important preventive measure, as it is in the case of any communicable disease, for the protection of those who might otherwise be exposed. It is particularly important to put the influenza patient to bed as soon as possible for his own welfare.
In some instances the question arose as to whether it was the best policy to isolate patients in dispensaries and barrack buildings set
apart for the purpose or to transfer all patients to hospital. In many instances there was no choice in the matter. All accommodations for the care of the sick were required so that the more serious cases were transferred to hospital, those moderately ill were kept in dispensaries, and mild cases were treated in barracks.
No matter what the circumstances under which patients were treated, experience would indicate that the use of screens between beds, with a view to preventing cross infections, was a most important measure. The greater the number of patients the more danger of cross infection. Uncomplicated cases of influenza should not be treated in the same ward with cases of influenzal pneumonia, and the latter should be adequately screened ipso jure with the hope of preventing cross infection among themselves. It was not always possible wholly to separate uncomplicated cases from cases of influenzal pneumonia. It was always possible to institute an aseptic technique and modified cubicle system, improvised by means of screens.
On theoretical grounds it would seem to be the better policy, where reasonably good care can be given, not to send influenza patients to a central hospital during an epidemic if it can be avoided, the risks of complications being less when patients are treated alone or in small separated groups. It would also appear that if patients must be transferred to hospital they should be transferred early in the disease. After pulmonary complications have set in, removal is often hazardous and, as in the case of measles, exposure of the influenzal pneumonia patient to the cold or fatigue incident to a long ambulance ride is liable to be exceedingly dangerous. In civil communities it is very questionable if influenza patients, even those in poor circumstances, should be transferred to hospital if good ventilation can be secured in the home, if proper nourishment can be had, if there is an intelligent person to wait upon the patient, and particularly if the services of a district or visiting nurse are available. Ordinary medical skill often seemed to avail more under such circumstances than the services of highly trained internists under the best hospital conditions obtainable during the epidemic. In the Navy, service conditions sometimes make it expedient to transfer a patient to the base hospital when a case similar in character would not be removed in a civil community.
It was the consensus of opinion among many observers that the patient is fortunate who can go to bed at once and remain there until free of fever and until his strength begins to return.
It was observed in the receiving ship at Norfolk (St. Helena Station) that the period of early convalescence appeared to be a time of great danger to the patient, for he was then extremely susceptible to pneumonia. Feeling more comfortable, though weak, he was apt to become restless and expose himself rashly, possibly getting out of bed and walking to the toilet with bare feet. Under such circumstances definite symptoms of pneumonia not infrequently developed within a few hours. Several patients developed broncho-pneumonia after two days of normal temperature where there had been non exposure and where the nursing was careful and competent. However, it was the conviction of medical officers at this station that "early to bed, avoidance of chilling, and fresh air treatment" will many times prevent complications.
At the marine barracks, Quantico, Va., it was the practice to discharge all influenza patients into a convalescent camp, separating patients who were coughing from the others. Approximately 10 per cent of convalescent patients subsequently had fever after four days of normal temperature. In the isolation hospital at that station all influenza patients who developed pneumonia were at once removed to a separate ward.
At the United States Naval Air Station, Pauillac, France, there were few complications during the epidemic, and it was reported that there were fewer deaths than among other organizations on the coast. No special preventive measures could be instituted among the personnel at large because of imperative industrial demands of war. The low mortality was attributed to putting every patient to bed as soon as he complained of feeling badly, thorough spraying, and absolutely no moving or transferring.
Experience at the United States Naval Training Station, Great Lakes, Ill., led medical officers to believe that transfer of patients to hospital tended to increase the number of cases in which pneumonic complications developed. A similar belief was held by the medical officer of the officer material school, Pelham Bay Park, New York, who reported that mild cases of influenza were not transferred to hospital because of a belief that fewer complications would result if not transferred. He remarked that repeated exposure of patients with cough certainly predisposed to the development of pneumonia.
At the United States Naval Hospital, Philadelphia, Pa., Pa., among 362 cases admitted to hospital during the epidemic within 24 hours of the onset of influenza, the case-fatality rate was 2.8 per cent; among 197 admitted within 48 hours, 8.6 per cent; among 116 admitted between 48 and 72 hours after onset, 30.2 per cent, and among 235 cases admitted after 72 hours, 30 per cent.
