Environmental contamination of SARS-CoV-2 in healthcare premises

Air, surface, and wastewater surveillance of SARS-CoV-2; a multimodal evaluation of COVID-19 detection in a built environment

BACKGROUND

Environmental surveillance of infectious organisms holds tremendous promise to reduce human-to-human transmission in indoor spaces through early detection.

OBJECTIVE

In this study we determined the applicability and limitations of wastewater, indoor high-touch surfaces, in-room air, and rooftop exhaust air sampling methods for detecting SARS-CoV-2 in a real world building occupied by residents recently diagnosed with COVID-19.

METHODS

We concurrently examined the results of three 24-hour environmental surveillance techniques, indoor surface sampling, exhaust air sampling and wastewater surveillance, to the known daily census fluctuations in a COVID-19 isolation dormitory. Additionally, we assessed the ability of aerosol samplers placed in the large volume lobby to detect SARS-CoV-2 multiple times per day.

RESULTS

Our research reveals an increase in the number of individuals confirmed positive with COVID-19 as well as their estimated human viral load to be associated with statistically significant increases in viral loads detected in rooftop exhaust aerosol samples (p = 0.0413), wastewater samples (p = 0.0323,), and indoor high-touch surfaces (p < 0.001)). We also report that the viral load detected in lobby aerosol samples was statistically higher in samples collected during presence of occupants whose COVID-19 diagnostic tests were confirmed positive via qPCR compared to periods when the lobby was occupied by either contact-traced (suspected positive) individuals or during unoccupied periods (p = 0.0314 and <2e-16).

SIGNIFICANCE

We conclude that each daily (24h) surveillance method, rooftop exhaust air, indoor high-touch surfaces, and wastewater, provide useful detection signals for building owner/operator(s). Furthermore, we demonstrate that exhaust air sampling can provide spatially resolved signals based upon ventilation exhaust zones. Additionally, we find that indoor lobby air sampling can provide temporally resolved signals useful during short duration sampling periods (e.g., 2-4 hours) even with intermittent occupancy by occupants diagnosed with COVID-19.

IMPACT

Our research demonstrates that aerosol sampling can detect COVID-19 positive individuals in a real world lobby setting during very short occupancy periods. We demonstrate the effectiveness of rooftop exhaust aerosol, surface, and wastewater environmental surveillance in monitoring viral load in building occupants, both at the building scale and with ventilation zone-level resolution for aerosols. We provide actionable data for researchers, health officials and building managers who seek to determine which monitoring method is best for their building or study. This study is relevant in the fields of epidemiology, exposure sciences, biomonitoring, virology, public health, and healthy building design and management.

Severe acute respiratory syndrome coronavirus 2 variants in patients with coronavirus disease 2019 and environmental sampling from the hospital and market during the coronavirus disease 2019 pandemic in Thailand

Limited genomic surveillance data is available for SARS-CoV-2 in Thailand during the second and third wave outbreaks, including both patient and environmental samples. This study investigated the presence of SARS-CoV-2 RNA in patient samples, on frequently touched surfaces, and in environmental swab samples (EVSs) collected from urban markets in Bangkok between April 2021 and August 2022. A total of 78,159 nasopharyngeal swab samples from patients and 327 environmental swab samples from hospital and market settings were collected. SARS-CoV-2 RNA was detected in 3,706 of 78,159 patient samples and one of 327 environmental samples using real-time RT-PCR. In total, 54 patient samples and an environmental sample were subjected to whole-genome sequencing and mass array genotyping, respectively. Only 46 samples passed the quality assessment based on the analysis criteria. The lineages detected included B.1.1.529 (2 samples), B.1.1.7 (15 samples), B.1.351 (3 samples), B.1.36.16 (6 samples), B.1.617.2 (1 sample), AY.102 (1 sample), AY.4 (11 samples), AY.25 (1 sample), BA.1 (1 sample), BA.1.1 (3 samples), and BA.2 (2 samples). The phylogenetic analysis of the viral genome sequences revealed similar lineages during this study period.

Is differential cleaning needed for SARS-CoV-2 beyond standard procedures? A systematic review

Background

There is a substantial risk of indirect transmission of SARS-CoV-2 from contaminated surfaces and objects in healthcare settings.

Aim

To evaluate the effectiveness of enhanced cleaning protocols for high-touch surfaces during COVID-19, focusing on cleaning products, concentrations, contact time, and recommended frequency.

Setting

We focused on research conducted in healthcare settings or where samples were obtained from healthcare environments.

Method

We assessed studies that compared different cleaning, disinfection, sterilisation, or decontamination procedures and cleaning frequency with standard or routine procedures. We prioritised randomised trials, non-randomised controlled trials, controlled before-and-after studies, and interrupted time series analyses carried out between 01 January 2020 and 31 August 2022.

Results

Three studies met our criteria from 2139 references searched. These studies, which took place in Iran, China and the United States, found that routine terminal cleaning and enhanced terminal cleaning with different cleaning enhancements significantly reduced SARS-CoV-2 surface contamination. One of the studies tested residual SARS-CoV-2 levels after routine and terminal cleaning with varying strengths of disinfectant and evaluated the efficacy of two common types of disinfectants in inactivating SARS-CoV-2 on inanimate surfaces in different hospital wards.

