Pneumococcal Infections

THE PNEUMOCOCCUS (Streptococcus pneumoniae) remains a major cause of pneumonia, meningitis, and otitis media in the United States and in other parts of the world. Pneumococcal infection represents an important medical problem, not only because of its common occurrence, but also because too many deaths still occur from these serious infections despite the availability of effective antimicrobial drug treatment. Although case fatality rates in bacteremic pneumonia and meningitis have decreased markedly in the antibiotic era compared with those of the preantibiotic era, they remain unexpectedly high. This review aims to define the incidence and clinical significance of pneumococcal pneumonia and other pneumococcal infections in the US population and to identify those groups of persons who seem at highest risk for morbidity and mortality. Although pneumococcal infections occur commonly, their precise incidence is not known.1,2Epidemiologic studies aimed at establishing the incidence of pneumococcal infection in differing populations have been