Format

Send to

Choose Destination
Infect Dis (Lond). 2018 Sep;50(9):660-665. doi: 10.1080/23744235.2018.1451917. Epub 2018 Mar 16.

Coagulase-negative staphylococcal bacteraemia in cancer patients. Time to positive culture can distinguish bacteraemia from contamination.

Author information

1
a Diseases Control and Prevention Center , National Center for Global Health and Medicine , Tokyo , Japan.
2
b Department of Infectious Diseases , Shizuoka Cancer Center , Shizuoka , Japan.
3
c Clinical Research Promotion Unit , Clinical Research Support Center, Shizuoka Cancer Center , Shizuoka , Japan.

Abstract

BACKGROUND:

Coagulase-negative staphylococci (CoNS) are the most common contaminants of blood cultures, however, we sometimes have difficulties in determining their clinical significance. It is still controversial that there is a significant difference between the contamination group and the true bacteraemia group in the time to positivity (TTP) of blood cultures. We validated the relationship between a TTP and the presence of CoNS bacteraemia in cancer patients by using an objective, non-judgmental definition for CoNS contamination.

METHODS:

We retrospectively reviewed 175 sets of blood cultures drawn from 95 patients that yielded CoNS from October 2011 to March 2013. We considered as contamination if an isolate of CoNS was identified in one out of multiple sets of blood cultures. We investigated the TTP, the threshold values and corresponding likelihood ratios to distinguish CoNS bacteraemia from contamination.

RESULTS:

The median TTP in CoNS bacteraemia group was significantly shorter than that in contamination group (14 h 45 min and 20 h 31 min, respectively, p = .0157). A TTP of ≤16 h had a specificity of 83% for predicting CoNS bacteraemia, and that of >20 h had a sensitivity of 86% for predicting CoNS contamination.

CONCLUSIONS:

We validated that the median TTP in CoNS bacteraemia group was significantly shorter than that in their contamination group, and that a TTP of ≤16 h was associated with CoNS bacteraemia, while that of >20 h was associated with CoNS contamination, if evaluated with an objective, non-judgmental definition for CoNS contamination.

KEYWORDS:

A time to positivity; Bacteraemia; Cancer patients; Coagulase-negative staphylococci; Contamination

PMID:
29544362
DOI:
10.1080/23744235.2018.1451917
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Taylor & Francis
Loading ...
Support Center