Transfer of Phi6 bacteriophage between human skin and surfaces common to consumer-facing environments.

AIMS: This study aimed to determine the extent of Phi6 (Φ6) transfer between skin and surfaces relevant to consumer-facing environments based on inoculum matrix, surface type and contact time. METHODS AND RESULTS: Φ6 transfer rates were determined from skin-to-fomite and fomite-to-skin influenced by inoculum matrix (artificial saliva and tripartite), surface type (aluminium, plastic, stainless steel, touchscreen, vinyl and wood) and contact time (5 and 10 s). Significant differences in estimated means were observed based on surface type (both transfer directions), inoculum matrix (skin-to-fomite) and contact time (both transfer directions). During a sequential transfer experiment from fomite-to-skin, the maximum number of consecutive transfer events observed was 3.33 ± 1.19, 2.33 ± 1.20 and 1.67 ± 1.21 for plastic, touchscreen and vinyl, respectively. CONCLUSIONS: Contact time significantly impacted Φ6 transfer rates, which may be attributed to skin absorption dynamics. Surface type should be considered for assessing Φ6 transfer rates. SIGNIFICANCE AND IMPACT OF THE STUDY: Although the persistence of Φ6 on fomites has been characterized, limited data are available regarding the transfer of Φ6 among skin and fomites. Determining Φ6 transfer rates for surfaces in consumer-facing environments based on these factors is needed to better inform future virus transmission mitigation strategies.

Surface Inactivation of a SARS-CoV-2 Surrogate with Hypochlorous Acid is Impacted by Surface Type, Contact Time, Inoculum Matrix, and Concentration.

Indirect contact with contaminated surfaces is a potential transmission route for COVID-19. Therefore, it is necessary to investigate convenient and inexpensive surface sanitization methods, such as HOCl, against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The SARS-CoV-2 surrogate, Phi6 (~ 7 log PFU/mL), was prepared in artificial saliva and tripartite matrices, spot inoculated on coupons of either stainless steel or vinyl, and allowed to dry. The coupons were sprayed with either 500 ppm or 1000 ppm HOCl, and remained on the surface for 0 s (control), 5 s, 30 s, or 60 s. Samples were enumerated via the double agar overlay assay. Statistical analysis was completed in R using a generalized linear model with Quasipoisson error approximations. Time, concentration, surface type, and inoculum matrix were all significant contributors to log reduction at P = 0.05. Significant three-way interactions were observed for 1000 ppm, vinyl, and 60 s (P = 0.03) and 1000 ppm, tripartite, and 60 s (P = 0.0121). A significant two-way interaction between vinyl and 60 s was also observed (P = 0.0168). Overall, increased HOCl concentration and exposure time led to increased Phi6 reduction. Notably, the highest estimated mean log reduction was 3.31 (95% CI 3.14, 3.49) for stainless steel at 60 s and 1000 ppm HOCl in artificial saliva, indicating that this method of sanitization may not adequately reduce enveloped viruses to below infective thresholds.

SARS-CoV-2 environmental contamination in COVID-19 patient rooms in a VA medical center

