Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 Among Residents and Employees in a Veterans Affairs Community Living Center: A 42-Month Prospective Cohort Study.

Background: Understanding routes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission in long-term care facilities is essential for the development of effective control measures. Methods: Between March 1, 2020, and August 31, 2023, we identified coronavirus disease 2019 (COVID-19) cases among residents and employees in a Veterans Affairs community living center that conducted routine screening for asymptomatic COVID-19. Contact tracing was conducted to identify suspected transmission events, and whole genome sequencing was performed to determine the relatedness of SARS-CoV-2 samples. Results: During the 42-month study period, 269 cases of COVID-19 were diagnosed, including 199 employees and 70 residents. A total of 48 (24.1%) employees and 30 (42.9%) residents were asymptomatic. Sequencing analysis provided support for multiple events in which employees transmitted SARS-CoV-2 to co-workers and residents. There was 1 episode of likely transmission of SARS-CoV-2 from one resident to another resident, but no documented transmissions from residents to employees. Conclusions: Transmission of SARS-CoV-2 in the community living center predominantly involved transmission from employees to co-workers and residents. There is a need for improved measures to prevent transmission of SARS-CoV-2 by healthcare personnel.

Evaluation of an Automated Wall-mounted Far Ultraviolet-C Light Technology for Continuous or Intermittent Decontamination of Candida auris on Surfaces.

Background: Technologies that provides safe and effective decontamination of surfaces and equipment between episodes of manual cleaning could be an important advance in efforts to prevent transmission of the emerging fungal pathogen Candida auris. Methods: We tested the efficacy of a novel wall-mounted far ultraviolet-C (UV-C) light technology that delivers far UV-C, when people are not detected within the field of illumination, against C. auris isolates from clades I, II, III, and IV using a quantitative disk carrier test method. In an equipment room, we examined the efficacy of the technology in reducing an isolate of C. auris from clade IV inoculated on multiple sites on portable devices. Results: The far UV-C technology reduced isolates from all 4 clades of C. auris by >3 log10 colony-forming units (CFU) aſter an 8-hour exposure on steel disks. For the clade IV isolate, similar reductions were achieved on glass and plastic carriers. In the equipment room, the technology reduced C. auris inoculated on multiple sites on portable equipment by >2 log10 CFU in 4 hours. Conclusions: The far UV-C technology could be useful for decontamination of surfaces and equipment between episodes of manual cleaning. Additional studies are needed to evaluate the use of the technology in clinical settings.

Efficacy of 23 commonly used liquid disinfectants against Candida auris isolates from the 4 major clades.

We tested the effectiveness of 23 disinfectants used in healthcare facilities against isolates from the 4 major clades of Candida auris. Sporicidal disinfectants were consistently effective, whereas quaternary-ammonium disinfectants had limited activity. Quaternary-ammonium-alcohol and hydrogen-peroxide-based disinfectants varied in effectiveness against C. auris.

Efficacy of a far-ultraviolet-C light technology for continuous decontamination of air and surfaces.

A wall-mounted, far-ultraviolet-C light technology reduced aerosolized bacteriophage MS2 by >3 log10 plaque-forming units within 30 minutes. Vegetative bacterial pathogens on steel disk carriers in the center of the room were reduced by >3 log10 after 45 minutes of exposure, but Candida auris and Clostridioides difficile spores were not.

Inactivation and/or physical removal of Candida auris from floors by detergent cleaner, disinfectants, microfiber, and ultraviolet C light (UV-C).

Contaminated surfaces may be a source of transmission for the globally emerging pathogen, Candida auris. Because floors may be a source of C. auris contamination on hands, strategies for inactivating or removing C. auris from floors were investigated. A sporicidal disinfectant and UV-C were most effective in inactivating C. auris on floors.

Evaluation of a mobile disinfection cabinet using ultraviolet-C light and aerosolized hydrogen peroxide for disinfection of medical equipment.

In laboratory testing, a mobile enclosed disinfection cabinet using ultraviolet-C light and aerosolized hydrogen peroxide was effective for disinfection of hard and soft surfaces. The addition of aerosolized hydrogen peroxide to ultraviolet-C light resulted in improved disinfection of soft surfaces and Clostridioides difficile spores.

A do-it-yourself test protocol using commercial Bacillus atrophaeus spores to evaluate the effectiveness of ultraviolet-C light room-decontamination devices.

