Do plexiglass barriers reduce the risk for transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)?

Barriers are commonly installed in workplace situations where physical distancing cannot be maintained, but their effectiveness in decreasing viral transmission is unknown. In simulations, physical barriers with no openings were effective in reducing contamination with an aerosolized benign virus or fluorescent microspheres, but barriers with openings were not.

Effectiveness of a novel 1-step cleaner and disinfectant against Candida auris.

A novel 1-step anionic surfactant disinfectant was effective against Candida auris isolates from the 4 major phylogenetic clades as well as methicillin-resistant Staphylococcus aureus (MRSA) and the enveloped virus bacteriophage Phi6. This anionic surfactant disinfectant may be a useful addition to the disinfectant products available for use against C. auris.

Effectiveness of commercial portable air cleaners and a do-it-yourself minimum efficiency reporting value (MERV)-13 filter box fan air cleaner in reducing aerosolized bacteriophage MS2.

In an unventilated room, 2 commercial portable air cleaners with high efficiency particulate air (HEPA) filters and a do-it-yourself box fan air cleaner with minimum efficiency reporting value (MERV)-13 filters significantly reduced aerosolized bacteriophage MS2. Increasing airflow and addition of ultraviolet-C light plus titanium dioxide-generated photocatalytic oxidation enhanced viral clearance.

Real-World Evidence on the Effectiveness of Plexiglass Barriers in Reducing Aerosol Exposure.

Reprinted with permission, Cleveland Clinic Foundation ©2022. All Rights Reserved. Background: Barriers are commonly installed in workplace situations where physical distancing cannot be maintained to reduce the risk for transmission of respiratory viruses. Although some types of barriers have been shown to reduce exposure to aerosols in laboratory-based testing, limited information is available on the efficacy of barriers in real-world settings. Methods: In an acute care hospital, we tested the effectiveness of in-use plexiglass barriers in reducing exposure of staff to aerosolized particles. A nebulizer was used to release 5% NaCl aerosol 1 meter from staff members with and without the barrier positioned between the point of aerosol release and the hospital staff. Particle counts on the staff side of the barrier were measured using a 6-channel particle counter. A condensed moisture (fog) generating device was used to visualize the airflow patterns. Results: Of 13 in-use barriers tested, 6 (46%) significantly reduced aerosol particle counts detected behind the barrier, 6 (46%) reduced particle counts to a modest, non-significant degree, and 1 (8%) significantly increased particle counts behind the barrier. Condensed moisture fog accumulated in the area where staff were seated behind the barrier that increased particle exposure, but not behind the other barriers. After repositioning the ineffective barrier, the condensed moisture fog no longer accumulated behind the barrier and aerosol exposure was reduced. Conclusion: In real-world settings, plexiglass barriers vary widely in effectiveness in reducing staff exposure to aerosols, and some barriers may increase risk for exposure if not positioned correctly. Devices that visualize airflow patterns may be useful as simple tools to assess barriers.

Airflow patterns in double occupancy patient rooms may contribute to roommate-to-roommate transmission of severe acute respiratory syndrome coronavirus 2.

BACKGROUND: Hospitalized patients are at risk to acquire severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from roommates with unrecognized coronavirus disease 2019 (COVID-19). We hypothesized that airflow patterns might contribute to SARS-CoV-2 transmission in double occupancy patient rooms. METHODS: A device emitting condensed moisture was used to identify airflow patterns in double occupancy patient rooms. Simulations were conducted to assess transfer of fluorescent microspheres, 5% sodium chloride aerosol, and aerosolized bacteriophage MS2 between patient beds 3 meters apart and to assess the effectiveness of privacy curtains and portable air cleaners in reducing transfer. RESULTS: Air flowed from inlet vents in the center of the room to an outlet vent near the door, resulting in air currents flowing toward the bed adjacent to the outlet vent. Fluorescent microspheres (212-250 µm diameter), 5% sodium chloride aerosol, and aerosolized bacteriophage MS2 released from the inner bed were carried on air currents toward the bed adjacent to the outlet vent. Closing curtains between the patient beds reduced transfer of each of the particles. Operation of a portable air cleaner reduced aerosol transfer to the bed adjacent to the outlet vent but did not offer a benefit over closing the curtains alone, and in some situations resulted in an increase in aerosol exposure. CONCLUSION: Airflow patterns in double occupancy patient rooms may contribute to risk for transmission of SARS-CoV-2 between roommates. Keeping curtains closed between beds may be beneficial in reducing risk.

Use of carbon dioxide measurements to assess ventilation in an acute care hospital.

Poorly ventilated indoor spaces pose a risk for airborne transmission of SARS-CoV-2. We measured carbon dioxide levels in a multiple areas in an acute care hospital to assess the adequacy of ventilation. Carbon dioxide levels remained below 800 parts per million in most areas but exceeded this level in a small conference room with 8 occupants, an office with 3 occupants, and a bathroom with 2 occupants. Measuring carbon dioxide levels could provide a simple means for healthcare facilities to assess the adequacy of ventilation.

Evaluation of 2 Ultraviolet-C Light Boxes for Decontamination of N95 Respirators.

BACKGROUND: Ultraviolet-C (UV-C) light devices are effective in reducing contamination on N95 filtering facepiece respirators. However, limited information is available on whether UV-C devices meet the Food and Drug Administration's (FDA) microbiological requirements for Emergency Use Authorization (EUA) for respirator bioburden reduction. METHODS: We tested the ability of 2 UV-C light boxes to achieve the 3-log10 microorganism reductions required for EUA for reuse by single users. Whole 3M 1860 or Moldex 1513 respirators were inoculated on the exterior facepiece, interior facepiece, and internal fibers with bacteriophage MS2 and/or 4 strains of bacteria and treated with UV-C cycles of 1 or 20 minutes. Colorimetric indicators were used to assess penetration of UV-C through the respirators. RESULTS: For 1 UV-C box, a 20-minute treatment achieved the required bioburden reduction for Moldex 1513 but not 3M 1860 respirators. For the second UV-C box, a 1-minute treatment achieved the required bioburden reduction in 4 bacterial strains for the Moldex 1513 respirator. Colorimetric indicators demonstrated penetration of UV-C through all layers of the Moldex 1513 respirator but not the 3M 1860 respirator. CONCLUSIONS: Our findings demonstrate that UV-C box technologies can achieve bioburden reductions required by the FDA for EUA for single users but highlight the potential for variable efficacy for different types of respirators.

Evaluation of an electrostatic spray disinfectant technology for rapid decontamination of portable equipment and large open areas in the era of SARS-CoV-2.

In the setting of the coronavirus disease 2019 pandemic, efficient methods are needed to decontaminate shared portable devices and large open areas such as waiting rooms. We found that wheelchairs, portable equipment, and waiting room chairs were frequently contaminated with potential pathogens. After minimal manual precleaning of areas with visible soiling, application of a dilute sodium hypochlorite disinfectant using an electrostatic sprayer provided rapid and effective decontamination and eliminated the benign virus bacteriophage MS2 from inoculated surfaces.