Reviewed by Sanchi Malhotra MD, University of California Los Angeles
Patel and colleagues conducted a retrospective review of all positive bacterial blood cultures at a pediatric healthcare system between 3/2021-6/2022. Blood cultures were processed using automatic continuous monitoring system (BACTEC), and isolates were identified using MALDI-ToF. Each culture was classified as a bloodstream infection or contaminant via manual review of the patient chart, based on the treating team’s discretion to simulate real world practice.
The study identified 1068 positive cultures, of which 71% were treated as BSIs and 29% were contaminants. Contamination was associated with peripheral cultures (90%) and low volume.
Among patients with BSI, 97.1% had one of the following characteristics: age <90 days, fever or hypothermia, hypotension, a central line, or severe neutropenia. Of the 22 cases not having these criteria, 21 had a primary SSTI or other primary infection where the blood culture would not have changed management.
78% and 93% of BSIs showed positivity within 24 and 36 hours respectively. Among patients with fever and severe neutropenia, 100% were positive within 36 hours. Growth of high likelihood pathogens were less likely to be associated with prolonged time to positivity.
This study can help guide a few decision points in pediatric hospitals looking to implement blood culture stewardship. A simple algorithm going through the above characteristics and suggesting against blood cultures in patients not meeting them could reduce unnecessary cultures, contamination, and potentially CLABSI rates. The study also found a high contamination rate associated with peripheral cultures, which is contrary to adult data finding a higher rate of contamination with CVC cultures, but may be intuitive when considering the potential difficulty of obtaining sterile cultures in children. The study also supports limiting infant and fever and neutropenia rule outs to 36 hours in an era where most hospitals have continuous monitoring systems for blood cultures, rather than manual review of plates which created the standard 48 hour rule out. Most antibiotics given for rule outs will cover the patient through those last 12 hours as a further failsafe and this could help reduce length of stay and healthcare costs.
Reference:
Pratik A Patel, Lydia Lu, Miguel A Locsin, Allyson Dalby, Preeti Jaggi, Characteristics Associated With Positive Bacterial Blood Cultures in Pediatrics, Journal of the Pediatric Infectious Diseases Society, Volume 15, Issue 3, March 2026, piag016, https://doi.org/10.1093/jpids/piag016
