Time to identification of positive bacterial cultures in infants under three months of age hospitalized to rule out sepsis.

OBJECTIVE

To calculate the culture incubation required to determine bacteremia or meningitis in infants younger than three months of age hospitalized from the community following a full septic work-up for fever without focus.

DESIGN

Retrospective chart review.

SETTING

Large, urban, paediatric tertiary care hospital.

PATIENTS

All previously healthy infants younger than three months of age with positive blood and/or cerebrospinal fluid (CSF) cultures admitted from the emergency department to the general paediatric and infectious disease wards from January 1990 to December 1996.

METHODS

The charts of all patients with positive blood and CSF cultures (excluding coagulase-negative staphylococcus) were reviewed to determine the time at which the positive culture was identified. Organisms were considered pathogenic if a clinical decision was made to treat the organism with a therapeutic course of antibiotics.

RESULTS

Of 1235 infants admitted, 5.5% were bacteremic and 1.9% had bacterial meningitis. In 34% of patients, the period between the arrival of the culture in the laboratory to the initial reporting of a positive result was greater than 24 h but less than 48 h, and in 2% of patients (treated as pathogens but likely contaminants) greater than 48 h. The most common organism cultured (in 31% of patients) was Escherichia coli.

CONCLUSIONS

With the present culture technique, most, if not all, clinically significant positive blood and CSF results are reported by 48 h of culture incubation.