Invasive pneumococcal disease among children with and without sickle cell disease in the United States, 1998 to 2009

Background: Children with sickle cell disease (SCD) are at increased risk of illness and death from invasive pneumococcal disease (IPD). The introduction in 2000 of the 7-valent pneumococcal conjugate vaccine and penicillin prophylaxis for children with SCD has greatly reduced the incidence of IPD in this population. However, a recent report suggested an increase in cases of IPD in children with SCD. Methods: Using data from Active Bacterial Core surveillance, we analyzed trends in hospitalizations, mortality and serotype among children with SCD compared with other children. We used neonatal screening data to estimate SCD population denominators for each Active Bacterial Core surveillance site. Results: From 1998 to 2009, 3069 cases of IPD occurred among African-American children less than 18 years of age in the Active Bacterial Core surveillance catchment area. Of these, 127 (4.1%) had SCD identified by medical chart review and 185 (6.0%) had 1 or more IPD risk factors, excluding SCD. Rates of IPD among children with SCD declined by 53% (1118 vs. 530 per 100,000) whereas the overall rates among African-American children declined by 74% (54 to 14 per 100,000). For all time periods, children with SCD and IPD were more likely to be hospitalized (84%-92% vs. 31%-56%) and more likely to die (6%-17% vs. 1%-2%) than children with no risk factors. Conclusions: Although the rate of IPD in children with SCD has dropped dramatically since 7-valent pneumococcal conjugate vaccine introduction, the rate of IPD in children with SCD remains higher than that of the general population of African-American children, pointing to the need for more effective prevention efforts to prevent IPD in children with SCD.