ATP Bioluminescence Feedback Is Associated with Reduced Residual Hand Contamination Among Healthcare Workers: A Single-Center Before-and-After Study

BACKGROUND AND OBJECTIVES: Hand hygiene remains one of the most important measures for preventing healthcare-associated infections, yet its implementation in routine clinical practice remains suboptimal. This study aimed to evaluate whether repeated hand hygiene retraining combined with adenosine triphosphate (ATP) bioluminescence feedback was associated with reduced ATP-assessed residual organic contamination on the hands of healthcare workers in a real-world hospital setting. MATERIALS AND METHODS: We conducted a single-center before-and-after interventional study in 2025 at the County Emergency Hospital of Deva, Romania. Hand contamination was assessed using ATP bioluminescence testing, and results were categorized as low residual contamination (≤20 RLU), intermediate residual contamination (21-59 RLU), or high residual contamination (≥60 RLU). One ATP assessment was performed before and one after a repeated hand hygiene retraining program delivered during 2025. The primary outcomes were the change in mean ATP values and the change in ATP-defined contamination categories between baseline and post-intervention assessment. RESULTS: < 0.01). Improvement was observed across all professional categories. Physicians showed the highest post-intervention proportion of compliant results (85.0%), followed by nurses (61.1%) and auxiliary staff (35.7%). ATP values decreased significantly in all seven departments, with relative reductions ranging from 61.0% to 63.4%. CONCLUSIONS: Repeated hand hygiene retraining combined with ATP bioluminescence feedback was associated with a substantial reduction in ATP-assessed residual hand contamination among healthcare workers in this hospital setting. The intervention was followed by both a marked reduction in ATP values and a favorable shift in ATP-defined contamination categories across departments and professional groups. Because ATP is an indirect and device-dependent marker of residual organic material, these findings should be interpreted cautiously and primarily as evidence of improved ATP-assessed hand cleanliness within the study setting rather than as direct evidence of WHO-defined hand hygiene compliance or microbiological decontamination.