Conclusion

Limited evidence supports cleaning strategies that can reduce the transmission of SARS-CoV-2 from surfaces in healthcare settings. Combining various cleaning methods and using multiple disinfectants can effectively reduce surface contamination.

Contribution

Randomised controlled trials are crucial for evaluating cleaning effectiveness. They must outline cleaning protocols, detailing frequency, product concentration and volume, application methods, soil and surface types, and environmental conditions, to provide strong evidence.

Far-UVC (222 nm) irradiation effectively inactivates ssRNA, dsRNA, ssDNA, and dsDNA viruses as compared to germicidal UVC (254 nm)

Ultraviolet-C (UVC) irradiation is being used as an effective approach for the disinfection of pathogenic viruses present in air, surfaces, and water. Recently, far-UVC radiation (222 nm) emitted by KrCl* (krypton-chloride) excimer lamps have been recommended for disinfecting high-risk public spaces to reduce the presence and transmission of infectious viruses owing to limited human health exposure risks as compared to germicidal UVC (254 nm). In this study, the UVC inactivation performances of individual filtered KrCl* excimer lamp (222 nm) and germicidal UVC lamp (254 nm) were determined against four viruses, bacteriophages MS2, Phi6, M13, and T4, having different genome compositions (ssRNA, dsRNA, ssDNA and dsDNA, respectively) and shapes (i.e., spherical (Phi6), linear (M13), and icosahedral (MS2 and T4)). Here, the disinfection efficacies of filtered KrCl* excimer lamp (222 nm) and germicidal UVC lamp (254 nm) were evaluated for highly concentrated virus droplets that mimic the virus-laden droplets released from the infected person and deposited on surfaces as fomites. Filtered KrCl* excimer (222 nm) showed significantly better inactivation against all viruses having different genome compositions and structures compared to germicidal UVC (254 nm). The obtained sensitivity against the filtered KrCl* excimer (222 nm) was found to be in the order, T4 > M13 > Phi6 > MS2 whereas for the germicidal UVC (254 nm) it was T4 > M13 > MS2 > Phi6. These results provide a strong basis to promote the use of filtered KrCl* excimer lamps (222 nm) in disinfecting contagious viruses and to limit the associated disease spread in public places and other high-risk areas.

Distribution and characteristics of bacteria on the hand during oropharyngeal swab collection: Which handwashing points are affected?

AIMS

To identify the contaminated areas of the hand collection and analyse the distribution characteristics of bacteria in the hand after swab collection.

DESIGN

This study used a cross-sectional design.

METHODS

A cross-sectional study sampling 50 pairs of hands (sampling hand and auxiliary hand) of healthcare workers was performed. Ten samples were collected from each participant. The optimal hand hygiene rates and bacterial colony counts of the whole hand and different hand sections without hand hygiene were identified as the primary outcomes.

RESULTS

The optimal hand hygiene rates of the sampling hand and auxiliary hand were 88.8% (222/250) and 91.6% (229/250), respectively. The lowest optimal hand hygiene rates for the sampling hand and the auxiliary hand were both on the dorsal side of the finger and the dorsum of the hand (86.0%, 86.0% vs. 90.0%, 86.0%); the optimal hand hygiene rates for both sites of the sampling hand were 86.0% (43/50), and the optimal hand hygiene rates for the auxiliary hand were 90.0% (45/50) and 86.0% (43/50). The bacteria colony counts did not differ between the sampling hands and auxiliary hand.

CONCLUSIONS

The dorsal side of the finger and dorsum of the hand were the most likely to be contaminated during oropharyngeal swab collection. Therefore, it is essential to pay extra attention to hand hygiene care of these two sites during the collection process to minimize the risk of cross-contamination.

REPORTING METHOD

The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines were adopted in this study.

Loop-Mediated Isothermal Amplification (LAMP): An Innovative Approach for the Environmental Monitoring of SARS-CoV-2

The rapid and accurate detection of SARS-CoV-2 in environmental settings is crucial for effective public health management during the COVID-19 pandemic. This study compares the performance of the Reverse Transcription quantitative polymerase chain reaction (RT-qPCR) and the Reverse Transcription loop-mediated isothermal amplification (RT-LAMP) for SARS-CoV-2 detection from 100 surface samples collected in healthcare environments. The reference method, RT-qPCR, identified a percentage of 25% of positive samples, while RT-LAMP detected a percentage of 27% of positive surfaces. Our findings reveal a sensitivity of 32% and specificity of 75% for RT-LAMP, with a positive predictive value of 30% and a negative predictive value of 77%. The overall accuracy and concordance with RT-qPCR was 64% for both methods. Despite its lower sensitivity compared to RT-qPCR, RT-LAMP had an advantage due to its rapid screening and environmental surveillance, which is particularly useful for confirming negative results. These results underscore the potential of RT-LAMP not only as a valuable method in the environmental monitoring of SARS-CoV-2 but also as a system to control the sanitation process in ordinary and emergency conditions, providing further optimization and validation for its reliability in routine surveillance and outbreak response efforts.