At the United States Naval Hospital, Great Lakes, Ill., the case-fatality rate among 2,924 cases of influenza transferred to hospital was 30.5 per cent. Of these cases 1,807 had pneumonia, making a case fatality rate of 46.2 per cent for influenzal pneumonia. For the 2,924 cases of influenza the average duration of illness before admission to hospital was 5 days.
At all naval stations confronted with fulminating outbreaks of influenza, the cases which developed complications and those which in the judgment of medical officers promised to be serious from the beginning, were the ones principally transferred to hospital. Such selection of cases was usually necessary for the conservation of both hospital and dispensary beds.
Fatigue.--The determining factor in the development of influenza appears to be lack of specific immunity and certainly a high percentage of all persons seem to be susceptible at one time or another when the disease is prevalent. Nevertheless, the element of fatigue seems in many cases to have played a part in the development of complications.
Experience at the United States Naval Training Station, Newport, R.I., indicated that fatigue was responsible for a certain number of the cases of influenza and the schedule of instruction for incoming recruits was rearranged so as to be less fatiguing than under the former system. This change seemed to be beneficial.
Observations made by a medical officer of the Navy at the large post at Gievres, France, which was divided into subposts A, Engineer; B, Medical; C, Ordnance; D. Quartermaster; E, West End; F, Quartermaster, seemed to indicate a close relationship between the incidence of influenza, particularly the severe cases, and physical fatigue, long hours of uninterrupted labor with no relaxation from routine duties, no entertainment or change of scenery, and exposure to cold, inclement weather. The quartermaster and labor organizations suffered much more heavily than other organizations.
That there is evidence to the contrary in respect to fatigue and exposure, as there is in relation to all other epidemiological factors, is shown by experience on board the U.S.S. Lebanon during the epidemic period. It was regarded as remarkable that no case occurred on board, in spite of the fact that no precautions could be taken to prevent the introduction of influenza other than to keep berthing spaces well aired, to sun bedding, and require men to shift into dry clothing after the day's work was done. The crew was exposed to all kinds of weather. Men were frequently wet from the waist down, and they worked long hours both day and night in the preparation of target rafts for gunnery practice.
Travel.--Influenza is spread by travel. Attempts were made in the Navy to reduce travel between stations to a minimum consistent with the requirements of war. The history of the disease in the United States during the autumn of 1918 shows that it was carried speedily to all parts of the country by travel among civilians. In spite of all efforts to limit the transfer of men, influenza was spread by a draft of men from Boston to the navy yard, Philadelphia, Pa., and from there directly to the navy yard, Puget Sound, Wash., by another draft. Unquestionably the disease would have reached these stations in the course of a short time via the civilian communities. Nevertheless, it would seem advisable to stop travel between naval stations and between stations and ships during the course of an influenza epidemic or when an epidemic threatens, in the attempt to prevent by all possible means the introduction and spread of the disease from one ship or station to another on the principle that the longer the development of an epidemic can be delayed the less likely is the epidemic death rate to be high.
The conditions under which drafts are moved by rail, more especially for long distances, almost always involve such predisposing influences as overcrowding, bad ventilation, interrupted sleep, and irregular meals, and frequently poorly-heated cars in cold weather.
Educational measures.--The importance of educational measures was fully appreciated by medical officers who disseminated information on influenza among the personnel generally by means of talks, bulletins, and posters.
The bureau issued a warning in the weekly bulletin, Notes on Preventive Medicine for Medical Officers, United States Navy, of August 9, 1918, that influenza had again assumed pandemic proportions and thereafter sought to inform medical officers promptly of developments and to supply them with information of an educational value week by week, as fast as knowledge was acquired during the course of the epidemics, which proved to be of unprecedented severity.
The following are samples of circulars and posters published at various naval stations:
MARINE BARRACKS, QUANTICO, VA.
PROTECT YOURSELF FROM SPANISH INFLUENZA, DIPHTHERIA, SCARLET FEVER, SORE THROAT, MUMPS, BAD COLDS, GRIPPE, TONSILLITIS, MENINGITIS, TUBERCULOSIS, MEASLES, WHOOPING COUGH, PNEUMONIA.
The above diseases are transmitted through the secretions of the mouth and nose of sick people or "carriers." "Carriers" are persons who do not show symptoms of the disease, yet harbor the germs.
Measures taken to avoid the germs or "bugs" causing the diseases.
Common drinking cups.
Stay away from one who is coughing or sneezing as minute infectious materials are expelled into the air by this process. When you cough or sneeze, do so into a handkerchief, or else bend your head downwards.
Do not put into your moth, fingers, pencils, or anything else that does not belong there.
