Microbial biofilms on needleless connectors for central venous catheters: comparison of standard and silver-coated devices collected from patients in an acute care hospital.

Microorganisms may colonize needleless connectors (NCs) on intravascular catheters, forming biofilms and predisposing patients to catheter-associated infection (CAI). Standard and silver-coated NCs were collected from catheterized intensive care unit patients to characterize biofilm formation using culture-dependent and culture-independent methods and to investigate the associations between NC usage and biofilm characteristics. Viable microorganisms were detected by plate counts from 46% of standard NCs and 59% of silver-coated NCs (P=0.11). There were no significant associations (P>0.05, chi-square test) between catheter type, side of catheter placement, number of catheter lumens, site of catheter placement, or NC placement duration and positive NC findings. There was an association (P=0.04, chi-square test) between infusion type and positive findings for standard NCs. Viable microorganisms exhibiting intracellular esterase activity were detected on >90% of both NC types (P=0.751), suggesting that a large percentage of organisms were not culturable using the conditions provided in this study. Amplification of the 16S rRNA gene from selected NCs provided a substantially larger number of operational taxonomic units per NC than did plate counts (26 to 43 versus 1 to 4 operational taxonomic units/NC, respectively), suggesting that culture-dependent methods may substantially underestimate microbial diversity on NCs. NC bacterial communities were clustered by patient and venous access type and may reflect the composition of the patient's local microbiome but also may contain organisms from the health care environment. NCs provide a portal of entry for a wide diversity of opportunistic pathogens to colonize the catheter lumen, forming a biofilm and increasing the potential for CAI, highlighting the importance of catheter maintenance practices to reduce microbial contamination.

Distribution of pathogens in central line-associated bloodstream infections among patients with and without neutropenia following chemotherapy: evidence for a proposed modification to the current surveillance definition.

OBJECTIVE: Many bloodstream infections (BSIs) occurring in patients with febrile neutropenia following cytotoxic chemotherapy are due to translocation of intestinal microbiota. However, these infections meet the National Healthcare Safety Network (NHSN) definition of central line-associated BSIs (CLABSIs). We sought to determine the differences in the microbiology of NHSN-defined CLABSIs in patients with and without neutropenia and, using these data, to propose a modification of the CLABSI definition. DESIGN: Retrospective review. SETTING: Two large university hospitals over 18 months. METHODS: All hospital-acquired BSIs occurring in patients with central venous catheters in place were classified using the NHSN CLABSI definition. Patients with postchemotherapy neutropenia (500 neutrophils/mm(3) or lower) at the time of blood culture were considered neutropenic. Pathogens overrepresented in the neutropenic group were identified to inform development of a modified CLABSI definition. RESULTS: Organisms that were more commonly observed in the neutropenic group compared with the nonneutropenic group included Escherichia coli (22.7% vs 2.5%; P < .001) but not other Enterobacteriaceae, Enterococcus faecium (18.2% vs 6.1%; P = .002), and streptococci (18.2% vs 0%; P < .001). Application of a modified CLABSI definition (removing BSI with enterococci, streptococci, or E. coli) excluded 33 of 66 neutropenic CLABSIs and decreased the CLABSI rate in one study hospital with large transplant and oncology populations from 2.12 to 1.79 cases per 1,000 line-days. CONCLUSIONS: Common gastrointestinal organisms were more common in the neutropenia group, suggesting that many BSIs meeting the NHSN criteria for CLABSI in the setting of neutropenia may represent translocation of gut organisms. These findings support modification of the NHSN CLABSI definition.

Electronic documentation of central venous catheter-days: validation is essential.

BACKGROUND: Measurement of central line-associated bloodstream infection (CLABSI) rates outside of intensive care units is challenged by the difficulty in reliably determining central venous catheter (CVC) use. The National Healthcare Safety Network (NHSN) allows for use of electronic data for determination of CVC-days, but validation of electronic data has not been studied systematically. OBJECTIVE: To design and validate a process to reliably measure CVC-days outside of the intensive care units that leverages electronic documentation. METHODS: Thirty-four inpatient wards at 2 academic hospitals using a common electronic platform for nursing documentation were studied. Electronic queries were created to capture patient and CVC information, and tools and processes for tracking and reporting errors in documentation were developed. Strategies to validate electronic data included comparisons with manual CVC-day determinations and automated data validation using customized tools. Interventions included redesign of documentation interface, real-time audit with feedback of errors, and education. The primary outcome was patient-level total error rate in electronic CVC-day measurement compared with manually counted CVC-days. RESULTS: At baseline, there were a mean (± standard deviation) of [Formula: see text] electronic CVC-day errors (omission and commission errors summed and counted equally) per manually counted CVC-day. After several process improvement cycles over 7 months, the error rate decreased to <0.05 errors per CVC-day and remained at or below this level for 2 years. CONCLUSIONS: Baseline electronic CVC-day counts had a high error rate. Stepwise interventions reduced errors to consistently low levels. Validation of electronic calculation of CVC-days is essential to ensure accuracy, particularly if these data will be used for interinstitutional comparison.