Hemolytic Streptococcal Pneumonia and Empyema; A Study of 55 Cases With Special Reference to Treatment

Abstract

It is now well established that at least 85 to 90 per cent of all cases of pneumonia are due to pneumococcal infections and, of these, at least 80 per cent are caused by a relativelv small number of specific types (f, II, III, V, V II, VIII, and XIV). Other mnicro-organisms, such as stircptococclfs lieo1lyt)ticts, staphlylococcuts iurceus, bacilluts F;'iedldndcer, are usually responsible for the remaining cases. The hemolytic streptococcus is the cause of between 3 andl 5 per cent of all cases of pneumonia, although its frequency varies from time to tiimie, depending somewhat upon the predisposing factors and the existence of epidemics of respiratory infections which create favorable conditions for the invasion of the organisms.As a part of an investigation of hemolvtic streptococcal infections! 55 cases of infection of the lungs and pleura were stuclied. In particular, we were concerned with the determination of the specific tvl)es of hemolytic streptococcus causing these infections and the effect oi the newer chemotherapeutic agents in treatment. ANA\LYSIS OF CASES.Etiolo-gV (111d Predisposiiig Factors.Hemolytic streptococcal pneumonia occurs most often following epiclemic influenza or measles; less often it is associated with pneumococcal infection or other inflammatory lesion of the lungs. In 10 of the 55 cases which were studied, the infection of the lungs, insofar as could be ascertained, was primary. That is to say, it occurred without any preceding illness. In 13, the pneumonia was preceded bv an infection of the upper respiratory tract and, in an additional 10, it was associated with pneumococcal infection. Other predisposing factors are listed in Table I.