Fluorescent tagging for assessment of environmental cleaning in an equine hospital

Background Healthcare-associated infections increase morbidity, mortality, and treatment costs in both human and veterinary medicine, and environmental contamination can contribute to their occurrence. Monitoring of environmental cleaning is an important component of multimodal infection control strategies. Fluorescent tagging is a low-cost, practical approach that correlates with reduced environmental contamination in human and small animal hospitals. Its applicability in equine hospitals, where surface characteristics and contamination risks differ, has not yet been evaluated. Objectives To evaluate fluorescent tagging as a monitoring tool for environmental cleaning in an equine hospital, to assess the impact of active feedback, and to validate an objective ImageJ-based assessment against subjective evaluation. Study Design Before-after study. Methods A commercial fluorescent dye was applied to surfaces in examination rooms and stalls. Fluorescent tag removal was evaluated visually and objectively using standardised photography and ImageJ-based green intensity analysis. Surfaces were sampled repeatedly across two study phases, separated by structured feedback to cleaning staff. Aerobic colony counts (ACC) were performed during phase II adjacent to fluorescent tags to assess bacterial contamination before and after cleaning. Results Objective ImageJ-based analysis accurately distinguished between removed, partially removed, and not removed fluorescent tags, and there was strong agreement with subjective visual assessment. In examination rooms, provision of feedback resulted in a significant overall improvement in cleaning efficacy, particularly in orthopaedic treatment rooms (room1: log-odds ratio = 1.71; q-value = 0.033, room2: log-odds ratio = 2.11; q-value = 0.01), whereas no improvement was observed in stables (q-value >0.05). The ACC were not associated with fluorescent tag removal grades (q-value >0.05). Main Limitations Subjective and objective assessments were performed by the same non-blinded examiner, single centre design and limited ACC assessment. Conclusions Fluorescent tagging is a feasible monitoring method for assessing environmental cleaning efficacy in an equine hospital, and objective quantification correlated closely with subjective visual assessment. Active feedback improved cleaning performance in examination rooms but not in stables.