Comparison of Two Novel Methods for Sink Drain Disinfection

Abstract

Background: Sink drainage systems are a potential reservoir for the dissemination of gram-negative bacilli but are not amenable to standard methods of cleaning and disinfection. Pouring liquid disinfectants down drains has only a limited and transient effect on drain colonization, presumably due to inadequate disinfectant contact time and suboptimal penetration into areas harboring biofilm-associated organisms. Methods: We compared the antimicrobial efficacy of 2 novel sink disinfection methods intended to enhance disinfectant contact time and penetration. Healthcare facility sinks were randomly assigned to disinfection with 300 mL hydrogen peroxide-based disinfectant applied either as a foam (N = 13 sinks) or instilled for 30 minutes behind a temporary obstruction created by an inflated urinary catheter balloon (N = 12 sinks). Swabs were used to collect quantitative cultures from the proximal sink drain to depth of 2.5 cm (1 inch) below the strainer before treatment and at 15 minutes and 1, 2, 3, 5, and 7 days after treatment. Repeated measures analysis of variance was performed to compare the efficacy of the 2 treatments. Results: As shown in Fig. 1, both methods yielded an initial reduction of >3 log10 CFU of gram-negative bacilli. Over the 7-day follow-up period, disinfectant instillation resulted in significantly greater reduction than the foam application (P < .01). Recovery of sink colonization to >2 log per swab occurred at day 3 for both treatments, whereas recovery to >3 log per swab occurred on day 3 for the foam treatment versus day 7 for disinfectant instillation. Conclusions: Two novel disinfection methods were effective in reducing sink drain colonization for several days. The instillation method was more effective than the foam method in maintaining reductions over 7 days.Funding: NoneDisclosures: NoneDisclosures: NoneFunding: None