Reduction of Environmental Bioburden in Inpatient Rooms Using Activated Hydrogen Peroxide

Reduction of Bioburden in Inpatient Rooms Using Activated Hydrogen Peroxide. 

Andrews BJ, Medvecky ML, Streed SA.  Lee Memorial Health System, Fort Myers, FL.
Background: Lee Memorial Hospital is one of 4 hospitals that form the Lee Memorial Health System in Fort Myers, Florida. The hospital serves as the county’s only Level 2 trauma center and cares for orthopedic, neurology, neurosurgery, and oncology patients. 
The relationship between the environment and the development of healthcare-associated infections is leading Infection Preventionists (IP) to examine traditional room cleaning methods and to explore emerging technologies for more effective room decontamination.   Evidence of intra-facility transmission of A. baumannii led the IP team to assess room decontamination technologies to prevent future recurrences.

Objective: To assess the effectiveness of Activated Hydrogen Peroxide (AHP) mist in the reduction/elimination of residual vegetative microbes  following patient discharge and routine cleaning and to assess the sporicidal effects of AHP when tested against Geobacillus stearothermophilus spores.

Methods: Following patient discharge and before cleaning by Environmental Services (ES), the IP collected baseline quantitative cultures (Phase 1) from eight “high-touch” sites in each of six room using Rodac Plates.  All rooms were then cleaned by ES according to existing protocols and phase two cultures were collected. The room was then fogged with the AHP mist, and a third set of cultures (Phase 3) were obtained. Some flat surfaces in the vicinity of prior sample collection were protected from exposure to the AHP fog and subsequently cultured (Phase 4) after fogging. In addition, Geobacillus stearothermophilus impregnated coupons were positioned various distances from the fogging device and exposed to the AHP fog.

Results: The average number of colony forming units counts per plate (cfu) were as follows:  Phase 1: 28 cfu/plate, Phase 2: 13 cfu/plate, Phase 3: < 1cfu/plate, and Phase 4: 8 cfu/plate.  Statistical analysis showed a significant decrease from Phase 1 to Phase 2, from Phase 2 to Phase 3 and non-significant results from Phase 4 to Phase 2.  All Geobacillus coupons were inactivated after 30 minutes exposure to AHP fog.

Conclusions: Routine cleaning may leave behind residual contamination seen by examining the Phase 2 results.  Subsequent AHP fogging eliminated most residual microbes as can be seen by comparing Phase 2 and Phase 3 results.  The apparent reduction seen in Phase 3 was not due to residual disinfectant agent as evidenced by Phase 4 results.  The complete inactivation of Geobacillus stearothermophilus on test coupons is encouraging relative to problematic spore-forming pathogens.  The goal of this evaluation was to ascertain the effectiveness of the AHP system and these results provide strong evidence of its efficacy and suggest that additional investigation of this technology is warranted.