Abstract
<title>Abstract</title> <p>Background Evidence remains limited on how bacterial contamination burden is distributed across sites on long-sleeved nurses’ uniforms and how it changes during cumulative wearing under real-world nursing conditions. This study evaluated site distribution, cumulative wearing-workday changes and high-contamination patterns of bacterial burden on long-sleeved nurses’ uniforms in a respiratory ward. Methods This single-centre repeated-measures observational study included 12 registered nurses in a respiratory ward of a tertiary teaching hospital. Each nurse wore the same hospital-laundered long-sleeved uniform. Samples were collected from seven predefined uniform sites on the 3rd, 5th and 7th cumulative wearing workdays at 10:00 and 16:00, yielding 504 valid sampling points. Total bacterial colony counts were measured by standardized area swabbing and expressed as CFU/100 cm². A linear mixed-effects model (LMM) was used to analyse contamination burden. Results Bacterial growth was detected in 90.9% of sampling points. The median colony count was 80.0 CFU/100 cm², with a right-skewed distribution and extreme high-contamination values. Unadjusted analyses showed significant differences across sampling sites and cumulative wearing workdays. In the mixed-effects model, the 5th and 7th cumulative wearing workdays were associated with higher contamination burden than the 3rd workday, whereas no significant difference was observed between 10:00 and 16:00. Conclusions Long-sleeved nurses’ uniform contamination in a respiratory ward was common and characterized by uneven site distribution, wearing-workday-related changes and a skewed burden pattern. Uniform monitoring should focus on contamination burden, high-contact sites and cumulative wearing stages rather than bacterial detection alone.</p>