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The incidence of invasive Streptococcus pneumoniae and Haemophilus influenzae type b infections in the sickle cell disease population has declined. In this report, we determine the predominant organisms responsible for bloodstream infections in a pediatric sickle cell disease population during the postheptavalent conjugate vaccine era. Central venous access device associated infections are a new burden to efforts aimed at preventing bloodstream infections in this population.

The incidence of pneumococcal disease in sickle cell disease declined significantly with penicillin prophylaxis as well as with the pneumococcal polysaccharide and heptavalent conjugate vaccines. In this report, we describe our experience with pneumococcal bacteremia in pediatric patients with sickle cell disease in the post-heptavalent pneumococcal conjugate vaccine era. Despite established prophylactic strategies, pneumococcal bacteremia continues to occur in patients with sickle cell disease.

Purpose: To prospectively identify all cases of bacteremia in children with sickle cell disease (SCD), establish time to positivity for various microorganisms, correlate clinical findings with microbiology data, and determine the antibiotic resistance pattern of the pneumococcal isolates., Methods: All positive blood cultures from children with SCD followed at the Children's Hospital of Philadelphia from January 1993 through May 2001 were included. Isolates were classified as pathogen or contaminant. Demographic and clinical information was abstracted from the medical records. Time to positivity and antibiotic resistance data were generated in the microbiology laboratory., Results: One hundred forty-one positive blood culture bottles were obtained during distinct febrile episodes. Thirty-nine percent contained pathogens and 61% contained contaminants. The average time to positivity was 17.1 hours in the pathogen group and 29.5 hours in the contaminant group (P < 0.0001). Streptococcus pneumoniae was the most common pathogen (42% of total), with a mean patient age of 3.5 years. Gram-negative rods were the second most common organism (28% of total), with a mean patient age of 8.1 years. Thirty-one percent of the pneumococcal isolates were resistant to penicillin. Thirty-five percent of the pneumococcal isolates grew from children with a focus of infection. Acute chest syndrome was noted in 26% of patients with a positive blood culture for S. pneumoniae. Sixty-seven percent of Salmonella isolates and 50% of Staphylococcus aureus isolates grew from patients who developed osteomyelitis., Conclusions: The average time to positivity for pathogens can be used in conjunction with other factors to determine the length of observation required for children with SCD who present with febrile illness. Chest radiographs should be obtained on children with SCD who are bacteremic with S. pneumoniae. Bone scans should be obtained on children with SCD who are bacteremic with Salmonella or S. aureus.

The purpose of this study was to determine the age-related risks, disease-specific risks, and characteristics of serious pneumococcal infections in children with sickle cell disease (SCD) while penicillin prophylaxis was standard. The clinical experiences of three pediatric sickle cell programs spanning January 1, 1992, to May 31, 1998, were combined. Data were collected regarding the patients followed up and the characteristics of bacteremia and meningitis cases. Forty-seven pneumococcal infections (44 bacteremia, 3 meningitis) among 40 patients with SCD were observed. Forty infections occurred in children with homozygous hemoglobin S (SS) during 4108 patient-years at a median age of 22 months; 7 occurred in double heterozygous hemoglobin SC (SC) children during 1777 patient-years at a median age of 23 months. Ten infections occurred among 9 SS children 5 years or older. Most children in whom infections developed were reportedly taking prophylactic penicillin and when older than 24 months old had received Pneumovax (Merck & Co., Inc., West Point, PA, U.S.A. The following pneumococcal serotypes were identified in 15 cases studied: 6A, 6B, 9V, 14, 15B, 18B, 18F, 19F, and 23F. Infections resulted in five deaths and two strokes. The observed severe pneumococcal infection rate in SS children younger than 5 years was less than that reported before penicillin prophylaxis, supporting routine penicillin prophylaxis in this specific population. The optimal duration of penicillin prophylaxis in older children with SCD remains unknown. The administration of 7-valent Prevnar (Wyeth Lederle Vaccines, Philadelphia, PA, U.S.A.) to children younger than 24 months old with SCD should be beneficial, based on the serotype data.