Free ventilation; keep windows open as much as consistent with the climate. This causes dilution of the impure air and renders it less infectious.
Measures taken to avoid lowered resistance to disease.
Excessive fatigue, worry, or mental exhaustion.
Unnecessary exposure to cold or wet.
Change wet clothing whenever necessary, especially shoes and socks.
(b) Promote health by
Frequent baths followed by a brisk rub down.
Mild physical exercises.
Drink one or two glasses of water on rising.
Keep well covered with blankets at night.
Brush teeth regularly.
Wash your hands before each meal.
Lieutenant-Commander, Medical Corps, U.S.N., Post Surgeon.
UNITED STATES NAVY YARD,
Mare Island, Cal., September 25, 1918.
1. Influenza, Spanish influenza, or grippe, has made its appearance in the Eastern and Middle Western States in the form of a rapidly spreading epidemic. Since it will undoubtedly be carried here the following information is given in order that you may be in a better position to prevent its spared, thereby protecting the members of your household and your neighbors.
2. No other communicable disease which assumes epidemic proportions spreads so rapidly or attacks so large a proportion of the population, no age, sex, or class of society being immune.
3. The infectious agent is the influenza germ which is carried by the secretions of the nose and mouth.
4. The modes of infection are (1) directly from the infected individual by coughing, spitting, sneezing, or by in any way coming in contact with the nasal
or mouth secretions; (2) by indirect methods through contact with articles soiled by the above-mentioned secretions, such as handkerchiefs, towels, mess-gear, etc. In this connection it must be remembered that the disease germs often persist in the nose and throat for some time after the symptoms of the illness have subsided.
5. The incubation period is very short, one to four days, average two.
6. Methods of control.--(1) Early recognition of the case: In order that cases may be early recognized a brief description of the onset and symptoms is given. Onset usually rapid, with a chill followed by fever from 102° to 104°, great depression, weakness, dizziness, severe headache, backache, pains, and soreness of muscles and joints all over the body. The throat may feel sore, the eyes are congested and do not bear the light well. There are practically always symptoms of a bad cold, with running eyes and nose, soreness and tightness of chest with coughing. Anyone presenting the foregoing symptoms, or any one of them should report at once to a medical officer. (2) When the case has been recognized, rigid isolation must be carried out; only one attendant for each case; attendant must wear gown and gauze face mask.
7. Concurrent disinfection must be practiced to include all articles which have come in contact with the patient such as clothing, bedding, messgear, books, papers, letters and all personal belongings of attendant. Careful nursing in a warm, well ventilated room is an essential part of the treatment. Pneumonia is a common complication.
8. Terminal disinfection, thorough cleansing and airing of the compartment occupied and sterilization of all linen and bedding of patient.
9. Vaccination against influenza is partially successful.
10. General methods to prevent the spread of infection.
- Avoid crowded assemblages during the epidemic such as theaters, picture shows, public gatherings of all kinds.
- Avoid traveling on congested public conveyances.
- Do no cough, spit, or sneeze promiscuously; always use your handkerchief over your mouth when coughing or sneezing.
JOHN L. NIELSON,
Commander, Medical Corps, United States Navy.
Captain, United States Navy, Retired, Commandant.
Mare Island, Cal., September 24, 1918.
Commanding officers shall comply as far as practicable with the following
- No recruits or drafts to be sent to this station until the probability of an epidemic no longer exists.
- Sleeping space per man to be 50 square feet; overflow to be placed in tents.
- Cubical isolation to be established by hanging curtains between bunks or cots and between hammocks. Sheets and other available material may be used for this purpose.
- A copy of this notice to be conspicuously posted, and all enlisted men and civil employees to be made acquainted with the contents thereof.
It is impossible to establish a strict quarantine at this yard without closing
the yard, and no efficient separation between civilians and military personnel
can be established. A modified quarantine as follows is hereby directed:
- Continue 21-day detention of all arrivals as at present.
- When cases develop in adjacent towns stop liberty; stop congested gatherings of personnel, such as theaters, moving pictures, recreation rooms, reading rooms, churches, class rooms, etc. Permit only drills, amusements, and instruction in the open air.
- Strict isolation of cases of the disease with concurrent and terminal disinfection. Attendants on cases to wear gowns and face masks, and to observe strictly the disinfection of the hands after handling cases. Cubicle isolation of patients, as above provided, to be complied with.
