In vitro survival of skin flora in heparin locks and needleless valve infusion devices.
OBJECTIVE: To determine the extent to which two types of infusion devices, the heparin lock and a needleless valve device, allowed the persistence of inoculated microorganisms. DESIGN: Experiment. SETTING: Clinical microbiology laboratory. OUTCOME MEASURES: Bacterial counts in infusion devices. INTERVENTION: Five of each type of device were inoculated with approximately 10(5) colony-forming units of a strain of Staphylococcus epidermidis and Enterobacter aerogenes and tested for growth at seven time intervals, from 10 minutes to 72 hours after inoculation. RESULTS: Both strains of bacteria were present in each device at every time interval tested, including 72 hours after inoculation. CONCLUSIONS: Bacteria introduced into a heparin lock or valve device may be isolated for prolonged periods of time. This suggests that if such devices are contaminated during use, they may be a potential source of infection. The risk of infection should be one major consideration in risk and benefit deliberations when choosing new products.