Research progress on environmental stability of SARS-CoV-2 and influenza viruses

We reviewed research on SARS-CoV-2 and influenza virus detection on surfaces, their persistence under various conditions, and response to disinfectants. Viral contamination in community and healthcare settings was analyzed, emphasizing survival on surfaces influenced by temperature, pH, and material. Findings showed higher concentrations enhance survivability at room temperature, whereas stability increases at 4°C. Both viruses decline in low pH and high heat, with influenza affected by salinity. On various material surfaces, SARS-CoV-2 and influenza viruses demonstrate considerable variations in survival durations, and SARS-CoV-2 is more stable than influenza virus. On the skin, both virus types can persist for ≥2 h. Next, we delineated the virucidal efficacy of disinfectants against SARS-CoV-2 and influenza viruses. In daily life, exposure to ethanol (70%), isopropanol (70%), bleach (10%), or hydrogen peroxide (1-3%) for 15-30 min can effectively inactive various SARS-CoV-2 variants. Povidone-iodine (1 mg/mL, 1 min) or cetylpyridinium chloride (0.1 mg/mL, 2 min) may be used to inactive different SARS-CoV-2 variants in the mouth. Chlorine disinfectants (500 mg/L) or ultraviolet light (222 nm) can effectively inhibit different SARS-CoV-2 variants in public spaces. In conclusion, our study provides a scientific basis and practical guidance for reduction of viral persistence (retention of infectivity) on surfaces and environmental cleanliness.

Plastisphere-hosted viruses: A review of interactions, behavior, and effects

Microbial communities, including bacteria, diatoms, and fungi, colonize plastic surfaces, forming biofilms known as the "plastisphere." Recent research has revealed that plastispheres also host a wide range of viruses, sparking interest in microbial ecology and virology. This shared habitat allows viruses to replicate, interact, infect, and spread, potentially impacting the environment and human health. Consequently, viruses attached to microplastics are now recognized to have broad effects on cellular and immune responses. However, the ecology and implications of viruses hosted in plastisphere habitats remain poorly understood, highlighting their fundamental importance as a subject of study. This review explores various pathways for virus attachment to plastispheres, factors influencing these interactions, their impacts within plastisphere and host-associated environments, and associated issues. It also summarizes current research and identifies knowledge gaps. We anticipate that this paper will help improve our predictive understanding of plastisphere viruses in natural settings and emphasizes the need for more research in real-world environments to advance the field.

Physicochemical methods for disinfection of contaminated surfaces - a way to control infectious diseases

This paper represents the reviews of recent advancements in different physicochemical methods for disinfecting contaminated surfaces, which are considered to be responsible for transmitting different bacterial, viral, and fungal infectious diseases. Surface disinfection can be achieved by applying chemicals, UV-based processes, ionization radiation (gamma-ray, X-ray and electron beam), application of self-disinfecting surfaces, no-touch room disinfection methods, and robotic disinfection methods for built-in settings. Application of different chemicals, such as alcohols, hydrogen peroxide, peracetic acid, quaternary ammonium salts, phenol, and iodine solution, are common and economical. However, the process is time-consuming and less efficient. The use of UVC light (wavelength: 200-280 nm, generated by low vapor mercury lamps or pulse xenon light) has gained much attention for disinfecting fomites worldwide. In recent times, the combination of UV and H2O2, based on the principle of the advanced oxidation process, has been applied for disinfecting inanimate surfaces. The process is very efficient and faster than chemical and UV processes. Heavy metals like copper, silver, zinc, and other metals can inactivate microbes and are used for surface modification to produce self-disinfecting surfaces and used in healthcare facilities. In combination with UVB (280-315 nm) and UVA (315-400 nm), titanium oxide has been utilized for disinfecting contaminated surfaces. Ionization radiation, one of the advanced methods, can be used in disinfecting medical devices and drugs. Post-COVID-19 pandemic, the no-touch and robotic disinfection methods utilizing chemicals or UVC lights have received much importance in built-in settings. Among these methods, surface disinfection by applying chemicals by fogging/vaporization and UV radiation methods has been widely reported in the literature compared to other methods.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40201-024-00893-2.

Levels of environmental contamination with SARS-CoV-2 in hospital rooms and salivary viral loads of patients with coronavirus disease 2019

BACKGROUND

Clarifying the presence of viable severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rather than SARS-CoV-2 viral RNA in inpatient rooms is important for infection control of coronavirus disease 2019 (COVID-19). In this study, we investigated levels of viral RNA and viable virus on environmental surfaces and in patient saliva.

METHODS

Environmental samples from 23 sites in hospital rooms were collected every other day until patient discharge. Saliva specimens and samples from the inner surface of patient masks were also collected. Additionally, environmental samples were collected from 46 sites in hospital rooms on discharge day. The samples were examined using quantitative reverse transcription polymerase chain reaction (RT-qPCR) and plaque assays.

RESULTS

The 10 enrolled cases were classified as mild COVID-19, and patients were discharged after 6-9 days. The viral RNA was detected in 12.4% (105/849) of serially collected environmental samples during hospitalization, whereas viable virus was detected only in 0.47% (4/849), which were from sinks and tap levers. Although all patients recovered, three cases retained viable virus in the last saliva specimen collected. In the 15 discharged rooms, viral RNA was detected in 6.6% (45/682) of the samples, and viable virus was detected in only one sample from the sink.