We developed a do-it-yourself test protocol using commercial Bacillus atrophaeus spores to assess the efficacy of ultraviolet-C (UV-C) light room-decontamination devices. Overall, 4 UV-C devices reduced B. atrophaeus by ≥3 log10 colony-forming units in 10 minutes, whereas a smaller device required 60 minutes. Of 10 in-use devices, only 1 was ineffective.

Natural History of Clostridioides difficile Colonization and Infection Following New Acquisition of Carriage in Healthcare Settings: A Prospective Cohort Study.

BACKGROUND: Limited information is available on the natural history of Clostridioides difficile colonization and infection in patients with new acquisition of C. difficile in healthcare settings. METHODS: In 3 hospitals and affiliated long-term care facilities, we collected serial perirectal cultures from patients with no diarrhea on enrollment to identify new acquisition of toxigenic C. difficile carriage and determined the duration and burden of carriage. Asymptomatic carriage was defined as transient if only 1 culture was positive, with negative cultures before and after, or persistent if 2 or more cultures were positive. Clearance of carriage was defined as 2 consecutive negative perirectal cultures. RESULTS: Of 1432 patients with negative initial cultures and at least 1 follow-up culture, 39 (2.7%) developed C. difficile infection (CDI) without prior detection of carriage and 142 (9.9%) acquired asymptomatic carriage, with 19 (13.4%) subsequently diagnosed with CDI. Of 82 patients analyzed for persistence of carriage, 50 (61.0%) had transient carriage and 32 (39.0%) had persistent carriage, with an estimated median of 77 days to clearance of colonization (range, 14-133 days). Most persistent carriers had a relatively high burden of carriage and maintained the same ribotype over time, whereas most transient carriers had a low burden of carriage detected only using broth enrichment cultures. CONCLUSIONS: In 3 healthcare facilities, 9.9% of patients acquired asymptomatic carriage of toxigenic C. difficile, and 13.4% were subsequently diagnosed with CDI. Most carriers had transient rather than persistent carriage and most patients developing CDI did not have prior detection of carriage.

Transfer of methicillin-resistant Staphylococcus aureus by fist bump versus elbow bump.

For 40 patients with methicillin-resistant Staphylococcus aureus (MRSA) colonization, fist bump and elbow bump greetings resulted in frequent transfer of MRSA (25% vs 15%, respectively), but significantly fewer colonies were transferred via the elbow bump. Noncontact greetings should be encouraged to reduce the risk of transfer of healthcare-associated pathogens.

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.

Investigation of a cluster of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in a hospital administration building.

OBJECTIVE: To investigate a cluster of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in employees working on 1 floor of a hospital administration building. METHODS: Contact tracing was performed to identify potential exposures and all employees were tested for SARS-CoV-2. Whole-genome sequencing was performed to determine the relatedness of SARS-CoV-2 samples from infected personnel and from control cases in the healthcare system with coronavirus disease 2019 (COVID-19) during the same period. Carbon dioxide levels were measured during a workday to assess adequacy of ventilation; readings >800 parts per million (ppm) were considered an indication of suboptimal ventilation. To assess the potential for airborne transmission, DNA-barcoded aerosols were released, and real-time polymerase chain reaction was used to quantify particles recovered from air samples in multiple locations. RESULTS: Between December 22, 2020, and January 8, 2021, 17 coworkers tested positive for SARS-CoV-2, including 13 symptomatic and 4 asymptomatic individuals. Of the 5 cluster SARS-CoV-2 samples sequenced, 3 were genetically related, but these employees denied higher-risk contacts with one another. None of the sequences from the cluster were genetically related to the 17 control sequences of SARS-CoV-2. Carbon dioxide levels increased during a workday but never exceeded 800 ppm. DNA-barcoded aerosol particles were dispersed from the sites of release to locations throughout the floor; 20% of air samples had >1 log10 particles. CONCLUSIONS: In a hospital administration building outbreak, sequencing of SARS-CoV-2 confirmed transmission among coworkers. Transmission occurred despite the absence of higher-risk exposures and in a setting with adequate ventilation based on monitoring of carbon dioxide levels.

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.

A randomized trial of ultraviolet-C (UV-C) light versus sodium hypochlorite delivered by an electrostatic sprayer for adjunctive decontamination of hospital rooms.

In a randomized trial, adjunctive ultraviolet-C light treatment with a room decontamination device and sodium hypochlorite delivered via an electrostatic sprayer were similarly effective in significantly reducing residual healthcare-associated pathogen contamination on floors and high-touch surfaces after manual cleaning and disinfection. Less time until the room was ready to be occupied by another patient was required for electrostatic spraying.