Part 2

In a recent article published by Loy McAfee (J. A. M. A., 1917, 72, 445) he discussed the confusion which existed between the diagnosis of cerebro-spinal meningitis and epidemic influenza in 1863. These were believed the same by some—that is, the same disease of varying degree. There was a great diversity of opinion among clinicians at this time, and the American Medical Association appointed a committee to make an investigation. McAfee quotes from the Medical and Surgical History of the War of the Rebellion that in 1861 and 1862 an epidemic existed among the troops called epidemic catarrh, which was afterward changed to read acute bronchitis. In September, 1861, there existed an epidemic of influenza in one of the regiments which lasted more than two weeks, and in another camp there was a similar epidemic at the same time. It is stated that there were in all 168,715 cases among the white troops, with a mortality of 650, and 22,648 among the negro troops, with a mortality of 255, making about 4 per thousand, and over 11 per thousand, respectively.

The next great epidemic, and the last until the present, occurred in the years 1889 and 1892, and was pandemic in its nature. The death rate during this time was lower in the cities than in the country. This was probably due to the fact that the greatest mortality was among children and old people, and as old people were generally left in the country, this explains the observation. The highest number of deaths was among males, believed to be due to the exposure and fatigue of work. Forty per cent. of the world’s population was said to have been attacked during this period. The yearly or seasonal repetition, as shown in this pandemic, had occurred in other epidemics. In the great pandemic of 1889 and 1890, five decades after the last important epidemic, it was stated that the medical profession found itself confronted by a new disease of which it had knowledge through medical history, so also in our time few physicians recognized at first the reappearance of influenza. This 1889 epidemic is extensively reported in the literature, and has been elaborately worked out by many observers. One important feature has been emphasized by Leichtenstern, which, although recognized by the profession after the last epidemic had been fully reported and recorded, is not appreciated by the profession during the present epidemic—namely, that while shortly after the last epidemic there were smaller relightings of the infection throughout various parts of the country, those diseases which we erroneously call grippe or influenza, occurring commonly in the spring and fall, are in no way connected with the disease with which we are dealing, and which occurs at rather long intervals. Any speculation in regard to these periods, which history has shown to be fairly wide apart, has very little basis. This pandemic, like many of former days, is believed to have originated in Asia, and from there to have spread over Europe and hence over the world. The disease spread rapidly over countries, affected probably about 40 per cent. of the world’s population, disappeared rapidly after several weeks, was thought to have had nothing to do with weather conditions, had a great morbidity but small mortality, and affected all ages and occupations. There is no doubt, as stated by some, that the development of traffic and travel was a large factor in the rapid and extensive spread of influenza during this pandemic. The course which the disease followed, springing from its supposed beginning in Asia, has been fully and amply described by writers after that period, but the great rapidity of its dissemination over all countries is the most remarkable feature in the epidemiology of any disease. This, during 1889, made many prominent physicians disregard the opinion that influenza spread by contagion and accept again the opinion expressed by observers of epidemics in former ages, that miasma as a pathogenic agent was responsible for its distribution; but anyone who reads closely the history of this epidemic, and in the light of modern medical science, must feel that the rapidity of distribution was nowhere greater than the most speedy means of transportation. This very necessary close connection was demonstrated also in regard to the mode of spread of the disease; the large cities and the commercial centers were affected earlier, smaller and country districts followed later, railroad towns were more frequently attacked than isolated villages, and even from jails, prisons and workhouses, where quarantine was immediately attempted, as well as from remote villages where the disease had been brought, there could be traced a zone of infection spreading into the country. One interesting point was raised at this time—namely, that in some places it seemed to spread by leaps and bounds, and at other places radiating as stated above.

