P-258. A Longitudinal Study on the Impact of Sink Interventions on Environmental Bioburden and Patient Infections within Two Intensive Care Units at an Academic Hospital

Abstract Background Patient room sinks are frequently identified as potential sources for hospital-associated infections (HAIs), but there are no clear recommendations for interventions to reduce sink-related pathogenic bioburden. We conducted one of the first longitudinal crossover trials to assess the impact of practical sink interventions in an academic hospital.Figure 1.Contamination levels in patient room sink p-trap and tap water between units over time.Black lines represent samples with CFU/mL above the limit of detection. Methods We conducted a 4-phase randomized crossover trial in a medical ICU (MICU) and burn ICU (BICU). Each phase was 8 weeks with a 2-week washout between phases: drain covers, point-of-use filters, both, or no intervention on patient room sinks by unit. Environmental samples from tap water, p-trap water, air, and swabs of the sink basin and adjacent surface were collected every 2 weeks from 5 patient room sinks per unit. Colony-forming units (CFU)/mL of non-tuberculous mycobacteria (NTM), carbapenem-resistant Enterobacterales (CRE), multidrug-resistant Enterobacterales (MDRE), and Stenotrophomonas maltophilia were calculated following MALDI-TOF speciation. Patient HAI results were also recorded. Results Without filters, 68.7% (68/99) of tap water samples were positive, compared to 2.2% (2/90) with filters (p< 0.05). P-trap samples were highly variable with high bioburden and no clear time trends at the room or unit level (Figure 1). Positive air and surface samples rarely occurred but were most common in the drain cover phase (12/135). Within rooms, environmental samples were primarily positive before patient clinical isolates of the same species (7/8). Tap water samples across both units were primarily positive for NTM (71/189) yet no study-room-associated NTM infections were identified. Conclusion We identified that sinks, particularly p-traps, present a consistent source of pathogenic bioburden with fluctuating populations yet rarely contributed to surface/air contamination with organisms of interest in ICU patient rooms. Neither intervention impacted p-trap colonization (CFU/mL). We found that point-of-use filters consistently and effectively removed NTM from tap water. Drain covers were not found to be a useful intervention for reducing surface bioburden. Future research on decolonizing pathogenic bacteria from patient room p-traps is needed. Disclosures Becky A. Smith, MD, UpToDate: royalties