Evaluation of hydrogen peroxide-based foam disinfection for reducing gram-negative bacterial contamination in hospital sinks

Abstract Background: Hospital sink drains are recognized reservoirs for gram-negative bacteria (GNB). This study evaluates the efficacy of a sink drain disinfection strategy using hydrogen peroxide-based foam, mechanical cleaning, and drain cover replacement in reducing GNB bioburden in a neonatal intensive care unit (NICU). Methods: We conducted a prospective cohort study of 30 NICU room sinks comparing three interventions: (1) foam disinfection alone ( n = 5), (2) foam with mechanical cleaning ( n = 5), and (3) foam with drain cover replacement ( n = 5), and (4) foam, mechanical cleaning, and drain cover replacement ( n = 5), to controls (no intervention, n = 10). Samples from sink drains, faucets, counters, basins, and drain covers were collected at baseline (Day 0) and post-intervention (Days 1, 3, 5, and 7). Bacterial colony counts were analyzed using linear regression models. Results: At baseline, sink drains and drain covers had the highest bioburden (total GNB mean ln-CFU: 15.4 and 16.4), with Pseudomonas aeruginosa (33%) and Stenotrophomonas maltophilia (39%) as predominant isolates. The intervention combining foam, mechanical cleaning, and drain cover replacement achieved the greatest bioburden reduction on Day 1 in drains (mean ln-CFU reduction = 11.0, 95% CI: 6.4, 16.0, p < 0.001) and covers (mean reduction = 14.0, 95% CI: 8.7, 19.0, p < 0.001), with sustained effects through Day 7. Recolonization to ∼50% of baseline was evident by Day 5 in both sites. Conclusions: Physical bioburden removal improved the effect of a foaming disinfectant in reducing GNB. However, recolonization occurred by day 5.