Читать книгу Studies on Epidemic Influenza: Comprising Clinical and Laboratory Investigations - University of Pittsburgh. School of Medicine - Страница 10

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By J. A. Lichty, M. D.

The epidemics of influenza which have been recorded from time to time during the past few centuries have always contributed an interesting chapter to the history of medicine. The protean character of the disease with its many complications is always an excuse for another attempt at the description of the clinical manifestations of a recent epidemic. This is not, however, the only incentive at the present time for describing the clinical aspect of the disease as it appeared in the epidemic through which we have just passed. The study of the disease from other aspects, such as the pathological, the bacteriological and the physiological, by well-organized groups of workers has made it necessary to co-ordinate, if possible, the clinical findings in every detail with these apparently basic principles. It would be interesting to review here the peculiarly fortunate circumstances which have led to the investigations. On account of the great war many temporary laboratory organizations which otherwise would not have existed were in operation, and these organizations, moreover, were keen to undertake any laboratory problem which might arise. The present epidemic presented the opportunity, and that the work was taken up with great enthusiasm is evidenced by the reports coming from the various army hospitals, base hospitals and civilian hospitals throughout the world. The permanent laboratories connected with medical schools and with institutions for medical research took up the problems with equal endeavor. This brief reference is made only to call attention to the fact that from such organizations a great mass of information has come which must be critically reviewed and coordinated before it can add to the permanent fund of our knowledge of the disease under consideration.

The material upon which the following clinical observations have been made is peculiarly adapted to review because it consists of two distinct groups of patients which were admitted to the Mercy Hospital. One group of 153 men was composed of soldiers between the ages of 18 and 23, which had been recently inducted into the Student Army Training Corps, and were living in barracks in the immediate vicinity of the hospital. Another group consisted of civilians (394), ranging from youth to old age, which came from various parts of the city and surrounding towns and country. The first group came to the hospital early, or as soon as the disease was recognized; the second group came usually after several days of illness had elapsed, or when a complication had already arisen. Many of this group had been ambulatory cases for the first part of the disease. The entire number of patients admitted to the Mercy Hospital from the first admission, September 21 to December 1, the end of the quarantine, was 547. After December 1 very few simple influenza cases were admitted. These 547 cases form the basis of the observations which will be referred to in this paper.

From the last great epidemic or pandemic of influenza, that of 1889 and 1890, have come clinical descriptions which should be reviewed before speaking of the clinical manifestations which have characterized the present epidemic as shown in the two groups studied.

One of the best descriptions of that epidemic was given by Dr. O. Leichtenstern in Nothnagel’s Encyclopedia of Practical Medicine. This contribution, among many others, describing the epidemic of 1889 and 1890 is one of the first to refer to the Pfeiffer bacillus as being etiologically associated with the disease. It differs, therefore, greatly from descriptions of previous epidemics. Leichtenstern says: “The typical influenza consists of a sudden pyrexia of from one to several days duration, commencing with a rigor, and accompanied by severe headache, generally frontal, with the pains in the back and limbs, by prostration quite out of proportion to other symptoms and marked loss of appetite.” He continues by saying that to these characteristic symptoms may be added the catarrhal phenomena arising from the affection of the respiratory tract, particularly the upper (coryza) and “occasionally” the lower, the trachea and bronchi. This description is so in accord with the symptoms of uncomplicated influenza as found in the present epidemic that very little need be added. Any difference which may occur in the description of the disease is likely to be accounted for by the peculiarity of onset, whether in the upper or lower respiratory tract, and by the different ways of interpreting complications which may have arisen. It is evident from this description that the upper respiratory tract was affected more generally than the lower in the epidemic of 1889 and 1890. In the present epidemic it can safely be said that the reverse was the usual state of affairs. It was a rather unusual occurrence when the affection was limited only to the nose, pharynx, larynx, trachea and larger bronchi. A very large number, no doubt, had a peculiar œdema, a so-called “wet lung,” which we shall discuss later; others went on to a capillary bronchitis or a bronchiolitis, and a large number had broncho-pneumonia. This sequence we shall attempt to show in the statistics at hand. In some cases the lesion in the lower respiratory tract seemed to be primary, there having been no initial coryza. At least none was observed and no history was obtained.