Background: SARS-CoV-2, the virus causing COVID-19 infection, can significantly contaminate environmental surfaces and can remain viable on surfaces for up to 9 days. Although respiratory route remains the most significant mode of transmission, fomites and environmental sources of infection remain a concern for healthcare personnel who are working in dedicated COVID-19 units. We investigated the extent of detectable SARS-CoV-2 contamination in the environment of COVID-19 patients at a single VA hospital, with the intent of identifying potential high-touch surfaces at risk for viral contamination, which could be used to inform the development of simple COVID-19 prevention strategies. Methods: We conducted a cohort study at 1 VA hospital in a unit housing adult veterans admitted with COVID-19 between October and December 2020. In total, 11 swab specimens were collected for PCR analysis (SARS-CoV-2 env gene) from environmental surfaces inside and just outside the rooms of COVID-19 patients one time. Retrospective chart reviews were conducted to provide the SARS-CoV-2 epidemiologic context for environmental detection. Results: In total, 297 swabs were collected from the unit and environmental areas surrounding 27 hospitalized patients: average age, 72.5 years (range, 34–94);100% male;92% non-Hispanic white;average comorbidities, 1.8 (SD, 1.1). Of 297 swabs, 80 (27%) were positive for SARS-CoV-2 and 19 (70%) of 27 patients had at least 1 positive site. The most contaminated site was the floor just outside the patient room (78% positive samples), followed by the patient's bedrail (37%) and chair handle (37%) (Fig. 1). Traditionally high-touch surfaces, such as the door handle (outside patient room) and the light switch, did not have high positivity rates (<15%). Interestingly, both the personal protective equipment (PPE) cart outside patient's room (33%) and the double doors leading out of the unit (19%) were positive, which are surfaces often touched with bare hands after handwashing. Analyses of clinical data are underway to examine whether specific care needs, based on activities of daily living disability, comorbidities, and clinical presentation of COVID-19, predict SARS-CoV-2 environmental contamination. Conclusions: The presence of environmental contamination by SARS-CoV-2 highlights the importance of transmission via direct or indirect contact. Studies targeting high-risk populations are needed to better understand the transmission of SARS-CoV-2 between infected patients and their environment. Our findings also suggest that handwashing and attention to using disinfecting wipes may mitigate the risk of transmission of virus from surfaces that one might consider safe to touch.Funding: NoneDisclosures: None

Postacute sequelae of SARS-CoV-2 (PASC) in nursing home residents: A case–control study

Background: Postacute sequelae of SARS-CoV-2 (PASC) include fatigue, dyspnea, anxiety, and cognitive impairment. Few studies have explored the prevalence or presentation of PASC among nursing home (NH) residents. Method: A case–control study was conducted at 1 NH in Michigan in December 2021. Cases were defined as residents with SARS-CoV-2 infection between November 2, 2020, and October 8, 2021. Controls lived at the same NH during this interval and never tested positive for SARS CoV-2. Patient characteristics were compared between cases and controls using the Fisher exact test and Wilcoxon rank-sum test. Primary outcomes were functional decline, cognition, and adverse health outcomes. Outcomes were assessed by comparing measures on last observation to observations before COVID-19 diagnosis (cases) or to earliest observation (controls). Multivariable logistic regression assessed correlation between COVID-19 diagnosis and outcomes. Results: In total, 152 residents were identified for inclusion (147 included in final analyses, 76 cases, 71 controls);5 were excluded due to insufficient data. We collected the following resident characteristics: 66% were aged ≥80 years;73% were female;95% were non-Hispanic white;82% were long-stay residents;median of 3 comorbidities (IQR, 2–4). The mean number of follow-up observations was 2.60 (SD, 1.25). No significant differences in population characteristics were detected between cases and controls. Moreover, 106 patients (46 cases and 60 controls) had at least 1 follow-up visit and were thus included in the analyses to evaluate long-term outcomes. Among them, cases experienced significant declines in completing transfers (OR 5.65, p Conclusions: Nursing home residents with COVID-19 are more likely to enter hospice and have a higher mortality rate in the year following infection. Survivors experience significant functional decline in basic activities of daily living, specifically in the ability to transfer and dress. Larger studies are needed to further characterize our findings and to design interventions that can help overcome these long-term sequelae from COVID-19.Funding: NoneDisclosures: None

Persistence of SARS-CoV-2 on surfaces and relevance to the food industry.

Determining the prevalence and persistence of viruses outside the human host aids our ability to characterize exposure risk across multiple transmission pathways. Since 2020, the Coronavirus Disease 2019 pandemic has resulted in a surge of research regarding severe acute respiratory syndrome-coronavirus-type 2 (SARS-CoV-2) and its potential to spread via direct and indirect contact transmission routes. Here, the authors discuss the current state of the science concerning SARS-CoV-2 transmission via contaminated surfaces and its persistence on environmental surfaces. This review aims to provide the reader with an overview of the currently published SARS-CoV-2 persistence studies, factors impacting persistence, guidelines for performing persistence studies, limitation of current data, and future directions for assessing SARS-CoV-2 persistence on fomites.

