PNEUMONIA IN NORTH-WEST LONDON, 1942-4: I. BACTERIAL PNEUMONIAS* BY

-In a study of cases of primary pneumonia admitted to a large general hospital the findings will depend not only upon the prevalent infections in the area served but also upon the criteria of admission to hospital and the facilities for home treatment. Most published investigations of pneu-monia until 1939 were confined to lobar pneu-monia, the world literature dealing with which has been exhaustively reviewed by Heffron (1939). During and just before the war years, however, an increasing number of papers appeared concern-ing primary pneumonias due to other than the classical bacterial agents, and the conditions loosely termed " atypical " or " virus " pneumonia became widely recognized. There were many reasons for this, of which the most important were the improved prognosis for bacterial pneumonias afforded by modern chemotherapeutic agents, the increasing use of radiography, and the tendency for the early hospital treatment of relatively mild chest conditions among persons in the armed Forces. The great bulk of such investigations were made in the U.S.A., frequently on Services per-sonnel, and they have been reviewed by Reimann (1947). The relative incidence of bacterial and non-bacterial agents in pneumonia among the general population in this country is far from cer-tain. Even in two years in the U.S.A. estimates of the incidence of " viral " ' pneumonia ranged from 15 per cent of pneumonia admissions (Reimann and others, 1942) to 45 per cent (Good-rich and Bradford, 1942) and approximately 70 per cent (Reimann, 1943). It seems therefore to be of interest to present the results of a survey of primary pneumonia cases admitted to the Central Middlesex County Hospital during the perio