Occurrence and documentation of low-level bacteremia in a community hospital's patient population.

To document the incidence of low-level bacteremia in the patient population of this study, two blood culture sets were collected from symptomatic patients weighing more than 80 pounds. Each blood culture set consisted of a lysis-centrifugation tube and three bottles containing different culture broths, each inoculated with 10 mL blood. Pathogens from 63 (26.4%) and 48 (20.1%) of the 239 culture-positive patients were recovered from only one and two of the eight culture devices, respectively, representing low-level bacteremia. Isolates from another 60 (25.1%) of the 239 patients were recovered from all eight of the culture devices, representing high-level bacteremia. Whether patients had low-level or high-level bacteremia, there were mostly insignificant differences in the types of species recovered, in the percentages of patients for whom therapy was initiated or changed following the laboratory's reports, and in the clinical signs, symptoms, and characteristics of the patients. Clinically documented, low-level bacteremia is relatively common in this community hospital's patient population. Culturing of up to 80 mL of blood was required for detection of all pathogens from patients weighing more than 80 pounds.