Factors Impacting Persistence of Phi6 Bacteriophage, an Enveloped Virus Surrogate, on Fomite Surfaces.

The persistence of Phi6 (Φ6) bacteriophage on surfaces commonly encountered in consumer-facing environments was evaluated. Φ6 has been utilized as a surrogate for enveloped viruses, including SARS-CoV-2-the causative agent of COVID-19-due to structural similarities, biosafety level 1 (BSL-1) status, and ease of use. Φ6 persistence on fomites was evaluated by characterizing the impact of the inoculum matrix (artificial saliva, phosphate-buffered saline [PBS], tripartite), inoculum level (low and high), and surface type (nonporous-aluminum, stainless steel, plastic, touchscreen, vinyl; porous-wood). Φ6 was inoculated onto surfaces at low and high inoculum levels for each inoculum matrix and incubated (20.54 ± 0.48°C) for up to 168 h. Φ6 was eluted from the surface and quantified via the double agar overlay assay to determine virus survival over time. For nonporous surfaces inoculated with artificial saliva and PBS, significantly higher D values were observed with high inoculum application according to the 95% confidence intervals. In artificial saliva, D values ranged from 1.00 to 1.35 h at a low inoculum and 4.44 to 7.05 h at a high inoculum across inoculation matrices and surfaces. D values for Φ6, regardless of the inoculum level, were significantly higher in tripartite than in artificial saliva and PBS for nonporous surfaces. In contrast with artificial saliva or PBS, D values in tripartite at low inoculum (D values ranging from 45.8 to 72.8 h) were greater than those at high inoculum (D values ranging from 26.4 to 45.5 h) on nonporous surfaces. This study characterized the impact of the inoculum matrix, inoculum level, and surface type on Φ6 survival on various surfaces relevant to fomite transmission in public settings. IMPORTANCE An important consideration in virus contact transmission is the transfer rate between hands and surfaces, which is driven by several factors, including virus persistence on inanimate surfaces. This research characterized Φ6 persistence on surfaces commonly encountered in public settings based on various factors. The inoculum matrix, which simulates the route of transmission, can impact virus persistence, and three separate matrices were evaluated in this study to determine the impact on Φ6 persistence over time. The number of microorganisms has also been suggested to impact persistence, which was evaluated here to simulate real-world contamination scenarios on six surface types. Results from this study will guide future research utilizing Φ6 or other surrogates for enveloped viruses of public health concern.

Environmental Contamination with SARS-CoV-2 in Nursing Homes

Background The COVID-19 pandemic has disproportionately affected nursing home (NH) patients, accounting for 5% of all cases and 32% of all COVID-19 deaths nationwide. Little is known about the frequency and persistence of SARS-CoV-2 environmental contamination in NHs. We characterize SARS-CoV-2 contamination in the rooms of COVID-19 patients and common areas in and around COVID-19 units. Methods A prospective cohort study was conducted at four NHs in Michigan between October 2020 and January 2021. Clinical research personnel obtained swab specimens from high-touch room surfaces of COVID-19 infected patients, up to three times per patient. Weekly swab specimens from six high-touch surfaces in common areas were also obtained. Demographic and clinical data were collected from patient clinical records. Our primary outcome of interest was the probability of SARS-CoV-2 detection from specific environmental surfaces in COVID-19 patient rooms. Results One hundred four patients with COVID-19 were enrolled and followed for 241 visits. Patient characteristics included: 61.5% over the age of 80;67.3% female;89.4% non-Hispanic white;50.1% short-stay. The study population had significant disabilities in activities of daily living (ADL;81.7% dependent in four or more ADLs) and comorbidities including dementia (55.8%), diabetes (40.4%) and heart failure (32.7) (Table 1). Over the 3-month study period, 2087 swab specimens were collected (1896 COVID-19 patient room surfaces, 191 common area swabs). Figure 1 shows contamination rates at sites proximate and distant to the patient bed. SARS-CoV-2 positivity was 28.4% (538/1896 swabs) on patient room surfaces and 3.7% (7/191 swabs) on common area surfaces. Over the course of follow-up, 89.4% (93/104) of patients had SARS-CoV-2 contamination in their room at least once (Figure 2). Environmental contamination detected on enrollment correlated with contamination of the same site during follow-up. Functional independence increased the odds of proximate contamination. Table 1. Clinical and Demographic Characteristics of the Study Population Including Short- and Long-stay Patients Figure 1. Contamination of Environmental Surfaces Relative to Distance from Patient Bed Figure 2. SARS-CoV-2 on Swab Specimens Collected – Patient-level, Visit-level, and Swab-level Conclusion We conclude that environmental contamination of surfaces in the rooms of COVID-19 patients is nearly universal and persistent. Patients with greater independence are more likely than fully dependent patients to contaminate their immediate environment. Disclosures All Authors: No reported disclosures

