Constancy of distribution of serogroups of invasive pneumococcal isolates among children: Experience during 4 decades

Serogroups of pneumococci that caused bacteremia or meningitis in children were examined from 1981 through 1998 at Boston City Hospital/Boston Medical Center. There were 410 episodes of pneumococcal bacteremia (13-36 cases pe r year), of which 14 occurred in human immunodeficiency virus (HIV)-infecte d children and 9 occurred in children with sickle-cell disease. The 7 most common serogroups were 14 (30.7% of isolates), 19 (11.7%), 6 (11%), 18 (10. 7%), 9 (7.6%), 23 (7.3%), and 4 (5.6%). The rate of episodes due to serogro ups 4, 6, 9, 14, 18, 19, and 23 ranged from 80% to 91.9% during the study p eriod. The rate of episodes due to serogroups 4, 6, 14, 18, 19, and 23 was 84.6% among patients with HIV infection, 100% among patients with sickle-ce ll disease, and 94.1% among the 18 patients for whom cultures of CSF specim ens revealed pneumococcal meningitis. The results demonstrate that type 14 was the dominant pneumococcal serogroup responsible for invasive disease th roughout the Is-year study period and that serogroup distribution overall r emained constant. A comparison of these findings with historical pediatric data from our institution showed serogroup stability dating back to 1957.