Capsular Types and Outcome of Bacteremic Pneumococcal Disease in the Antibiotic Era

Abstract

Between October 1967 and February 1970, a total of 325 adults with bacteremic pneumococcal disease or an extrapulmonary focus or both were admitted to the Cook County Hospital and were investigated for infecting pneumococcal capsular type and outcome of the disease. Of these, 262 (81%) patients had bacteremic pneumococcal pneumonia only and 63 (19%) had an extrapulmonary focus of infection with or without pneumonia. Eight capsular types, numbers 8, 4, 5, 12, 3, 1, 7, and 9 in decreasing frequency, accounted for two thirds of the infections. No one pneumococcal type predominated. The overall case fatality rate, irrespective of type or antibiotic treatment, was 28%. All patients received treatment with antibiotics, usually penicillin, tetracycline, or erythromycin, alone or together with other antibiotics. Deaths were more frequent in older patients, and in patients with an extrapulmonary focus of infection or complicating chronic disease. These findings point up the unchanged high case fatality rate from bacteremic pneumococcal infection. For the control of pneumococcal disease, a polyvalent pneumococcal polysaccharide vaccine would have broad application, especially among high-risk groups.