Environmental contamination with SARS-CoV-2 in nursing homes.

BACKGROUND: SARS-CoV-2 outbreaks in nursing homes (NHs) have been devastating and have led to the creation of coronavirus disease 2019 (COVID-19) units within NHs to care for affected patients. Frequency and persistence of SARS-CoV-2 environmental contamination in these units have not been studied. METHODS: A prospective cohort study was conducted between October 2020 and January 2021 in four Michigan NHs. Swabs from high-touch surfaces in COVID-19-infected patient rooms were obtained at enrollment and follow-up. Demographic and clinical data were collected from clinical records. Primary outcome of interest was the probability of SARS-CoV-2 RNA detection from specific environmental surfaces in COVID-19 patient rooms. We used multivariable logistic regression to assess patient risk factors for SARS-CoV-2 contamination. Pairwise Phi coefficients were calculated to measure correlation of site-specific environmental detection upon enrollment and during follow-up. RESULTS: One hundred and four patients with COVID-19 were enrolled (61.5% >80 years; 67.3% female; 89.4% non-Hispanic White; 51% short stay) and followed up for 241 visits. The study population had significant disabilities in activities of daily living (ADL; 81.7% dependent in four or more ADLs) and comorbidities, including dementia (55.8%), diabetes (40.4%), and heart failure (32.7%). Over the 3-month study period, 2087 swab specimens were collected (1896 COVID-19 patient rooms, 191 common areas). SARS-CoV-2 positivity was 28.4% (538/1896 swabs) on patient room surfaces and 3.7% (7/191 swabs) on common area surfaces. Nearly 90% (93/104) of patients had SARS-CoV-2 contamination in their room at least once. Environmental contamination upon enrollment correlated with contamination of the same site during follow-up. Functional independence increased the odds of proximate contamination. CONCLUSIONS: Environmental detection of viral RNA from surfaces in the rooms of COVID-19 patients is nearly universal and persistent; more investigation is needed to determine the implications of this for infectiousness. Patients with greater independence are more likely than fully dependent patients to contaminate their immediate environment.

Phi 6 recovery from inoculated fingerpads based on elution buffer and methodology.

Phi 6 (Φ6) bacteriophage is a proposed surrogate to study pathogenic enveloped viruses including SARS-CoV-2-the causative agent of COVID-19-based on structural similarities, BSL-1 status, and ease of use. To determine the role of virus-contaminated hands in disease transmission, an enhanced understanding of buffer and method performance for Φ6 recovery needs to be determined. Four buffer types and three methodologies were investigated for the recovery of Φ6 from human fingerpads over a 30 min duration. Phosphate buffered saline (PBS), PBS + 0.1 % Tween, 0.1 M glycine + 3% beef extract, and viral transport medium were evaluated as buffers for recovery of Φ6 via a dish, modified glove juice, and vigorous swabbing method. Φ6 concentrations on fingerpads were determined at 0-, 5-, 10-, and 30-min post-inoculation. While there were observed differences in virus recovery across buffer and method types depending on the time point, log PFU recovery based on buffer type or methodology was not significantly different at any time point (P > 0.05). The results presented in this study will allow for future work on Φ6 persistence, transfer between hands and surfaces, and efficacy of hand hygiene methods to be performed using a well-characterized and validated recovery method.