CONCLUSIONS

Although environmental surfaces surrounding patients with COVID-19 were frequently contaminated with viral RNA, the presence of viable virus was rare and limited only to areas around sinks. These results suggest that contact infection risk via fomites in hospital rooms is extremely rare.

Decay pattern of SARS-CoV-2 RNA surface contamination in real residences

The COVID-19 pandemic has provided valuable lessons that deserve deep thought to prepare for the future. The decay pattern of surface contamination by SARS-CoV-2 RNA in the residences of COVID-19 patients is important but still unknown. We collected 2,233 surface samples from 21 categories of objects in 141 residences of COVID-19 patients in Shanghai when attacked by the omicron variant in spring 2022. Several characteristics of the patients and their residences were investigated to identify relevant associations. The decay of contamination was explored to determine the persistence. Approximately 8.7% of the surface samples were tested positive for SARS-CoV-2 RNA. The basin, water tap, and sewer inlet had the highest positive rates, all exceeding 20%. Only time was significantly associated with the level of surface contamination with SARS-CoV-2, showing a negative association. The decrease fit a first-order decay model with a decay rate of 0.77 ± 0.07 day-1, suggesting a 90% reduction in three days. Positive associations between the cumulative number of newly diagnosed patients in the same building and the positive rate of SARS-CoV-2 RNA in the public corridor were significant during the three days. Our results, in conjunction with the likely lower infectivity or viability, demonstrate that fomite transmission played a limited role in COVID-19 spread. The time determined SARS-CoV-2 RNA contamination, which was reduced by three days. This study is the first to show the decay patterns of SARS-CoV-2 contamination in real residential environments, providing insight into the patterns of transmission, as well as community-based prevention and control of similar threats.

Contamination dynamics of personal protective equipment (PPE) by SARS-CoV-2 RNA in a makeshift hospital with COVID-19 positive occupants

Background

Personal protective equipment (PPE) helps protect healthcare workers (HCWs) from infection and prevents cross-contamination. Knowledge of the contamination dynamics of PPE during the management of COVID-19 patients in a makeshift hospital is limited.

Aim

To describe the rate of SARS-CoV-2 contamination in PPE and to assess the change of contamination at different time points.

Methods

HCWs were followed up for up to 4 hours with hourly collection of swab samples from PPE surfaces in a makeshift COVID-19 hospital setting. Swabs were tested using quantitative reverse transcription polymerase chain reaction (RT-qPCR) for SARS-CoV-2 RNA.

Results

SARS-CoV-2 was detected on 50.9% of the 1620 swabbed samples from 9 different sites of full-body PPE worn by HCWs. The proportion of sites contaminated with SARS-CoV-2 RNA varied from 10.6% to 95.6%. Viral RNA was most frequently detected from the sole of the outer foot cover (95.6%) and least frequently on the face shield (10.6%). The median Ct values among positive samples were 34.20 (IQR, 32.61-35.22) and 34.05 (IQR, 32.20-35.39) for ORF1ab and N genes, respectively. The highest rate of contamination with SARS-CoV-2 RNA for the PPE swab samples was found after 3 hours of use. The positive rate of outer surface of HEPA filters from air supply device was 82.1% during the full capacity period of the makeshift hospital.

Conclusion

A higher rate of contamination was identified at 3 hours after the entrance to the COVID-19 patient care area. Virus-containing aerosols were trapped in the HEPA filter of air supply equipment, representing a potential protective factor against infection to HCWs.

Evaluating the Triage of Suspected COVID-19 Cases in Sudan's Emergency Settings: A Clinical Audit

Background

The inevitable coronavirus disease 2019 global pandemic has severely affected Sudan's fragile healthcare system. The authors share the experience of COVID-19 triage in the emergency departments of five public hospitals in Khartoum state, Sudan.

Methods

A clinical audit was conducted in December 2020 using the Centers for Disease Control and Prevention Checklist and Monitoring Tool for Triage of Suspected COVID-19 Cases. The tool was categorised into 5 domains and 38 indicators.

Results

Only three hospitals had hand hygiene stations in their triage areas: Ibrahim Malik, Omdurman, and Al-Nau. Omdurman Teaching Hospital was the sole hospital with a designated respiratory waiting area. At Al-Nau and Omdurman Hospitals, all respiratory symptomatic patients wore a facemask or alternative. Ibrahim Malik and Bahri Teaching Hospitals had 60% and 50% compliance, respectively, while none at El-Tamayouz Hospital did. No posters or job aids were present in donning and doffing areas. Heavy duty gloves were worn only at Ibrahim Malik (50%) and Omdurman (20%). 100% of staff wore closed-toe footwear at Ibrahim Malik and Omdurman, 75% at El-Tamayouz, 63% at Bahri, and none at Al-Nau.

Conclusion

The healthcare facilities displayed significant shortcomings in preparedness and response to COVID-19, with variations across hospitals in infrastructure, human resources, and procedures. To better combat future outbreaks, systemic improvements and a focused approach on consistent staff training, standard triage algorithms, and adequate PPE availability are imperative.

