Although there remains some difference of opinion as to the relation of influenza to pneumonia, the majority of observers concur in regarding pneumonia as a complication and this would seem to be the only logical interpretation of the facts available. The same may be said with respect to purulent bronchitis and bronchiectasis. It is of considerable significance in this connection that pneumonia following influenza presents no uniform clinical picture, no uniform bacteriology and no uniform pathology. Whether the predisposition of patients with influenza to contract pneumonia is preponderantly due to lowering of general resistance to infection by the extremely prostrating effect of the disease and the inhibition of leucocytic defense, or to a destruction of local resistance against bacterial invasion by reason of profound injury to the bronchial mucosa, or to a combination of both factors, is difficult to say. It seems most probable that both are concerned. At any rate it seems clear that in the presence of influenza a considerable variety of organisms which under ordinary conditions do not find lodgement in the lungs are able to gain access to the lower respiratory tract and produce pneumonia. CHAPTER III SECONDARY INFECTION IN THE WARD TREATMENT OF INFLUENZA AND PNEUMONIA EUGENE L. OPIE, M.D.; FRANCIS G. BLAKE, M.D.; JAMES C. SMALL, M.D.; AND THOMAS M. RIVERS, M.D. One of the most pressing problems that presented itself in the care of influenza and pneumonia patients in the army cantonments during the recent epidemic was the danger of secondary contact infection because of the overcrowding of the base hospitals, nearly all of which were taxed far beyond the limits of their capacity. That this danger was very real was fully demonstrated by certain studies in ward infection that this commission was able to make at Camp Pike[49]. It is the purpose of the present section of the report to present these studies and to discuss the means whereby this danger may be most successfully met.