When planning meets reality: COVID-19 interpandemic survey of Michigan Nursing Homes.

BACKGROUND: Nursing home (NH) populations have borne the brunt of morbidity and mortality of COVID-19. We surveyed Michigan NHs to evaluate preparedness, staffing, testing, and adaptations to these challenges. METHODS: Interpandemic survey responses were collected May 1-12, 2020. We used Pearson's Chi-squared test, Fisher's exact test, and logistic regression to evaluate relationships. RESULTS: Of 452 Michigan NHs contacted via e-mail, 145 (32.1%) opened the survey and of these, 143 (98.6%) responded. Sixty-eight percent of respondents indicated their response plan addressed most issues. NHs reported receiving rapidly changing guidance from many sources. Two-thirds reported shortages of personal protective equipment and other supplies. Half (50%) lacked sufficient testing resources with only 36% able to test residents and staff with suspected COVID-19. A majority (55%) experienced staffing shortages. Sixty-three percent experienced resignations, with front-line clinical staff more likely to resign, particularly in facilities caring for COVID-19 patients (P < .001). Facilities adapted quickly, creating COVID-19 units (78%) to care for patients on site. To reduce isolation, NHs facilitated communication via phone calls (98%), videoconferencing (96%), and window visits (81%). A majority continued to provide requisite therapies (90%). CONCLUSIONS: NHs experienced shortages of resources, testing supplies, and staffing challenges. COVID-19 in the facility was a key predictor of staff resignations. Facilities relied on rapidly changing, often conflicting advice from multiple sources, suggesting high-yield areas of improvement.

Partnering with Local Hospitals and Public Health to Manage COVID-19 Outbreaks in Nursing Homes.

BACKGROUND/OBJECTIVES: Almost half of deaths related to COVID-19 in the United States are linked to nursing homes (NHs). We describe among short-term and long-term residents at three NHs in Michigan the outbreak identification process, universal testing, point prevalence of COVID-19, and subsequent containment efforts, outcomes, and challenges. DESIGN: Outbreak investigation. SETTING: Three NHs in southeast Michigan. PARTICIPANTS: All residents (N = 215) at three NHs (total beds = 356) affiliated with a large academic healthcare system. METHODS: Upon detection of confirmed cases within the facility, each NH in collaboration and consultation with local hospital, public health officials, and parent corporation implemented immediate facility-wide testing and the following intervention measures: cohorting of COVID-19 positive residents; communication regarding testing and results with residents, healthcare professionals, and families; personal protective equipment reeducation and use throughout facilities; and dedicated staffing for infected patients cohorted in a dedicated COVID-19 wing. We collected patient data regarding demographics, symptoms, comorbidities, hospitalization, and 14-day outcomes. RESULTS: A total of 29 cases of COVID-19 were identified at three participating NHs. Nineteen cases of COVID-19 were identified through symptom-triggered testing from March 23 to April 23, 2020; 10 (4.7%) additional cases were identified through universal testing of 215 residents conducted from April 7 to 15, 2020. The hospitalization rate was 37.9%. The case fatality rate was 20.7% (6/29); these patients had multiple comorbidities. No residents who tested positive through the point-prevalence survey required hospitalization, and five were discharged home within 14 days. CONCLUSION: Proactive and coordinated steps between NH medical directors and administrators, referral hospitals including their laboratories, and local public health officials are necessary to rapidly respond to an outbreak and limit the transmission of COVID-19. This coordinated public health approach may save lives, minimize the burden to the healthcare system, and reduce healthcare costs.