Affiliations: Hagateaching Hospital, Juliana's Children's Hospital,
The Hague, The Netherlands
Note: [] Corresponding author: Esther Jean d'Haens, MD, Hagateaching
Hospital, Juliana's Children's Hospital, Sportlaan 600, 2566 MJ, The Hague, The
Netherlands Tel.: +31 702107222; Fax: +31 702106168; E-mail:
[email protected]
Abstract: Background/aim: To minimize the use of antibiotics in the neonatal
unit, it is crucial to know the time needed for a blood culture to become
positive. With the development of newer automated blood culture systems, the
time needed to detect a positive culture is said to be reduced to 48 hours. The
aim of this study was to determine the time at which neonatal blood culture
results become clinically available to the attending neonatologist. Design and methods: In an eighteen-months-period prospective
study we collected 361 blood cultures from neonates admitted to our neonatal
unit. Time to positivity (TTP) (the time between culture sampling and the
moment the neonatologist received the results) was determined. Incubation time
(time actually spent in the Bactec machine) was automatically registered. Results: 72 out of 361 blood cultures were positive (20%).
93% (67/72) of the positive cultures had a TTP of less than 48 hours. One
sample had a TTP of 50 and one of 53 hours. Three samples had an incubation
time of more than 94 hours. A total of 99% (68/69) of the remaining cultures
were positive within 30 hours of incubation. Conclusion: This study demonstrated that 93% of blood
cultures results are determined by 48 hours. Incubation time in the Bactec is
consistent with reliable detection of pathogen microbes by 30 hours. If effort
is made to improve logistics TTP can further be reduced to 30 hours resulting
in further reduction of antibiotic usage in neonatal intensive care units.
Keywords: Neonatal bacteremia, blood culture, time to positivity, bacterial sepsis
