The CDC states that ultraviolet irradiation of air is an effective means of “reducing the transmission of airborne bacterial and viral infections in hospitals.”1 Ultraviolet germicidal irradiation (UVGI) occurs when UV light at an effective wavelength of 254 nanometers, disrupts the nucleic acid in the DNA of a microorganism, preventing it from replicating.
The development of active UVGI air treatment systems that assume the footprint of a standard 2’ x 4’ ceiling panel or light fixture was developed in recent years. Similar to upper room air treatment and active air duct treatment, these systems can be safely used in occupied spaces 24/7/365 where the pathogens are generated and freely circulated. Below are a few studies that show the effectiveness of this UV-C technology in healthcare.
After installing UV-C ceiling mounted systems, airborne bacteria in patient rooms were reduced an average of 42% in a hospital in Kentucky.2 Common HAIs and catheter-associated urinary tract infections were reduced significantly as were overall infections by 60%. There were no reported changes to the amount or type of cleaning done, infection control protocols, or reporting procedures. Other infections traditionally considered contact transmissible (central line–associated bloodstream infection and methicillin-resistant Staphylococcus aureus), also declined noticeably.
Conclusions: Continuous shielded UV-C reduced airborne bacteria and may also lower the number of HAIs, including those caused by contact pathogens. Reduced infections result in lessened morbidity and lower costs.
Over the course of six months, data was collected and analyzed in a study that was conducted at a long-term care hospital in TN.3 The overall infection rate was significantly lower in rooms with UV-C units than in those without. The bacteria air sampling in the patient rooms were reduced by 51% and the total reduction in infections dropped by 28%. An anecdotal note to this study, staff reported that allergy symptoms were reduced, and absenteeism was lowest in the wing where the UV-C systems were installed.
Conclusion: Findings suggest that continuous exposure to UV-C treated air reduces HAIs. Shielded UV-C units in patient rooms may be an effective non-staff intervention dependent method for reducing HAIs.
PEER-REVIEW PHARMACY STUDY
Viable air particles pose a risk in areas where sterile preparations are compounded.4 Mean airborne fungal and bacterial colony forming units were obtained pre-installation and again in 6 months. A statistically significant decrease of 78% and 62% was observed for fungal and bacterial particles, respectively.
After installing the UV-C systems in the anteroom, dispensing/ receiving and processing areas, bacteria and fungi was decreased in the anteroom by 86% and 90% respectively. The UV-C systems reduced the contaminated air flow, so the levels of bacteria and fungi were decreased by 92% and 100% in the compounding IV room where no units were installed.
Conclusions: This study demonstrates how using shielded UV-C technology can decrease the spread of airborne pathogens throughout a compounding pharmacy.
PEER REVIEW AIR AND SURFACE
Field trials were set up at three hospitals (Texas, Nevada, and Massachusetts) where we tested air and surface for bacteria, installed continuous UV-C products at the room level, and then tested air and surface again.5 In all cases, airborne bacteria was reduced between 79% and 91%over pre-installation values. Most surfaces also showed reductions in bacteria from 48% to 69%, although we report one incident of an increase of 288%.
Conclusions: The data indicate that using active, shielded UV-C air technology at the room level reduces the bioburden in the air and on surfaces, including in occupied spaces.
UV vs. CORONAVIRUSES
There is currently great interest in emerging pathogens like coronaviruses. Approximately 100 sequences of the SARS-CoV-2 genome have been published and these suggest there are two types, Type I and Type II, of which the latter came from the Huanan market in China while the Type I strain came from an unknown location (Zhang 2020).
The effectiveness of UV on Coronaviruses was started by Hirano back in 1978. The table below summarizes the results of studies that have been performed on Coronaviruses under ultraviolet light exposure, with the specific species indicated in each case. The D90 value indicates the ultraviolet dose for 90% inactivation. Although there is a wide range of variation in the D90 values, this is typical of laboratory studies on ultraviolet susceptibility. The range of D90 values for coronaviruses is 7-241 J/m 2, the average which is 67 J/m 2, should adequately represent the ultraviolet susceptibility of the SARS-CoV-2 (COVID-19) virus.