The old controversy of whether influenza is distributed in a radiating manner or in so-called leaps and bounds is believed to be settled by consensus of opinion that it occurs in both ways. An opinion expressed by the study at this time as to whether influenza spreads more rapidly than any other infectious disease is found in the statement that the contagion is markedly virulent, the micro-organisms are easily conveyed from their original seat in the mucous membrane by coughing, sneezing and expectoration, the great number of persons who, though slightly affected, carried on their ordinary way of life without hindrance, the probable longevity of the organisms in convalescents, the brief period of incubation of two or three days, the susceptibility of all people of every age and vocation, and the possibility of carrying the contagion by merchandise and even through short distances in the air, are all suggestive reasons for this. No one at present accepts the so-called miasmatic nature of the contagion. Proofs are ample to show that one case must be present in a locality or even family, although it may be frequently overlooked, from which the epidemic spreads. During this period of 1889 and 1890 the duration of the actual epidemic period in different localities in Europe was from four to six weeks. This was subsequently shown to be consistent with the recorded reports from the various cities in the United States. Following this pandemic in the first part of the year in 1891 there were numerous epidemic outbreaks in various parts of America, including New Orleans, Chicago, Boston, and simultaneously in England. Strange to say, at this time neither Germany nor France had such epidemics, although both were exposed by travelers, particularly from England and America. The question was raised at that time whether the Germans, French or other continental nations were more immune than Americans and English. In the fall of 1891 and the entire winter of 1892 the disease was extensively prevalent both in Europe and Northern America. In these later epidemics there was no definite direction of spread. They probably would come more clearly under the so-called radiation from numerous rural districts. In almost every case at the point of its origin in these countries the epidemic developed and spread slowly, lasting months and with very varying morbidity and mortality. They had none of the explosive characteristics of the pandemic. The general diminished morbidity of the later epidemic, the diminished geographic distribution of the disease and the scarcely recognizable character of its contagion, its slow development and extension over several months, the continuous diminution in frequency and in intensity since its onset in 1889, have been explained by presumptive successive lessening of susceptibility of the population, possibly due to acquired immunization. Observers at that time, as well as ourselves, could question this last statement.

There was observed one noteworthy thing about seasons. While the great pandemic of 1889 and 1890 had no definite connection with seasons, the epidemic types which followed in 1891 and 1892 seemed to show a lighting up in either spring or fall, remaining dormant in the summer months. It has also been shown by the history of former epidemics that almost all the pandemics started from Russia in the fall, winter and spring months. Such was the case in 10 of the great pandemics of 1729 to 1889. This, no doubt, was the reason so many of the former historical writers were impressed by seasons and meteorological conditions. The statement made by observers during the epidemic that influenza presented two phases, one pandemic and the other endemic, and that each follows different epidemiological rules, seems possible. The question raised during the last epidemic of the spread of the disease in families, the disease occurring at high altitudes and even at sea, we know does not interfere with the recognition of its spread by direct contagion. Definite examples of families or villages being infected by a returned member of such family or citizen from abroad are reported frequently, and even the appearance of the disease in isolated places has often been traced and verified from a definite source, to say nothing of the question of carriers and those supposed to be suffering from other diseases.

Striking examples are shown also in this epidemic that many institutions, frequently those isolated from the world, were markedly exempt until, through servants or outside visitors, the disease gained access to them. This gave a most favorable field for the study of invasion, spread and decline of the disease. Observations made at this time in regard to hospitals seemed to suggest that certain institutions were more or less exempt, although not closed institutions, while others suffered from the first. These two types of hospital invasion are hard to reconcile.

Great stress was laid in this epidemic upon the very great morbidity and the low mortality. Simple, uncomplicated influenza at this time was looked upon as a disease that was rarely dangerous to life. Studies have shown that after this period there seemed to have been lessened morbidity. As previously stated, nearly all the numerous pandemics at various times have had their origin in Russia and arose in the late autumn or winter months. This pandemic of 1889 and the succeeding severe epidemics in Europe and North America in the years of 1891 and 1892 occurred almost exclusively in the cold weather, the summer remaining free. It is generally believed now, and was at the end of that pandemic, that atmospheric or telluric conditions had nothing to do with the spread. The origin of epidemics following the pandemics seemed to be influenced in their recurrence by the season of the year. It was conceded by observers in that pandemic also that contagion might be carried by merchandise and even flies and healthy individuals.

_1918 Epidemic in Large Cities_

In the city of Boston during the week ending August 28, at the Naval Station at the Commonwealth Pier, 50 cases of influenza occurred and within the next two weeks more than 2,000 were reported in the naval forces of the First Naval District. Of these 5 per cent. developed broncho-pneumonia with a mortality of more than 60 per cent. From here it probably spread to Camp Devens and thence ran rapidly over the country. There can hardly be a question that it spread along the lines of traffic. Up to November 9 there were reported 3,339 cases among the civilian population of Boston. There were 3,430 deaths from influenza, the presumption being that these were due to bronchial pneumonia, although not reported as such. The deaths from all forms of pneumonia were reported as 942, making in all 4,372 deaths from September 7 to November 9. This discrepancy—that is more deaths than reported cases of influenza—is due to the fact that influenza was not made a reportable disease until the date of October 4, fully a month from the time the epidemic appeared. The weather conditions were generally fair and no noted abnormality is recorded as compared with other years. The statement of the Health Department of this city was that, after a practical disappearance of influenza in October, there was a slight recurrence in November and a more pronounced recurrence about the first of December, since which time the cases have slowly but steadily decreased, until at present—December 21—the fatalities attributable to influenza are about 20 daily.

