Pneumococcal Pneumonia; Diagnostic, Epidemiologic, Therapeutic and Prophylactic Considerations

The past 50 years have witnessed striking changes in the physician's perceptions of the clinical syndrome of pneumonia in general and of pneumococcal pneumonia in particular. Advances in basic and applied microbiology have contributed to increased awareness of the diversity of infectious agents which may invade the lung and of the complex interactions of viruses and bacteria in the pathogenesis of pneumonia. Concomitant with these increments to knowledge, the introduction of potent antimicrobial drugs which have dramatically reduced the morbidity and mortality of many forms of pneumonia has had a profound effect on professional attitudes. Paradoxically, because of the improved prognosis of such illnesses, there has been a diminution of effort on the part of many physicians to seek their cause routinely and, thereby, to maintain knowledge of their clinical and epidemiologic features. In the late 1930s, the simple step of substituting sulfonamides, effective against pneumococci of any capsular type, for treatment with type-specific antiserum, which required the isolation and capsular typing of the inciting organism for its rational and effective use, had an initially negative impact on the bacteriologic diagnosis of pneumococcal pneumonia. This trend was heightened greatly a few years later by the introduction of penicillin as the drug of choice for treating pneumococcal infections. For those desirous of continuing to study the causes and epidemiology of pneumonia, the problem was compounded by the increasing difficulty in obtaining for the laboratory the necessary pneumococcal typing sera, which had been by-products of the now discarded therapeutic antisera. This combination of circumstances, together with the markedly improved prognosis of many bacterial infections brought about by new drugs introduced at mid-century, led many physicians to believe that, in most uncomplicated cases of pneumonia, studies to estab lish their cause were of doubtful value. An example of this outlook may be found in the following statement published in 1956: “In cases of pneumonia in the age group 15-60 without significant coexistent disease, it is felt that routine bacteriologic studies are unnecessary.” 1 Bridge RC The value of bacteriological studies in the age group 15-60. Dis Chest. 1956; 30: 194-201 Abstract Full Text Full Text PDF PubMed Scopus (2) Google Scholar Similar views were voiced a decade later in the Lancet: “Few physicians order a blood-culture on all patients with pneumonia—and this is probably for patients' good—and no one, so far as we know, types pneumococci routinely.” 2 Annotations. Pneumococcal pneumonia. Lancet 1968; 1:1360-61 Google Scholar These comments suggest a nihilistic view of the potential benefit that might accrue from studies of the etiology and epidemiology of pneumonia.