Open-but-unused wound dressings showed detectable microbial contamination from the initial sampling day following opening when stored under routine clinical conditions, according to a study published in the International Wound Journal.
In this observational, descriptive, longitudinal study, researchers evaluated 11 non-adhesive wound dressings stored and handled under usual clinical conditions in hospital and primary care settings in Spain.
Overall, microbial growth was detected in 185 of 286 samples (65%) during the culture process. Among samples collected over multiple time points up to 6 days following opening, 34% of direct cultures showed microbial growth exceeding the predefined threshold. After enrichment culture, 95% of samples were positive, indicating widespread low-level contamination.
Contamination was detectable from the initial sampling day and increased with storage time and repeated handling.
“Open-but-unused portions of wound dressings were frequently found to harbour detectable microbial contamination, particularly after enrichment culture,” wrote lead study researcher Andoni Carrión Jiménez, of the Institute of Research and Innovation in Biomedical Sciences of the Province of Cadiz, and colleagues.
Coagulase-negative staphylococci were identified in 77% of contaminated samples, followed by Staphylococcus aureus in 17%. Gram-negative organisms, including Escherichia coli and Pseudomonas species, were detected less frequently.
Contamination rates were higher in hospital samples than in primary care samples (72% vs 57%), with Staphylococcus aureus also more frequently detected in the hospital setting (27% vs 4%).
Silver-containing dressings showed slightly lower contamination rates than non-silver dressings, but differences were not statistically significant. Additionally, scissors used to cut dressings showed contamination in 75% of samples, with similar microorganisms identified on scissors and dressings, suggesting a potential role in cross-contamination.
The study was conducted under routine clinical conditions without standardized storage or handling protocols, with repeated sampling from the same opened dressing packs over time.
Limitations included the observational design, lack of standardized environmental controls, and sampling from a single hospital unit and primary care center.
The findings indicate that microbial contamination of open-but-unused wound dressings occurs early under routine handling conditions across clinical settings and dressing types. The study did not assess whether this contamination leads to clinical infection.
The researchers reported no conflicts of interest.
Source: International Wound Journal