Methods for virus recovery from environmental surfaces to monitor infectious viral contamination

Accurate quantification of infectious contaminants on environmental surfaces, particularly infectious viruses, is essential for contact transmission risk assessment; however, difficulties in recovering viruses from surfaces using swabs complicates this quantification process. Herein, we identified the factors that significantly affected virus recovery rates and developed an ideal swab method that yielded the highest rate of virus recovery. We comprehensively analyzed the effects of swab type (cotton/polyester), swab water content (wet/dry conditions), surface material, and surface area on the rates of viral RNA and infectious virus recovery. The virus recovery rate was significantly lower than the viral RNA recovery rate (P < 0.01), indicating difficulty in the quantification of infectious viruses. The virus recovery rate was significantly higher under wet conditions than that under dry conditions (P < 0.006), and the virus recovery rate obtained using cotton swabs was significantly higher than that using polyester swabs (P < 0.0001). Furthermore, the virus recovery rate had a strong negative correlation (correlation coefficient >0.8) with the target surface area. The maximum surface area where the virus recovery rate was ≥10% (MSA-10%) was identified as the maximum quantifiable area. For influenza virus recovery, MSA-10% on polyvinyl chloride (PVC) sheet, PVC leather, stainless steel, silicone, glass, and polycarbonate surfaces was 66.7, 193, 60.2, 144, 105, and 15.6 cm2, respectively. For feline calicivirus recovery, MSA-10% on PVC sheet, PVC leather, stainless steel, silicone, glass, and polycarbonate surfaces was 210, 111, 2120, 250, 322, and 180 cm2, respectively. The most accurate and ideal method for quantifying infectious viruses on environmental surfaces with the highest recovery rates meets three specifications: "wet conditions," "the use of cotton swabs," and "a target surface area of approximately 10 cm2.

Virus on surfaces: Chemical mechanism, influence factors, disinfection strategies, and implications for virus repelling surface design

While SARS-CoV-2 is generally under control, the question of variants and infections still persists. Fundamental information on how the virus interacts with inanimate surfaces commonly found in our daily life and when in contact with the skin will be helpful in developing strategies to inhibit the spread of the virus. Here in, a critically important review of current understanding of the interaction between virus and surface is summarized from chemistry point-of-view. The Derjaguin-Landau-Verwey-Overbeek and extended Derjaguin-Landau-Verwey-Overbeek theories to model virus attachments on surfaces are introduced, along with the interaction type and strength, and quantification of each component. The virus survival and transfer are affected by a combination of biological, physical, and chemical parameters, as well as environmental parameters. The surface properties for virus and virus survival on typical surfaces such as metals, plastics, and glass are summarized. Attention is also paid to the transfer of virus to/from surfaces and skin. Typical virus disinfection strategies utilizing heat, light, chemicals, and ozone are discussed together with their disinfection mechanism. In the last section, design principles for virus repelling surface chemistry such as surperhydrophobic or surperhydrophilic surfaces are also introduced, to demonstrate how the integration of surface property control and advanced material fabrication can lead to the development of functional surfaces for mitigating the effect of viral infection upon contact.

Evaluation of the impact of different disinfectants on new coronavirus and human health

A new health threat was appeared in 2019 known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or coronavirus disease 2019 (COVID-19). The new coronavirus distributed all over the world and caused millions of deaths. One way to incomplete the process of COVID-19 transfer from one person to another is using disinfectants. A narrative review study was done on manuscript published documents about the stability of the virus, different types of disinfectants and the effects of disinfectants on SARS-CoV2 and environment from 2005 to 2022 based on Searched databases included Google Scholar, Springer, PubMed, Web of Science and Science Direct (Scopus). All relevant studies published 2005 until 2022 gathered. According to the databases, 670 articles were retrieved. Thirty studies were screened after review and 30 full-text articles entered into the analysis process. Finally, 14 articles were selected in this study. New coronavirus could survive until 9 days in room temperature; the surviving time decreases if temperature increases. The virus can survive in various plastic, glass, and metal surfaces for hours to days. Disinfectants, such as alcohol, isopropanol, formaldehyde, glutaraldehyde, and ethanol, can kill 70-90% viruses in up to 30 s but should be noted that these disinfectants are recognized by Occupational Safety and Health Administration (OSHA) as a potential carcinogen. According to the different reports, increased duration and level of disinfectant exposure can have negative impacts on human and animal health including upper and lower respiratory tract irritation, inflammation, edema, ulceration, and allergic reactions.

SARS-CoV-2 surface contamination in metro-Atlanta grocery stores

While the COVID-19 pandemic has had a detrimental impact on many businesses worldwide, essential businesses, such as grocery stores, continued to operate despite potential disease transmission. Although the principal mode by which people are infected with SARS-CoV-2, the virus that causes COVID-19, is through exposure to respiratory droplets and very small particles carrying infectious virus, contaminated surfaces might play a role in transmission. We collected swab samples from frequently touched surfaces, including grocery carts, touchscreen monitors, credit card keypads, pharmacy counters, self-service food utensils, and refrigerator and freezer handles, in two metro-Atlanta grocery stores over the course of two sampling events in March 2021. Of the 260 swab samples collected, 6 (2.3%) samples were positive for SARS-CoV-2 RNA by reverse transcriptase quantitative polymerase chain reaction. Positive samples were collected from pharmacy (12.0% [3/25] samples), refrigerator/freezer aisles (2.5% [1/39] samples), and self-service food court (5.0% [2/40] samples) areas. Table/counter edge and underside surfaces represented 33% (2/6) of positive samples. These data suggest that risk of exposure to SARS-CoV-2 from frequently touched surfaces in grocery store settings is likely low; however, more frequent cleaning of surfaces in pharmacy and self-service food courts might be warranted.

