Читать книгу Studies on Epidemic Influenza: Comprising Clinical and Laboratory Investigations - University of Pittsburgh. School of Medicine - Страница 9

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Reviewing the history of former epidemics and pandemics, I have gained the impression, as have many others, that we are not dealing with any new disease. Further, our knowledge of this pandemic with its high incidence of broncho-pneumonia shows that it is in no way markedly different from that of former manifestations of influenza. One is impressed by the fact that in different outbreaks of this disease of complex symptomatology certain symptoms or complications have been prominent, overshadowing others, and making such complications the striking feature at the time. The failure to recognize that these varying features are merely different manifestations of one disease has resulted in much confusion. The observation made in the last epidemic—and one which can be endorsed during the present plague—is that influenza has been and is the most widespread, rapid and extensive of all diseases. One thing also that attracts attention at the present time is the long period existing between the several pandemics. Whether, as one observer during the present pandemic has stated, it requires a long period for the infection to become active and easily carried, or whether any possible reason can be suggested for these phenomena, admits of no satisfactory explanation. The outstanding feature during this epidemic is the complication of broncho-pneumonia, and yet, from very early times, this complication has been repeatedly spoken of as a striking characteristic. Reviewing the health reports from the large cities of deaths from pneumonia, the presumptive opinion seems justified that almost all, if not all, pneumonias reported as associated with influenza were of the broncho-pneumonia type. The infrequent presence, indeed the rare finding, of lobar pneumonia during this period in Pittsburgh seems to verify the aforesaid opinion. The great frequency and the high mortality of broncho-pneumonia were particularly noted during the present epidemic. During the present epidemic the great mortality among pregnant women was another striking feature, and yet this is by no means new, having been recorded by some of the earliest writers. Such also may be said of the recurrence of the disease in the same patient. One important observation brought out in the study of the pandemic of 1889 to 1892 was that the ordinary infections occurring in the spring and fall known as grippe or La Grippe are in no way connected with the pandemics which have occurred. There seems to be a consensus of opinions among the records of the more recent epidemics, as well as during the present pandemic, that weather conditions in no way influence the spread of the disease. Furthermore, a study of weather conditions throughout the United States, and particularly those of our own city, seem to bear out the truth of this observation. While clinicians during other epidemics expressed their belief in the incident of a primary case producing infection, it has only been during the present one that such an opinion has not been assailed. The large number of military training camps and cantonments have undoubtedly offered splendid opportunity for the spread of influenza. The futility of attempting to control it even under normal conditions is still questionable. Consistent with former reported invasions of the disease, the present epidemic lasted a definite period. This period was about six weeks in most of our large cities, colleges and institutions, extending approximately from October 1 to November 15.

It is imperative to note the accurate clinical observations recorded from the numerous epidemics of the past by men with far less data to go upon than is available at the present day. The high morbidity among the personnel of many of our hospitals and institutions where the infection occurred and the relatively low mortality deserve attention. This may be partly explained by the methods of treatment of those infected, but not entirely. The great likelihood of carriers of influenza, who either are not ill or who are suffering from very mild infection, is an observation also noted by former writers which cannot be ignored. The value of the masks has not been established, although they have been extensively used in many parts of the country. Frequent throat lavage was generally accepted as a rational preventive measure. Relightings of the disease have been noted in most of our cities after the subsidence of the epidemic. Vaccination against influenza is fully discussed in Dr. Haythorn’s paper in this series.

The presence of influenza in San Quentin prison, California, in April, 1918 (Public Health Reports, May 9, 1919); an epidemic of respiratory disease in Chicago in the spring of 1918; the report of Soper of influenza in our army camps in March and April, 1918; the occurrence of influenza in Porto Rico in June; influenza on a United States Army transport from San Francisco, as reported by Coutant, seem to point to the possibility that influenza had a footing in America long before the disease became pandemic. The view held by some that the beginning of influenza was in America, subsequently being transferred to Europe and then reimported here, is worthy of consideration. Coutant believed the disease originated in Manila, others that it traveled from “a permanent endemic focus in Turkestan,” and there are many other theories which attempt to discover the original source of the disease. The question is today an unsettled one. The pandemic of influenza in its severest form swept so suddenly over the world that before the profession realized it or had become stabilized it had changed its character and the great plague was gone. The consequence has been that we have really learned little that is new and have done scarcely more than establish on a firm basis many of the opinions formed after the great outbreak of some 30 years ago. Because transportation is today more rapid than it was at that time, so the spread of the disease has been correspondingly swift. Our modern life, the congregating crowds in theatres, moving-picture houses and in lecture halls, as well as of the men in our training camps, the development of street cars and the more frequent traveling by train—these and many more changes in our mode of living have served to aggravate the conditions favoring the widespread distribution of the infecting agent. A higher proportion of the population was, therefore, attacked than in any previous pandemic, and the period during which the disease was widely prevalent has for the same reason been relatively much shorter.

The characters differed somewhat in different regions, but the evidence shows clearly that we are not dealing with any new disease. It will be years before we are able to fully analyze the data that have been collected from such wide sources and by so large a body of trained men, so that important epidemiological facts may still be forthcoming from the material already at hand. We are too close to the events to get the most helpful perspective, and the object of this report has been to add, in however small a degree, to the general knowledge of this great pandemic as it has appeared to us in Pittsburgh and its surroundings.