In the city of New York the epidemic first appeared September 18. Up to and including December 27 there were reported to the Department of Health 136,061 cases of influenza and 21,388 cases of pneumonia. The number of deaths since September 18 was 11,725 attributed to influenza in the death certificates filed in the Health Department and 11,601 attributed to pneumonia. The epidemic reached its peak during the week of October 19, slowly subsided and was practically at an end on November 9. While the epidemic is reported as ending on this date, the mortality rate from influenza and pneumonia is still very much above normal. No particular features concerning the meteorological conditions were noted, except that in this city the weather was clear and delightful during the months of September and October when the epidemic was rampant.

In the city of Philadelphia on July 22 the Health Department issued its first health bulletin on so-called Spanish influenza, announcing the possible spread of this disease into the United States. On September 18 a warning was issued against an epidemic, the department starting a public campaign against coughing, sneezing and spitting. On September 21 the Bureau of Health made influenza a reportable disease. At this time the authorities stated an epidemic of influenza was recognized as existing among the civil population of similar type to that found in the naval stations and cantonments; that a large percentage of cases was accompanied by pneumonia; that patients should be isolated and attendants wear masks; that isolation be practiced for a period of ten days after recovery to prevent carriers; that patients be guarded against relapse and that the public be cautioned against large assemblages and crowded places, as well as to avoid coughing, sneezing and spitting. On October 3 the churches, saloons and theatres were closed, funerals were made private and food handlers were required to protect their wares. The number of cases reported from September 23 to November 8 was 48,131, but the Bureau states, from a rough estimate, the number of cases was probably 150,000. The total number of deaths reported was 7,915 from influenza and 4,772 from pneumonia in all its forms, the presumption being that the deaths during this period were due to influenzal pneumonia. The weather condition during this time is recorded as mild and fair.

The influenza cases began to be reported in Cleveland on October 5, and up to December 20, 22,703 cases had been recorded. Certificates recording deaths due to influenza alone numbered 2,497, while pneumonia amounted to 833. The epidemic was at its height in the latter half of October and the weather was spoken of as pleasant fall weather. During the week of October 26 the epidemic reached its greatest height, abated in the week ending November 23, increased later, but showed a drop for the week ending December 21.

The epidemic first reached Chicago on September 21, and from that date on it rapidly increased throughout the city for a period of 26 days until October 17, when it reached its maximum both in the number of deaths from influenza and from pneumonia. On that day the total number of deaths from influenza and from pneumonia reported was 2,395. From September 21 until November 16 there were reported 37,921 cases of influenza and 13,109 cases of pneumonia. On September 8 at the Great Lakes Naval Training Station, which is 32 miles north of the city, an extensive outbreak of influenza occurred. This was 13 days before the outbreak in the city of Chicago itself. Camp Grant, located at Rockford, 92 miles northwest of the city, suffered an outbreak on September 21. A suggestion of the likelihood that influenza was prevalent in this country in a mild and unrecognized form in the spring of this year is shown by the fact that numerous local outbreaks of acute respiratory diseases were brought to the attention of the Health Department of Chicago. These occurred especially in large office buildings and in industrial departments. The total number of deaths from influenza and pneumonia during 14 weeks was 51,915. This would indicate that a very great number of cases were not reported to the Bureau of Health until they died or else there must have been a large number of deaths due to lobar pneumonia. One naturally obtains from these figures the impression that the disease was not recognized for a long time, that the pneumonia must have been called lobar pneumonia, and that the actual figures gathered by this city, as well as others, must have been greatly confused at the onset of the epidemic. It is not unlikely that records from many of the army cantonments and naval stations may be considered from the same viewpoint. Weather conditions were considered normal at the height of the epidemic, the weather being dry. There has been a flare-up of influenza recently, but not in sufficient numbers to justify calling it epidemic.

