Backgrounds:

Blood cultures are commonly performed in hospitalized children with febrile illness in order to identify bacteremia.

Methods

This is a study of bacteremia cases among children hospitalized in a Greek tertiary pediatric department.

Results:

In the 11-year study period, 18,480 children were hospitalized. During the first 48 hours after admission, one or more blood cultures were obtained from 6,891 children with acute febrile illness; 130 (1.9%) had a positive culture considered as representing "true bacteremia" (2.1% in 2010-2013, 1.5% in 2014-2017 and 1.9% in 2018-2020). In addition, 120 positive blood cultures were considered as representing “contamination”. Microorganisms, such as coagulase-negative staphylococci, Staphylococcus epidermidis, S. hominis, Streptococcus viridans and Micrococcus spp., typically considered as contaminants from the skin, were included in the analysis only if they had been isolated in ≥2 blood cultures during the same hospitalization. In each true bacteremia case the recovered pathogen was reported once, even if detection was confirmed in >1 blood cultures. The seven most frequently isolated pathogens per time-period are presented in Figure 1. S. aureus was the most common pathogen isolated followed by Brucella spp. Overtime, no significant change in the frequency of a specific pathogen was observed.

Figure 1. Distribution of recovered bacterial pathogens during the study period

Conclusions/Learning Points:

Among hospitalized children with possible bacteremia the percentage of positive blood cultures remained low. S. aureus was the most frequently isolated pathogen. Prior antibiotic treatment, relatively low bacterial load, or difficulties in the isolation of specific bacteria may contribute to the low percentage of identification of the etiologic agent.