Risk Factors for Persistent Staphylococcus aureus Bacteremia in Children.

Background: Staphylococcus aureus is a leading cause of pediatric bacteremia. Persistent S. aureus bacteremia (SAB) is associated with increased morbidity and mortality in adults and children. Risk factors for S. aureus bacteremia have been well established, but there is a limited understanding of the factors that contribute to the development of persistent SAB in children.

Methods: This is a single-center retrospective secondary analysis of a prospective observational study of pediatric patients hospitalized with S. aureus infection over a 3.5-year period at a large, quaternary, children's hospital.

Results: Two hundred fifty-nine children with confirmed S. aureus infection were enrolled in the study. Sixty-five of these were found to have bacteremia, with 28 (43%) developing persistent bacteremia. Patients with persistent SAB were culture-positive for a median of 3.5 days compared with 1 day for those without ( P ≤ 0.001). Children with persistent SAB were more likely to have an identified osteoarticular source of infection (93%, n = 26 vs. 62%, n = 23; P = 0.008) and had a shorter median duration to culture positivity than those without persistent SAB (16 hours vs. 20 hours; P ≤ 0.001). In addition, children with persistent SAB had higher median values of presenting erythrocyte sedimentation rate, peak erythrocyte sedimentation rate, presenting C-reactive protein and peak C-reactive protein. Not surprisingly, hospital length of stay was longer in children with persistent SAB compared with those without.

Conclusions: These findings suggest that a shorter time to culture positivity, osteoarticular infection, and higher presenting and peak values for select inflammatory markers are potential risk factors for persistent SAB in children.