Impact of a rapid molecular test for positive blood cultures from neonatal intensive care patients on clinical management: a retrospective audit.

Abstract

Both Staphylococcus aureus and coagulase negative Staphylococci are common causes of late-onset neonatal sepsis in the neonatal intensive care unit (NICU), usually relating to intravascular access device infections. This project aimed to review the impact on antimicrobial treatment and clinical outcome in the NICU setting, of the introduction of the Xpert MRSA/SA BC test (Cepheid, USA) for the identification of staphylococci in blood cultures. A retrospective audit was carried out of the pre- and post-intervention periods; the intervention was the introduction of the Xpert MRSA/SA BC test. In total, 88 neonates had positive blood cultures with Staphylococcus spp., comprising 42 neonates in the pre-intervention and 46 in the post-intervention groups. The pre-intervention group had a higher birth weight (1.541kg vs. 1.219kg, p=0.05) and higher platelet count (288 vs. 224×109/L, p=0.05). There was a trend towards a shorter duration of antimicrobial therapy in term infants and in the length of admission; however, this was not statistically significant (p=0.2). All of the nine infants post-intervention with significant bacteraemia (S. aureus =3, CoNS =6) were changed to the optimal antimicrobial at the time the result was available. This study shows that the introduction of the Xpert MRSA/SA BC test can lead to a reduction in the length of admission and duration of antimicrobials in term infants; however, the difference was not statistically significant. All nine infants with clinically significant bacteraemia were treated with the appropriate antimicrobial when the Xpert MRSA/SA BC test result was available.