Contamination of SARS-CoV-2 RNA on personal protective equipment and environmental surfaces in nonpatient entry area of a Fangcang shelter hospital

OBJECTIVES

To determine the extent of contamination of personal protective equipment (PPE) and surfaces by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the nonpatient entry area of a Fangcang shelter hospital, the medical staff accommodation area, and the staff transport bus.

METHODS

We collected 816 samples from the nonpatient entry area and floors in a Fangcang shelter hospital, medical staff accommodation area, and scheduled bus, and the five major types of PPE used from April 13 to May 18, 2022. SARS-CoV-2 ribonucleic acid (RNA) was detected by reverse transcription-polymerase chain reaction.

RESULTS

Overall, 22.2% of PPE samples were positive for SARS-CoV-2 RNA. Boot covers and gowns were the most contaminated types of PPE. The positive PPE contamination rate of staff collecting respiratory specimens was significantly higher than that of the general-treatment staff group (35.8% vs. 12.2%) and cleaner group (35.8% vs. 26.4%), p < 0.01. In total, 27 of 265 (10.2%) environmental surface samples were positive for SARS-CoV-2 RNA. The contamination-positive rates were 26.8% (22/82), 5.4% (4/74), and 0.9% (1/109) for contaminated, potentially contaminated, and clean zones, respectively. SARS-CoV-2 RNA was frequently detected on objects such as mobile phones, tables, computer keyboards and mice, and door handles.

CONCLUSIONS

SARS-CoV-2 RNA was widely distributed on high-touch surfaces and on PPE in the contaminated zone of the Fangcang shelter hospital, implying a potentially high infection risk for healthcare workers. Our findings emphasize the need to ensure adequate environmental cleaning, improve hand hygiene, and reduce the risk of infection. Additionally, prevention of self-contamination during PPE donning and doffing is complex and needs more research.

Designing 3D-Printed Mesh-Covered Fluid Collecting Racks (MFCRs) to Prevent Moisture-Related COVID-19 Sampling Interruptions in Taiwan

Background: A sampling platform (or table) set at the patient's side in a zero-exposure screening center (booth) might be used for specimen collection during public health crises such as the COVID-19 pandemic. However, repeated sanitization causes moisture problems. Such moisture problems would not only be noted by patients but also interrupt the sampling process. In this study, we aimed to develop 3D-printed mesh-covered fluid collecting racks (MFCRs) to address surface moisture problems to determine whether MFCRs can shorten the sampling time. Methods: This was an observational, descriptive, and cross-sectional study. We observed the reasons for sampling interruptions related to surface moisture problems among patients who used MFCRs or did not (April 28-30, 2022). We used a 3D printer to make an MFCR, which measured 14.5 cm in width and length and 1.0 cm in height. The MFCR allows the ethanol to drain through the mesh into the fluid collection rack below to leave a relatively dry surface on the mesh. Finally, we calculated the median time to finish sampling between MFCRs and non-MFCRs. Results: A total of 400 patients were randomly observed (using MFCRs, n = 200; non-MFCRs, n = 200). Patients in the non-MFCR group were more likely to interrupt the sampling process (n = 39, 19.5%) by noting surface moisture problems than those in the MFCR group (n = 3, 1.5%). Two of the major interruptions, "asking questions about the moist surface" (from 12% to 1%) and "slowing down their actions" (from 4.5% to 0.5%), were obviously improved by using MFCRs. Overall, the median sampling time was significantly shorter (p < 0.001) in the group using MFCRs (0.6 min) than in the group using non-MFCRs (1.5 min). The MFCRs shortened the sampling time by 60%, which might be associated with decreasing interruptions caused by surface moisture problems. Conclusions: The 3D printed MFCRs are suitable for handling surface moisture problems caused by repeated sanitizations. More importantly, the MFCRs might be associated with decreasing interruptions caused by moisture problems.

Microplastics as vectors of chemical contaminants and biological agents in freshwater ecosystems: Current knowledge status and future perspectives

