Serotypes of Streptococcus pneumoniae isolated from blood cultures at Boston City Hospital between 1979 and 1982.

Serotypes of pneumococci causing bacteremia were examined from January 1979 through December 1982. Of the 271 isolates recorded, 52% were from adults and 48% were from children. The rate of pneumococcal bacteremia for adults was 2.67 cases per 1,000 admissions; rates were not calculated for pediatric patients. The six most common pediatric types or groups (14, 19, 18, 6, 4, and 9) accounted for 90% of the total pediatric isolates, and the six most common adult types or groups (12, 9, 8, 4, 3, and 6) made up 55.3% of the total adult isolates. More than 96% of the pneumococcal types isolated from the blood cultures of pediatric patients are present in the 14-valent pneumococcal vaccine, compared with 72.7% of the adult isolates. The results demonstrate that most cases of pneumococcal bacteremia are caused by capsular types or groups present in the current vaccine and that minor changes in the types of pneumococci causing bacteremia have occurred during the past decade.