Racial differences in the epidemiology of invasive pneumococcal disease (IPD) have been widely recognized, but the impact of conjugate pneumococcal vaccine (PCV) introduction in 2000 on these differences has not been extensively studied.
IPD episodes in 5 Tennessee counties from January 1995 through December 2002 were collected prospectively using the Centers for Disease Control and Prevention’s Active Bacterial Core Surveillance system (ABCs). Trained nurses collected clinical data, and antibiotic susceptibility testing was performed on available isolates.
Before vaccine licensure, IPD rates were highest in children younger than 2 years and in blacks. The disparity in IPD rates between blacks and whites younger than 2 years of age substantially diminished after PCV introduction. In 1999, the IPD rate in black children younger than 2 years was 340.2 per 100,000, representing 176.5 more events per 100,000 than in white children (P < 0.001). In 2002, this rate had decreased 83% to 57.4 per 100,000, similar to the rate in white children (39.6 per 100,000; P = 0.31). Before vaccine licensure, a higher percentage of isolates from whites were antibiotic-nonsusceptible. In 2002, the proportion of antibiotic-nonsusceptible pneumococcal isolates was similar in whites and blacks of all ages for the first time during the study period (P > 0.05 for separate comparisons of penicillin, cephalosporin and erythromycin nonsusceptibility). These changes occurred despite a lower PCV vaccination coverage in Tennessee in blacks than in whites (31.2% versus 47.6%).
With conjugate pneumococcal vaccine introduction in Tennessee, racial differences in the incidence rates of IPD have largely been eliminated, particularly in young children.
From the Departments of *Medicine, †Pediatrics, ‡Biostatistics, and §Preventive Medicine and the ||Center for Education and Research on Therapeutics, Vanderbilt University School of Medicine; the ¶Tennessee Department of Health; and #Geriatric Research and Education, Veterans Affairs, Tennessee Valley Healthcare System, Nashville, TN
Accepted for publication April 5, 2004.
Supported in part by ATPM/CDC Cooperative Agreement TS-0825 and CDC Emerging Infections Program Cooperative Agreement U50/ CCU416123. T.V.H. received support from grants UO1HL72471 and KO8 AI 001582. N.B.H. received support from NIH Vanderbilt Mentored Clinical Research Scholar Program K12 RR-017697.
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