Rapid Diagnostics Reduce Time to Optimal Antimicrobial Therapy in Children

Pediatric Patient drinking water
Pediatric Patient drinking water
Time to optimal antimicrobial therapy for positive blood cultures was assessed in a pediatric population.

Rapid diagnostics may reduce time to optimal antimicrobial therapy and unnecessary antibiotic use without worsening clinical outcomes, according to a study recently published in The Pediatric Infectious Disease Journal.

Optimizing antimicrobial therapy reduces broad-spectrum antibiotic use, healthcare costs, and antimicrobial resistance. Antimicrobial stewardship promotes the selection of effective and safe antimicrobials. Recently, rapid diagnostics have been shown to facilitate fast and accurate identification of bacteria, yeast, and certain antibiotic-resistance genes while also informing optimal antibiotic selection before susceptibility results are available. These rapid diagnostics include matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) and multiplex polymerase chain reaction (mPCR). 

When combined with antibiotic stewardship programs (ASPs), MALDI-TOF and mPCR may decrease mortality, healthcare costs, and hospital length of stay while also reducing inappropriate antibiotic use; unfortunately, data from use of these diagnostics in pediatric populations are limited. Therefore, this pre-/post-intervention study assessed the impact of mPCR and MALDI-TOF on ASP-guided antimicrobial prescribing and related clinical outcomes for children with positive blood cultures. 

The pre-intervention period was 2012 and the post-intervention period, after progressive ASP expansion and deployment of MALDI-TOF and mPCR, was 2015. Time to effective and optimal antimicrobial therapy was evaluated using Cox proportional hazards regression. Participants included pediatric patients up to age 21 years with positive monomicrobial blood cultures (242 in 2012 and 192 in 2015) at the Ann & Robert H. Lurie Children’s Hospital of Chicago.  

Results showed that time to optimal therapy was reduced post-intervention (73.8 hours) compared with pre-intervention (48.8 hours; P<.001). Additionally, time to organism identification was also reduced post-intervention (55.6 hours) compared with pre-intervention (29.5 hours; P<.001). There was no difference in time to effective therapy or clinical outcomes when pre- and post-intervention periods were compared (P=.782).

Duration of unnecessary antibiotic use for probable contaminants was reduced from 43.1 hours pre-intervention to 29.7 hours post-intervention (P=.027), duration of use of vancomycin for methicillin-sensitive Staphylococcus aureus was reduced from 54.0 hours to 41.3 hours (P=.008), and duration of use of nonpenicillin/ampicillin antibiotics for group A and B Streptococcus and Enterococcus faecalis was reduced from 87.2 hours to 33.4 hours (P<.001). 

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Overall, the study authors concluded that “MALDI-TOF and mPCR with ASP-supported interpretation of rapid diagnostic data led to more expeditious optimization of antimicrobial therapy and decreased broad-spectrum antimicrobial use for several organisms.” 


Reuter CH, Palac HL, Kociolek LK, et al. Ideal and actual impact of rapid diagnostic testing and antibiotic stewardship on antibiotic prescribing and clinical outcomes in children with positive blood cultures [published online May 10, 2018]. Pediatr Infect Dis J. doi: 10.1097/INF.0000000000002102