Microbial Contamination of Open-But-Unused Portions of Wound Dressings in Healthcare Facilities.

To assess the potential for microbial contamination of open-but-unused portions of wound dressings stored under real-life conditions in healthcare facilities, to inform safer and evidence-based wound care practices. Observational, descriptive, longitudinal, prospective study. Eleven types of non-adhesive wound dressings were sampled after opening and storage under usual clinical conditions in a hospital inpatient unit and a primary care centre in Andalusia, Spain. Samples were collected on six predefined sampling days (Days 0, 2, 3, 4, 5 and 6 after opening), cultured under standardised laboratory conditions and microorganisms were identified using mass spectrometry. Differences in contamination were examined by dressing type, healthcare setting, storage time and handling conditions. Microbial growth was frequently detected in open-but-unused dressings from the first day after opening, particularly after enrichment culture and increased with handling and time. The most frequent microorganisms were coagulase-negative staphylococci and Staphylococcus aureus. Contamination patterns were similar across settings, although microbial diversity was higher in the hospital. Silver-containing dressings showed slightly lower contamination, but not enough to indicate protection. Scissors used for cutting dressings had high microbial loads, suggesting a potential source of cross-contamination. Open-but-unused dressings may become contaminated shortly after opening under routine clinical practice conditions, across different healthcare settings and dressing types.