Microplastics (MPs) are becoming ubiquitous, and their environmental fate is becoming an issue of concern. Our review aims to synthesize current knowledge status and provide future perspectives regarding the vector effect of MPs for chemical contaminants and biological agents. The evidence in the literature indicates that MPs are a vector for persistent organic pollutants (POPs), metals and pharmaceuticals. Concentrations of chemical contaminant in orders of six-fold higher on MPs surfaces than in the surrounding environmental waters have been reported. Chemical pollutants such as perfluoroalkyl substances (PAFSs), hexachlorocyclohexane (HCHs) and polycyclic aromatic hydrocarbons (PAHs), exhibiting polarities in the range of 3.3-9 are the commonest chemicals reported on MP surfaces. Regarding metals on MPs including chromium (Cr), lead (Pb), cobalt (Co), the presence of C-O and N-H in MPs promote a relatively high adsorption of these metals onto MP surfaces. Regarding pharmaceuticals, not much has been done, but a few studies indicate that commonly used drugs such as ibuprofen, ibuprofen, diclofenac, and naproxen have been associated with MPs. There is sufficient evidence supporting the claim that MPs can act as vectors for viruses, bacterial and antibiotic-resistant bacteria and genes, and MPs act to accelerate horizontal and vertical gene transfer. An area that deserves urgent attention is whether MPs can act as vectors for invertebrates and vertebrates, mainly non-native, invasive freshwater species. Despite the ecological significance of invasive biology, little research has been done in this regard. Overall, our review summarises the state of the current knowledge, identifies critical research gaps and provides perspectives for future research.

Inactivation characteristics of a 280 nm Deep-UV irradiation dose on aerosolized SARS-CoV-2

A non-filter virus inactivation unit was developed that can control the irradiation dose of aerosolized viruses by controlling the lighting pattern of a 280 nm deep-UV (DUV)-LED and the air flowrate. In this study, the inactivation properties of aerosolized SARS-CoV-2 were quantitatively evaluated by controlling the irradiation dose to the virus inside the inactivation unit. The RNA concentration of SARS-CoV-2 remained constant when the total irradiation dose of DUV irradiation to the virus exceeded 16.5 mJ/cm2. This observation suggests that RNA damage may occur in regions below the detection threshold of RT-qPCR assay. However, when the total irradiation dose was less than 16.5 mJ/cm2, the RNA concentration monotonically increased with a decreasing LED irradiation dose. However, the nucleocapsid protein concentration of SARS-CoV-2 was not predominantly dependent on the LED irradiation dose. The plaque assay showed that 99.16% of the virus was inactivated at 8.1 mJ/cm2 of irradiation, and no virus was detected at 12.2 mJ/cm2 of irradiation, resulting in a 99.89% virus inactivation rate. Thus, an irradiation dose of 23% of the maximal irradiation capacity of the virus inactivation unit can activate more than 99% of SARS-CoV-2. These findings are expected to enhance versatility in various applications. The downsizing achieved in our study renders the technology apt for installation in narrow spaces, while the enhanced flowrates establish its viability for implementation in larger facilities.

Environmental sampling for SARS-CoV-2 in long term care facilities: lessons from a pilot study

Background: The SARS-CoV-2 pandemic has highlighted the risk of infection in long-term care facilities (LTCF) and the vulnerability of residents to severe outcomes. Environmental surveillance may help detect pathogens early and inform Infection Prevention and Control (IPC) measures in these settings. Methods: Upon notification of SARS-CoV-2 outbreaks, LTCF within a local authority in South West England were approached to take part in this pilot study. Investigators visited to swab common touch-points and elevated 'non-touch' surfaces (>1.5m above ground level) and samples were analysed for presence of SARS-CoV-2 genetic material (RNA). Data were collected regarding LTCF infrastructure, staff behaviours, clinical and epidemiological risk factors for infection (staff and residents), and IPC measures. Criteria for success were: recruitment of three LTCF; detection of SARS-COV-2 RNA; variation in proportion of SARS-CoV-2 positive surfaces by sampling zone; and collection of clinical and epidemiological data for context. Results: Three LTCFs were recruited, ranging in size and resident demographics. Outbreaks lasted 63, 50 and 30 days with resident attack rates of 53%, 40% and 8%, respectively. The proportion of sample sites on which SARS-CoV-2 was detected was highest in rooms occupied by infected residents and varied elsewhere in the LTCF, with low levels in a facility implementing enhanced IPC measures. The heterogeneity of settings and difficulty obtaining data made it unfeasible to assess association between environmental contamination and infection. A greater proportion of elevated surfaces tested positive for SARS-CoV-2 RNA than common touch-points. Conclusions: SARS-CoV-2 RNA can be detected in a variety of LTCF outbreak settings, both on common-touch items and in elevated sites out of reach. This suggests that further work is justified, to assess feasibility and utility of environmental sampling for infection surveillance in LTCF.

A longitudinal environmental surveillance study for SARS-CoV-2 from the emergency department of a teaching hospital in Hong Kong

BACKGROUND

Understanding factors associated with SARS-CoV-2 exposure risk in the hospital setting may help improve infection control measures for prevention.

AIM

To monitor SARS-CoV-2 exposure risk among healthcare workers and to identify risk factors associated with SARS-CoV-2 detection.

METHODS

Surface and air samples were collected longitudinally over 14 months spanning 2020-2022 at the Emergency Department (ED) of a teaching hospital in Hong Kong. SARS-CoV-2 viral RNA was detected by real-time reverse-transcription polymerase chain reaction. Ecological factors associated with SARS-CoV-2 detection were analysed by logistic regression. A sero-epidemiological study was conducted in January to April 2021 to monitor SARS-CoV-2 seroprevalence. A questionnaire was used to collect information on job nature and use of personal protective equipment (PPE) of the participants.

