Frequency of bacteremia in patients with sickle cell disease: a longitudinal study

Bacterial infections in sickle cell disease (SCD) are associated with major risks of morbidity and mortality. Here, we describe the occurrence of bacteremia in SCD patients from 2000 to 2017. This is an observational study which included children and adults with SCD and fever and had confirmed positive blood cultures. During the study period, there were 1095 SCD patients with 17,053 blood cultures. Of all the patients, 699 (63.8%) were children and 396 (36.2%) adults with 576 (52.6%) males and 519 (47.4%) females. The mean age ± SD was 17.8 (± 14.7), and a median age (IQR) of 13.6 (6.8-23.5) years. The mean (SD) follow up was 7.4 (5.4) years and the total number of patient-years was 8069.1 years. Out of the 1095 patients, 91 (8.3%) had bacteremia with 35 (38.5%) children and 65 (61.5%) adults (p = .079). The rate of bacteremia in all patients, children, and adults were 1.5 (95% CI: 1.3-1.8), 0.6 (95% CI: 0.4-0.8), and 2.4 (95% CI: 1.8-3.1) per 100 patient-years, respectively. The risk of Gram-positive bacteremia was 0.5 (96% CI: 0.36-0.69) in all patients, 0.1 (95% CI: 0.06-0.20) in children, and 1.4 (95% CI: 1.0-2.0) in adults per 100 patient-years. The risk of Gram-negative bacteremia was 1.0 (95% CI: 0.81-1.3) in all patients, 0.6 (95% CI: 0.4-0.8) in children, and 2 (95% CI: 1.5-2.7) in adults per 100 patient-years. The risk of Gram-negative bacteremia was higher than Gram-positive bacteremia in children (p < .001) but not in adults (p = .113) and adults had higher risk in general than children. In this study of SCD cohort, 8.3% had bacteremia with predominant Gram-negative infections. Bacteremia was more frequently encountered in the adult age group. Further studies are needed to verify the findings and explore possible reasons predisposing SCD patients to bacteremia.