UV ANGEL PERFORMANCE/VALIDATION STUDIES
UV Angel has conducted two separate laboratory tests by an independent third party against surrogate pathogens including Escherichia coli (gram negative), Staphylococcus aureus (gram positive), Cladosporium cladosporioides (fungus spore formers) and MS2 Bacteriophage (MS2) (virus surrogate).6 The UV Angel Air showed elimination rates from 90%. Laboratory tests and mathematical modeling show elimination rates approaching 100% against more than 80 serious disease-causing pathogens.
UV mathematical modeling and D90 rates have been established for 80 pathogens, known or suspected airborne component in their transmission cycle, including bacteria, viruses, and fungi. Many pathogens, if they are drawn into the UVGI chamber, are neutralized in a single pass. Perhaps more significantly, for some of the most virulent pathogens, including MRSA, VRE, and C. difficile, the removal rate (reflecting both filtration and UV disinfection) was 100 percent modeled for those pathogens that pass through the chamber.
Table 4: Combined UV + Filter Removal Rates
Images during lab testing
PROOF OF EFFECTIVENESS
Tests conclusively support that UV Angel Air treats bacteria, fungus and viruses in the air including: Gram negative and gram-positive bacteria, fungal pathogens and viral surrogates.
The UV Angel Air results showed laboratory elimination rates up to 99.99%.
Sources: Centers for Disease Control and Prevention. 2007 Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings. Available from: http://www.cdc.gov/hicpac/2007IP/2007isolationPrecautions.html. Accessed 26 August 2016 2. Tina Ethington, MSN, RN, CEN, NE-BC, Sherry Newsome, BSN, RN, MBA/MNA, Jerri Waugh, BSN, RN, MBA/MHA, Linda D. Lee, DrPH, MBA, Cleaning the air with ultraviolet germicidal irradiation lessened contact infections in a long-term acute care hospital, American Journal of Infection Control, December 2017 3. Douglas W.
Kane, MD; Cynthia Finley RRT; Diane Brown RRT, Linda Lee PhD, UV-C Light and Infection Rate in a Long Term Care Ventilator Unit, May 23, 2016 4. Don Guimera, MSN, RN, CIC, CCRP, FAPIC, Jean Trzil, PharmD, Joy Joyner, RN, CIC, Nicholas D. Hysmith, MD, FAAP, Effectiveness of a shielded UV-C air disinfection system in an inpatient pharmacy of a tertiary care children’s hospital, American Journal of Infection Control, August 2017 5. Linda D. Lee., DrPH, MBA, Surface and air: What impact does UV-C at the room level have on airborne and surface bacteria? Canadian Journal of Infection Control, Summer 2017 6. Lee. Report on the Performance of the UV Angel Air aWalker CM, Ko G Effect of ultraviolet germicidal irradiation on viral aerosols. Environ. Sci. Technol. 2007, 41, 15, 5460-5465 Weiss M, Horzinek MC. Resistance of Berne virus to physical and chemical treatment. Vet Microbiol.
1986;11(1-2):41-49. doi:10.1016/0378-1135(86)90005-2 Hirano N, Hino S, Fujiwara K Physico-chemical properties of mouse hepatitis virus (MHV-2) grown on DBT cell culture. Microbiol Immunol. 1978;22(7):377-90. bSaknimit M1, Inatsuki I, Sugiyama Y, Yagami K. Virucidal efficacy of physico-chemical treatments against coronaviruses and parvoviruses of laboratory animals. Jikken Dobutsu. 1988 Jul;37(3):341-5. cDuan SM, et. al, Stability of SARS coronavirus in human specimens and environment and its sensitivity to heating and UV irradiation. Biomed Environ Sci. 2003 Sep;16(3):246-55. Darnell ME, et.
al, Inactivation of the coronavirus that induces severe acute respiratory syndrome, SARS-CoV. J Virol Methods. 2004 Oct;121(1):85-91. dKariwa H1, Fujii N, Takashima I Inactivation of SARS coronavirus by means of povidone-iodine, physical conditions, and chemical reagents. Jpn J Vet Res. 2004 Nov;52(3):105-12.
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