In the city of Louisville, Ky., the epidemic started September 26, and the total number of cases up to December 21 is reported as being 9,445. Out of this number 772 deaths occurred from pneumonia. No distinction is made here between broncho-pneumonia and lobar pneumonia, but the presumption from the records of other cities at this time is that these were cases of broncho-pneumonia following influenza. The weather was described as being delightful fall weather. The statement is made by the authorities that while the epidemic is still prevalent, it is confined largely to children and is rapidly abating.

The first case in the city of St. Louis was reported about October 7, and up to December 23 there had been 31,531 cases reported to the Bureau of Health. They recorded 1,920 deaths with influenza given as a contributing cause. Preceding the time when the epidemic was at its height the weather was fair and warm, and the statement is made that, “without going into the matter exactly, we have been of the opinion that damp, rainy weather has been a help in controlling the disease.” The opinion was expressed by the Commissioner of Health that the disease had now abated.

No information could be obtained as to when the epidemic first reached the city of New Orleans, but during the months of October and November 43,954 cases of influenza were recorded. Of this number 2,188 died from a combination of influenza and pneumonia. They stated in their health report that during the period from January 1 to December 31 there were 239 deaths attributable to broncho-pneumonia. The weather was mild and on December 24 the epidemic was stated to have abated.

The city of Minneapolis recorded its first case on October 7, but the authorities expressed their belief that a few cases had appeared before that date. Up to December 21, 15,000 cases had been reported to the Bureau of Health and of these there had been 735 deaths from broncho-pneumonia. They had in their city a late, rainy fall and up to that period they had had no cold weather.

The record obtained from the city of San Francisco stated that the epidemic first appeared September 23 and that it was very widespread in that city early in October. There were two invasions and 53,260 cases reported. At the height of the epidemic more than 2,000 cases were reported in one week; 188 deaths occurred from influenzal pneumonia. The following week, after the institution of mask wearing, in which between 80 and 90 per cent. of the population concurred, it was stated that the number of cases decreased to about 200. It was stated that the weather was generally very fair during the epidemic.

From the city of Portland, Oregon, the following information was obtained: The epidemic first appeared October 11, with a second one toward the end of the year. There were 8,079 cases reported, with 658 deaths from influenza and 250 from pneumonia. Weather conditions were stated to be varied, but the health officer believed that during the worst wave the weather was clear and dry, with easterly wind. He believed that a decrease in influenza was noticed immediately after a Chinook wind and warm rain. Similar observations were made by Coutant in Manila.

A weather comparison of 12 large cities, well distributed over the United States, studied during this pandemic of influenza and checked with normal weather during that of many years, shows: Boston, fair with no abnormality; New York, clear and delightful, no abnormality; Philadelphia, mild and fair; Pittsburgh, mild and cloudy; Cleveland, pleasant fall weather; Chicago, normal and dry; Louisville, delightful fall weather; St. Louis, fair and warm-damp, rainy weather later seemed to control the epidemic; New Orleans, mild; Minneapolis, a rainy fall and no cold weather, which is unusual there; San Francisco, generally fair, and Portland, Oregon, clear and dry.

_The Epidemic in Universities and Colleges_

At Bryn Mawr College, in Pennsylvania, an institution devoted to the higher education of women, located within 10 miles of the city of Philadelphia, the epidemic occurred at the beginning of the college year—October 1. This college at the time had an enrollment of 465 students. There were 85 cases of influenza, with an additional 25 who suffered from influenza in their homes. There were no deaths from pneumonia. The weather conditions were clear and warm, and since November 29 there have been no new cases occurring in the college and only three or four of the students have been ill at their homes since that time.

The enrollment at Smith College, Northampton, Mass., was 2,103, and the first case of influenza appeared with the arrival of the students on September 18 and reached its height on September 30. All group gatherings indoors were stopped from October 3 to October 18, and the epidemic was over by October 20. A recurrence began November 15 and continued until December 17. There were 182 cases in the first epidemic and 100 cases in the second. There were only two deaths from influenza pneumonia. During the rise of the epidemic the weather was rainy, followed by good, clear weather. The change in weather conditions seemed to make no difference. The second epidemic was still prevalent when the students left for their holidays.

In Wellesley College, where there were enrolled 1,593 students, the epidemic first appeared on September 18. Up to the middle of December they had had 280 cases. During six weeks of the epidemic 265 cases were reported and only one death occurred from broncho-pneumonia. For the most part, bright and sunny days were present, with only a few cloudy and rainy days. This college has not been without cases since September, but the epidemic lasted only about six weeks.