Candida auris (C. auris) is an emerging multidrug-resistant fungus that is a growing concern for healthcare facilities worldwide. According to the Centers for Disease Control and Prevention (CDC), clinical cases of C. auris in the United States have increased dramatically in recent years, rising from just 51 reported cases in 2016 to more than 6,300 clinical cases by 2024. The CDC has classified C. auris as an “urgent antimicrobial resistance threat” because it can spread rapidly in healthcare environments, persist on environmental surfaces, and is often resistant to many antifungal drugs. Recent outbreaks have been reported across multiple states, including significant activity in the western U.S., highlighting the growing importance of effective environmental disinfection strategies in healthcare facilities.
Because C. auris can persist on surfaces for weeks and spread through contaminated healthcare environments, infection prevention teams are increasingly evaluating automated whole-room disinfection technologies to supplement manual cleaning.
To better understand the effectiveness of aerosolized hydrogen peroxide (aHP) against C. auris, Breezy Med conducted preclinical fogging efficacy testing in a controlled environmental chamber using the Breezy Blue® aHP system with HaloSpray disinfectant.
This testing represents the first step in a broader clinical research program designed to evaluate whether whole-room aHP disinfection can help reduce healthcare-associated infections (HAIs) in real hospital settings.
Testing was conducted in a sealed environmental chamber with a volume of 140 m³ (4,944 ft³). The chamber was configured to simulate a large patient-care environment while allowing precise environmental monitoring. The Breezy Blue system was positioned in the far right corner of the chamber and operated remotely from outside the sealed room.
Located throughout the chamber at floor, mid-height, tabletop, and ceiling positions
Environmental monitoring sensors were placed near most sampling locations to measure hydrogen peroxide concentration, humidity, and temperature throughout the test. The chamber itself was fully sealed, including taped doors, to ensure controlled conditions during the disinfection cycle.
Figure 1. Breezy Blue positioned in the corner of the environmental chamber used for Candida auris fogging efficacy testing.
Total treatment duration: 30 minutes
After the treatment cycle, the room remained sealed for several additional minutes as the high-efficiency HEPA filtration units were activated to accelerate aeration. Researchers then waited until hydrogen peroxide levels fell below 5 ppm before entering the chamber to collect samples. Collected carriers were immediately placed into a hydrogen peroxide neutralization bath before being transferred to growth medium and incubated for up to four days.
The chamber began at approximately 70°F and 24% relative humidity. During the fogging cycle, humidity rapidly increased to approximately 100% relative humidity, demonstrating the rapid saturation of the environment during aerosolized hydrogen peroxide distribution. Temperature briefly dropped several degrees during the fogging phase and gradually returned to baseline as the room aerated.
These conditions are consistent with the physical behavior expected during whole-room aHP disinfection, where the aerosolized droplets distribute throughout the environment and deposit onto exposed surfaces.
Figure 2. Temperature and relative humidity measured in the environmental chamber during the Breezy aHP fogging cycle, illustrating the rapid increase in humidity during disinfectant distribution.
Testing used the Candida auris CDC AR Bank strain #0381, a well-characterized strain used in antimicrobial resistance research. Carriers were inoculated with high concentrations of the organism to create a rigorous challenge.
Results showed consistent reductions across all seven sampling locations, including floor, tabletop, wall, and ceiling positions throughout the chamber. Across the 21 carriers tested, log₁₀ reductions ranged from 3.69 to 4.24, corresponding to 99.98%–99.99% reduction compared to untreated controls. This level of reduction was observed across all seven locations throughout the chamber, including ceiling and floor positions.
Locations further away from the device showed slightly lower reductions, though still within the ~4-log range.
Importantly, the testing environment was a relatively large space—nearly 5,000 ft³—with samples distributed throughout the chamber. The aerosolized disinfectant therefore had to disperse across the entire volume rather than relying on direct line-of-sight exposure to surfaces. The nearly 5,000 ft³ chamber represents a volume comparable to a large patient room or small clinical space.
Figure 3. Hydrogen peroxide concentration measured at multiple locations in the environmental chamber during the Breezy aHP disinfection cycle, demonstrating distribution of the aerosolized disinfectant throughout the full test volume and its decay over time.
Frequent association with healthcare outbreaks
Automated operation enabling standardized, repeatable disinfection
The preclinical results from this environmental chamber study suggest that Breezy’s aHP system can achieve strong reductions of C. auris across a large enclosed space. There results further suggest that aerosolized hydrogen peroxide may play an important role in Candida auris environmental disinfection within healthcare facilities.
While laboratory testing helps demonstrate disinfection efficacy under controlled conditions, the most important question for healthcare facilities is whether improved environmental disinfection can translate into better patient outcomes. Breezy Med is therefore preparing a multi-site clinical study within hospitals to evaluate the impact of Breezy Blue on healthcare-associated infection (HAI) outcomes.
Because C. auris cannot be intentionally introduced into clinical environments for testing, the hospital study will focus on real-world infection outcomes associated with enhanced environmental disinfection. Hospitals participating in the study will use Breezy Blue as part of their environmental disinfection protocols while researchers evaluate trends in infection rates.
Breezy Med is currently seeking hospitals interested in serving as clinical study sites as well as infection preventionists interested in participating as study collaborators or co-authors.
Participation will provide an opportunity to help generate real-world evidence on automated whole-room disinfection technologies while contributing to peer-reviewed research on infection prevention. Healthcare organizations interested in participating in the study are encouraged to contact Breezy Med for additional details.