Continuous Photohydrolysis Disinfection Cuts MDROs, COVID-19, and Hospital Transfers in Long-Term Care, Study Finds

Antimicrobial resistance remains a persistent and escalating challenge across health care settings, particularly in long-term care (LTC) facilities where patients are at heightened risk for infection.

A recent case-control experimental study evaluated whether advanced photohydrolysis (AP) continuous disinfection technology could reduce environmental bioburden and improve patient and facility outcomes without increasing reliance on human resources.

The study examined the impact of AP technology on surface, floor, and airborne microbial contamination, as well as multidrug-resistant organism (MDRO) acquisition rates, patient and staff COVID-19 cases, and hospital transfers. Environmental sampling occurred between January 2023 and April 2023, with extended clinical outcome monitoring through July 2023.

“The most powerful infection-prevention tools are the ones that don’t rely on perfect human behavior,” said Deborah L. Birx, MD, chief medical and scientific advisor for ActivePure Medical. “Facilities that embrace 21^st century solutions to continuously and pragmatically reduce contamination in the environment are changing the baseline conditions that allow outbreaks to ignite and spread. Reducing acquired infections is about more than quality metrics. It can mean fewer disruptive hospital stays, less antibiotic exposure, and more days that residents can simply enjoy their lives.”

Study Design and Methods

Two skilled nursing facilities served as intervention centers, with matched regional facilities serving as controls. Baseline environmental samples were collected in January 2023, followed by post-activation sampling every 4 weeks for 3 months. All samples were collected on Wednesday mornings prior to daily environmental services cleaning and shift changes.

The AP technology was installed within the heating, ventilation, and air conditioning system and uses a 253.8 nm UV-C bulb enclosed by a patented photocatalyst to generate trace amounts of oxidative molecules from ambient humidity and effectively initiate photolysis. The authors explain that these molecules continuously neutralize pathogens in the air and on surfaces “to render a consistently clean environment that correlates with lower risk of infection.” without additional staff intervention.

Environmental sampling targeted CDC–defined high-touch surfaces, floors, and corresponding air locations. Surface and floor samples were collected using standardized sponge swabs over a 10 cm × 10 cm area, while air samples were collected using a SAS 180 microbial sampler with 1,000 L of air per sample.

Due to protocol noncompliance, data from 1 intervention site were excluded. Final analysis focused on a single intervention facility compared with two matched controls.

Environmental Outcomes

The study demonstrated statistically significant reductions in microbial contamination following AP technology activation.

For surfaces, mean colony-forming units (CFUs) were reduced from baseline to post-activation month 3 by:

• 93% for aerobic bacteria (P < 0.001)
• 99% for fungi (P < 0.001)
• 99% for MRSA (P = 0.007)

Floor samples showed similarly significant reductions:

• 92% for aerobic bacteria (P = 0.008)
• 96% for fungi (P = 0.01)
• 99% for MRSA (P = 0.006)

Airborne microbial sampling revealed a statistically significant reduction in median aerobic bacterial CFUs, decreasing from 35.5 to 9.5 (P = 0.005). While median airborne fungal CFUs decreased from 6 to 8, this change did not reach statistical significance. The authors noted that these findings highlight how persistent environmental contamination remains a challenge to infection prevention despite routine cleaning, stating that “even correctly performed cleaning, due to its intermittent nature, is inadequate in environments where the contamination is continuous.”

MDRO and COVID-19 Outcomes

Beyond environmental contamination, the study evaluated clinical outcomes over extended observation periods. At the intervention center, MDRO acquisition rates per 1,000 patient days decreased 14% year over year, from 0.29 to 0.25, while control centers experienced a 150% increase, from 0.20 to 0.50. Patient COVID-19 cases showed a substantial reduction. Between February and July 2023, the intervention facility observed a 94% year-over-year reduction, from 10.25 to 0.64 cases per 1,000 patient days. In contrast, control centers experienced a 48% increase, from 9.55 to 14.09.

Staff COVID-19 cases also declined more sharply at the intervention site, with a 79% reduction, from 19 to 4 cases, compared with a 47% reduction at control centers. Additionally, unplanned hospital transfers decreased by 20% at the intervention facility, from 91 to 73, whereas control facilities experienced a 3.5% increase, from 116 to 120.

Discussion and Implications

The study authors emphasized that the measured reductions in environmental bioburden coincided with meaningful improvements observed in patient and facility outcomes. They noted that “these findings of simultaneous reductions in environmental bioburden and pathogen acquisition demonstrate the positive impact that significant and continuous microbial reductions in the environment of care can have on patient outcomes.”

Indeed, “substantial microbial contamination continues to exist on surfaces, floors, and in air despite dedicated cleaning and disinfection efforts,” the authors wrote.

The reduction in patient COVID-19 cases was particularly notable given that the study period overlapped with the 2023 winter surge. The authors stated that these findings support the growing recognition of airborne transmission and the need to address indoor air quality as part of infection prevention strategies.

They further highlighted the operational implications for LTC facilities, noting that reductions in MDRO acquisitions and personal protective equipment use could lower operational costs, especially given estimates that MDRO-related care increases daily costs by $12.45 per patient per day.

“Long-term care facilities are managing both staffing constraints and rising antimicrobial resistance,” Amy Carenza, the chief commercial officer of ActivePure Medical. “In this study, layering in ActivePure’s disinfection technology demonstrated significant bioburden reductions across surfaces, floors, and air after traditional disinfection approaches had plateaued. This technology requires no additional staffing or changes to operational procedures, making it a practical and scalable solution that quickly pays for itself through reduced pathogen transmission and the associated downstream escalations of care.”

Limitations

The authors acknowledged limitations, including reliance on baseline environmental sampling and evaluation of a single MDRO species. The study was not designed to statistically link reductions in environmental contamination to reductions in infections, though the concurrent trends were described as clinically significant.

Conclusion

This study demonstrates that advanced photohydrolysis continuous disinfection technology can significantly reduce environmental microbial contamination and coincide with improvedpatient and staff outcomes in LTC settings. By addressing continuous contamination in air and on surfaces without additional staffing demands, the technology offers a promising addition to existing infection prevention efforts across health care environments.