- All spoons, knives, forks and cups, and other articles of mess gear to be boiled in dishwashing machines for a period of five minutes. Competent persons are to be detailed to see that this provision is carried out.
- Fatigue of personnel to be reduced by limiting drills and other military exercises. Clothing protection to be ample, and latitude to be permitted consistent with the maintenance of discipline. All washable clothing to be steam laundered, especially handkerchiefs and towels.
- The swimming pool is to be given a little chlorine in excess of that used at present, and is to be closed entirely if influenza appears on the station.
- All sanitary drinking terminals with globe tips to have the porcelain globular portion of the terminal removed.
- Additional personnel to cope with an anticipated epidemic has been requested by the commandant. Provision for temporary hospital facilities for sick, within the limits of the naval training camp and marine barracks, to be accomplished either by hospital tents or the assignment of certain barrack buildings for that purpose. Severe cases, or those developing into pneumonia, to be sent to the naval hospital; mild cases may be cared for in temporary hospitals established in the camps.
- Provisions for the care of civilian sick to be established at the island, such civilian cases to be limited to those individuals who have no home where they can be nursed and fed while sick. The naval hospital has arranged to care for severe cases and pneumonia among civil employees, and, if necessary, mild cases may be treated in temporary hospitals at camps or temporary hospital near yard dispensary.
Captain, U.S. Navy (Retired), Commandant.
U.S.S. "MISSISSIPPI," September 15, 1918.
|Subject:||(a)Sanitary Bulletin No. 6.|
1. Influenza or "grippe" is more contagious than measles. Though it is common enough at all times, there have been several epidemics. In 1889-90 there was a world-wide epidemic in which three-fourths of our city populations were affected. It is caused by a germ--the bacillus of influenza. The infection is introduced through the nose and throat. It spreads most rapidly where people are crowded, as on a ship, because the air becomes filled with germs from the coughing and sneezing of those who have the disease. It is like a "common cold," but is of greater severity.
2. Symptoms.--It may begin within a few hours after infection, or may not appear for several days. It begins suddenly with fever, headache, pains in back and shoulders, and feeling of weakness. Coughing and sneezing appear early in the attack. The cough is at first dry and hacking, and may be accompanied by the sensation of suffocation. There are many complications which occur. Pneumonia appears to be common in this epidemic. After recovery a feeling of depression is liable to last a long time.
3. Prevention.--It is a dangerous disease and will, if we should have many cases, make it difficult to "play the game." We have not a single case aboard. Help us to keep clear of it.
When coughing or sneezing place a handkerchief in front of your face.
Swing your hammock head to foot.
Keep out of crowds.
Don't use any else's towel, handkerchief, or cup.
Get lots of fresh air.
Report at sick call if you have a "cold."
Avoid the lip,
Escape the bug
That gives the "grippe."
Approved for publication.
(Signed) B.F. HUTCHISON,
Captain, United States Navy, Commanding.
U.S.S. "MISSISSIPPI," October 8, 1918.
|Subject:||(a)Sanitary Bulletin No. 7.|
|(b) Present status of influenza.|
1. Influenza is with us, but it is mild. We have had very few cases, and the majority of these have not been severe. We have fared better than the other ships in the fleet. A number of deaths have been reported from other ships. We have not had a single death. Only three of our patients have been sick enough to necessitate transferring them to the hospital ship, and these are now on the road to recovery. We now have 15 cases, and 8 have been returned to duty. These fine results are not a matter of luck; they are due to the splendid cooperation of the officers and men of the Mississippi. Keep up the good work.
2. When coughing or sneezing place a handkerchief in front of your face.
3. Swing your hammock head to foot.
4. Keep out of crowds.
5. Don't use anyone else's towel, handkerchief, or cup.
6. Get lots of fresh air.
7. Report at sick call if you have a "cold."
8. A clean ship is a healthy ship. Clean 'em up, Mississippi.
(Signed) B.F. HUTCHINSON,
Captain, United States Navy, Commanding.
The Bureau of Medicine and Surgery published the following circular for use in the Navy Department during the epidemic in Washington, D.C., and copies were distributed also at various naval stations:
DIVISION OF SANITATION,
Washington, D.C., September 26, 1918.
Influenza is "grippe." It is now spreading over the country in epidemic form. The last extensive epidemic occurred in 1889-90, and the disease was very prevalent for several years after.
The present epidemic disease is plain influenza. The term "Spanish influenza" has been applied because of its recent prevalence in Spain. Influenza occurs every year in the United States, but it is more contagious during an epidemic, and pneumonia is a more frequent complication.
