Methods: We conducted a retrospective chart review of all pediatric patients admitted to our children’s hospital from 2011-2014 who had a blood culture positive for SA. An episode of bacteremia was defined as positive cultures occurring during a distinct hospital encounter, or separated by a minimum of 14 days. Each bacteremia episode was classified as CA, HCA, or HA based on predefined criteria involving time of blood culture collection, and patient comorbidities. Risk factors for bacteremia, underlying conditions, concomitant infection sites, antibiotic susceptibility profile, and outcomes were recorded. Statistical analysis was done using R software and GraphPad Prism, and p<0.05 was considered significant.
Results: Forty-four children had 63 episodes of SA bacteremia over the 3-year period. Two of these episodes were considered contaminants by the treating team and were excluded. History of prior SA infection varied significantly between groups (HCA 77%, HA 45%, CA 0%; p=0.0005), as did history of prior SA bacteremia (HCA 51%, HA 15%, CA 0%; p=0.004). Concomitant osteomyelitis was seen in 83% of CA bacteremia cases, compared with 0% of the HCA and HA cases (p<0.001). CA SA bacteremia isolates were more likely to be clindamycin susceptible (100%) compared with the HCA (42%) and HA (60%) isolates (p=0.028). Patients with HCA SA bacteremia were more likely to be readmitted in the next 30 days (57%), compared with 17% for the CA group, and 20% for the HA group (p=0.01).
Conclusion: CA, HCA and HA pediatric bacteremia cases differ in their clinical characteristics, antibiotic susceptibility and outcome measures. These data support the clinical relevance of these classifications in the pediatric population.