Sink and Drain Monitoring and Decontamination Protocol for Carbapenemase-producing Enterobacteriaceae (CPE)

Background Carbapenemase-producing Enterobacteriaceae (CPE) can colonize hospital drains and spread from drain to patient. The optimal approach to preventing drain colonization is unknown. We present our hospital's experience with a drain decontamination protocol. Methods Our facility is a 450 bed academic hospital in Toronto. Between 2017 and 2019, we identified 32 CPE positive inpatients 24 of whom were known to carry CPE or were CPE screen positive on admission. We implemented a sink drain protocol to prevent plumbing colonization. CPE patients admitted >48 hours have all drains in their room disinfected weekly and when transferred or discharged. Hydrogen peroxide gel (4.5%) is poured into the drain and flushed after 10 minutes. Drain swabs are collected >48 after disinfection; some rooms were also tested pre-disinfection. If post-disinfection swabs were positive, enhanced disinfection methods were used. Results 4.7% (18/387) sink/drain swabs were CPE positive. Eight positive swabs were collected before and ten after disinfection. These 18 positive swabs were from drains in 8 patient rooms and 2 communal showers. Enterobacter species predominated (5/10) and CPE enzymes included KPC(4), NDM(3), OXA-48(2), and mixed NDM&KPC(1). Positive room drains matched the patient's CPE enzyme for 7 of 8 positive rooms. Drain disinfection was successful for 70% (7/10) of positive sinks/drains. Three drains failed disinfection and required the enhanced disinfection protocol. After successful disinfection, all room drains have remained negative on at least one additional swab performed >1 month after successful disinfection but two communal shower drains reverted to positive with the same CPE enzyme on retesting >6 months post-disinfection. Conclusions Sink drains can become contaminated with CPE. Our disinfection protocol was largely successful in eradicating CPE from drains, although two communal shower drains reverted to positive. Disinfection of drains in CPE rooms routinely and at discharge may prevent drain colonization and reduce CPE transmission risk.