Influenza is caused by a germ, the influenza bacillus, which lives but a short time outside of the body. Fresh air and sunshine kill the germ in a few minutes.
The disease is spread by the moist secretions from the noses and throats of infected persons.
Protect yourself from infection, keep well, and do not get hysterical over the epidemic.
Avoid being sprayed by the nose and throat secretions of others.
Beware of those who are coughing and sneezing.
Avoid crowded street cars--walk to the office if possible.
Keep out of crowds--avoid theaters, moving-picture shows, and other place of public assembly.
Do not travel by railroad unless absolutely necessary.
Do not drink from glasses or cups which have been used by others unless you are sure they have been thoroughly cleansed.
You can do much to lessen the danger to yourself by keeping in good physical condition.
Avoid close, stuffy, and poorly ventilated rooms--insist upon fresh air, but avoid disagreeable drafts.
Eat simple, nourishing food and drink plenty of water. Avoid constipation.
Secure at least seven hours sleep. Avoid physical fatigue.
Do not sleep or sit around in damp clothing.
Keep the feet dry.
Influenza usually has a sudden onset with chilliness, severe headache, and "aching all over." At times the disease begins with nausea, vomiting, and abdominal pain. Fever begins early. Frequently catarrhal symptoms do not appear until later. When they do they are the symptoms of a bad cold in the
head with a raw throat and dry cough. Weakness and prostration out of proportion to the fever are common. Former epidemics have been characterized by marked mental depression. In the present epidemic many of the cases are having a gradual onset--more like a gradually increasing cold in the head.
Practically, the great danger from influenza is pneumonia, which tends to follow in a considerable percentage of the cases.
For the protection of others, if your are really sick stay at home and remain there until the fever is over. A day in bed at the very beginning may also save you from serious consequences later on.
If you are up and about, protect healthy persons from infection--don't spray others with the secretions from your nose and throat in coughing, sneezing, laughing, or talking. Cover the mouth with a handkerchief. Boil your handkerchiefs and other contaminated particles. Wash your hands frequently. Keep away from others as much as possible while you have a cough.
If you become ill don't try to keep up with your work. Fight the disease rationally and do not become unduly alarmed. In the average case recovery from acute symptoms follows in five or six days. To hasten recovery and lessen the danger of complications, go to bed at once and keep the body warm. There should be plenty of fresh air, but chilling is to be avoided. At the beginning of the disease a cathartic, such as 21/2 or 3 grains of calomel, followed by a seidlitz powder or epsom salts, is useful. Aspirin in 5-grain doses is useful for pain, but do not take large doses of aspirin, phenacetin, or other medicines. Send for the doctor.
Therapeutic use of the serum of convalescent influenzal-pneumonia patients.--At the United States Naval Hospital, Chelsea, Mass., the treatment of influenzal pneumonia with serum obtained from patients convalescing from influenzal pneumonia was begun early in October. In all, 151 patients were treated, of whom 6 died, making a case-fatality rate of 4 per cent. Most of these cases were treated early in the course of the pneumonic complication. The average dose of serum was 120 cc. Lieutenant Commander L.W. McGuire and Lieutenant W.R. Redden, Medical Corps, United States Navy, who conducted this work concluded that "pooled serum from convalescent influenzal broncho-pneumonia patients at this hospital has greatly reduced mortality, has shortened the course of the disease, and has proved almost a specific, not only during a waning epidemic but also during the more recent severe recrudescence." The recrudescence referred to included cases from the U.S.S. Yacona previously mentioned in connection with experimental attempts at the Boston station to transmit influenza to volunteers. The best results were secured in cases showing leucopenia. The outcome of streptococcus pneumonia cases was not influenced much by the serum treatment and therefore serum was not administered in cases diagnosed as streptococcus pneumonia by lung puncture. Apart from this, the cases treated with serum showed striking and immediate improvement clinically in most instances.
At the United States Naval Hospital, Washington, D.C., Lieutenant F.W. Hartman, Medical Corps, United States Navy, reports that of 567 cases of influenza, 157, or 27 per cent, developed pneumonia. One hundred and eleven were not treated with serum. Of these, 28 died, making a case-fatality rate of 25.2 per cent. Forty-six cases were treated with serum from patients convalescing from influenzal pneumonia, with the result that there were only 3 deaths or a case fatality rate of 6.5 per cent. Pneumococcus empyema was found in two of the fatal cases, and streptococci were recovered by lung puncture in the third.
At the United States Naval Hospital, Parris Island, S.C., 48 cases of influenza pneumonia were treated with serum from patients convalescing
from influenzal pneumonia with 35 recoveries and 13 deaths, making a case fatality rate of 27 per cent. During the early part of the epidemic it was impossible to follow the blood counts closely but with two or three exceptions the usual leucopenia was noted. Leucopenia gradually disappeared with improvement in the patient's condition. The serum did not cause a sudden increase in the leucocyte count. Serum from convalescent influenza patients was apparently of little value. There was considerable variation in the potency of serum donated by different patients convalescing from pneumonia. One donor yielded 500 c.c. of serum and invariably the recipients of his serum showed marked improvement even after that from other donors had failed to relieve symptoms. Lieutenant Commander J.A. Bass and Lieutenant C.E. Ervin, Medical Corps, United States Navy, who reported these cases concluded, "In spite of the high mortality rate, as noted above, we are satisfied beyond the shadow of a doubt that the use of serum from convalescent influenzal pneumonia patients is of marked value in the treatment of influenzal pneumonia." "The sooner the treatment is begun the better the prognosis." "Treatment was not withheld in any instance because the patient seemed hopelessly ill when first seen."
At the United States Naval Hospital, Great Lakes, Ill., it was concluded that the use of serum from convalescent patients was of practically no account. During the early part of the epidemic patients received were desperately sick and conclusions were held up with regard to this treatment. Later, when fresher cases were received the good results that others reported were not obtained.
On board the U.S.S. Solace (hospital ship) the supply of human serum was limited and was only administered to those patients who were critically ill. Of nine cases treated, two died. One of these was admitted in a moribund condition. In the other fatal case the findings were double pneumonia, pneumococcus septicemia and pneumococcus (Type III) meningitis. From one to eight doses of serum were administered in the remaining seven cases. In three instances improvement was rapid; in the others more gradual, but the medical officers in charge of the cases had no doubt that the serum produced beneficial results.
If pneumonia in its various forms could have been eliminated as a cause of death, the death rate of the Navy for disease only would be 1.8 per 1,000 instead of 11.78.
Deaths from pneumonia complicating measles are charged to measles as the primary cause of death. Deaths from pneumonia
complicating influenza are charged to influenza as the primary cause of death.
Epidemic influenza with its fatal pulmonary complications so overshadowed all other causes of death that it has been taken up in detail under a separate heading. Chart No. 5 shows the effect of influenza on the admission rate for pneumonia during September, October, and November.
With regard to primary lobar pneumonia, this disease has its greatest prevalence during the months of January, February, March, and April, when exposure to raw, cold, wet, and windy weather is common. (See chart No. 5.) This together with fatigue and other predisposing influences are of great importance in determining development of the disease. During the autumn of 1918 lobar pneumonia was unduly prevalent.
During the first six months of the calendar year 1918, there were 422 deaths from primary lobar pneumonia, with a semiannual death rate of 102 per 100,000. During the first six months of 1919 there were only 82 deaths from primary lobar pneumonia, making a semiannual death rate of 18.3 per 100,000. In this period the bulk of the pneumonias reported were of the influenzal type following in the wake of the great pandemic. It is not unlikely that many of the pneumonias which occurred during the spring of 1918 were in reality largely influenzal in origin, although not recognized as such and therefore considered to be frank lobar pneumonia. Certain it is that streptococci were active invaders, producing a mixed infection of high virulence, as instanced by the large number of deaths from measles pneumonia.
The death rate for pneumonia (lobar and primary bronchial) for the force ashore was 281 per 100,000 while the rate for the same causes for the force afloat was only 78 per 100,000. The admission rates were 55.28 per 1,000 and 8.87 per 1,000, respectively.
There were in all 757 deaths from lobar and primary broncho-pneumonia in the entire Navy during the calendar year 1918. There is thus a death rate of 15.02. (See chart No. 18.) The death rate for civil communities for the year 1917 (figures of 1918 not available) was 149.8 per 100,000.
The following table gives the results of typing in cases of lobar pneumonia:
|Type I.||Type II.||Type III.||Type IV.||Total.|
|Pelham Bay Park||3||------||------||------||3|
Chart No. 18.--Annual death rates per 100,000 for certain communicable diseases, entire Navy, calendar years 1909 to 1918.
Source: Annual Report of the Secretary of the Navy, 1919 -- Miscellaneous Reports. (Washington: Government Printing Office, 1919). pp 2414-2506.