FINDINGS

SARS-CoV-2 RNA was detected at low frequencies from surfaces (0.7%, n=2562) and air samples (1.6%, n=128). Crowding was identified as the main risk factor, as weekly ED attendance (OR=1.002, p=0.04) and sampling after peak-hours of ED attendance (OR=5.216, p=0.03) were associated with the detection of SARS-CoV-2 viral RNA from surfaces. The low exposure risk was corroborated by the zero seropositive rate among 281 participants by April 2021.

CONCLUSION

Crowding may introduce SARS-CoV-2 into ED through increased attendances. Multiple factors may have contributed to the low contamination of SARS-CoV-2 at the ED, including hospital infection control measures for screening ED attendees, high PPE compliance among healthcare workers, and various public health and social measures implemented to reduce community transmission in Hong Kong where a dynamic zero COVID-19 policy was adopted.

Surface Disinfection Practice in Public Hospitals in the Era of COVID-19: Assessment of Disinfectant Solution Preparation and Use in Addis Ababa, Ethiopia

Background

Surface disinfection of healthcare facilities with appropriate disinfectants is among the infection control strategies against the spread of coronavirus disease 2019 (COVID-19). As sodium hypochlorite solution (SHS) is a commonly used surface disinfectant, its preparation and proper use should be given a due attention. The current study aimed at assessing the practice of Addis Ababa public hospitals in the preparation and use of SHS.

Methods

A cross-sectional observational study was employed to assess the adequacy of disinfectant solution preparation and use. Checklists were used for data collection. Descriptive statistics were used for data analyses, and categorical variables were described by frequencies and percentages.

Results

Out of the twelve public hospitals included in the study; only three hospitals checked the potency of the working SHS. Majority of the hospitals (8 hospitals) stored the concentrated SHS products in cool, dry, and direct sunlight protected places. It was only in one hospital where appropriate personal protective equipment was used during the preparation and quality control activities. Surfaces were not cleaned in all hospitals before disinfection; and the rooms were ventilated only in 2 hospitals during the application of the disinfectant solution.

Conclusion

The study revealed that the preparations of SHS in the public hospitals did not comply with most of the requirements of good compounding practice. Moreover, standard practices were not maintained in majority hospitals during the use of SHS for surface disinfection. As a control strategy in the spread of COVID-19 and other infections, appropriate corrective actions shall be implemented in the studied hospitals to mitigate the limitations observed in the preparation and use of SHS.

Antibacterial, antiviral, and biodegradable collagen network mask for effective particulate removal and wireless breath monitoring

Functional face masks that can effectively remove particulate matter and pathogens are critical to addressing the urgent health needs arising from industrial air pollution and the COVID-19 pandemic. However, most commercial masks are manufactured by tedious and complicated network-forming procedures (e.g., meltblowing and electrospinning). In addition, the materials used (e.g., polypropylene) have significant limitations such as a lack of pathogen inactivation and degradability, which can cause secondary infection and serious environmental concerns if discarded. Here, we present a facile and straightforward method for creating biodegradable and self-disinfecting masks based on collagen fiber networks. These masks not only provide superior protection against a wide range of hazardous substances in polluted air, but also address environmental concerns associated with waste disposal. Importantly, collagen fiber networks with naturally existing hierarchical microporous structures can be easily modified by tannic acid to improve its mechanical characteristics and enable the in situ production of silver nanoparticles. The resulting masks exhibit excellent antibacterial (>99.99%, 15 min) and antiviral (>99.999%, 15 min) capabilities, as well as high PM_2.5 removal efficiency (>99.9%, 30 s). We further demonstrate the integration of the mask into a wireless platform for respiratory monitoring. Therefore, the smart mask has enormous promise for combating air pollution and contagious viruses, managing personal health, and alleviating waste issues caused by commercial masks.

Viral contamination on the surfaces of the personal protective equipment among health care professionals working in COVID-19 wards: A single-center prospective, observational study

OBJECTIVE

To evaluate potential viral contamination on the surfaces of personal protective equipment (PPE) in COVID-19 wards.

METHODS

Face shields, gloves, the chest area of PPE and shoe soles were sampled at different time points. The samples were tested for the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by PCR, and the cycle threshold (CT) values were recorded.

RESULTS

The positive rate was 74.7% (239/320) for all PPE specimens. The CT values of the samples were ranked in the following order: face shields > chests > gloves > shoe soles (37.08±1.38, 35.48±2.02, 34.17±1.91 and 33.52±3.16, respectively; P for trend < .001). After disinfection, the CT values of shoe soles decreased compared with before disinfection (32.78±3.47 vs. 34.3±2.61, P = .037), whereas no significant effect of disinfection on the CT values of face shields, chests and gloves was observed. After disinfection, the CT values of specimens collected from shoe soles gradually increased; before disinfection, the CT values of shoe sole specimens were all less than 35.

CONCLUSIONS

SARS-CoV-2 can attach to the surfaces of the PPE of healthcare professionals in COVID-19 wards, especially the shoe soles and undisinfected gloves. Shoe soles had the highest SARS-CoV-2 loads among all tested PPE items.

Assessing the thermal stability of toolmarks casting materials through optical comparison microscopy, virtual comparison microscopy and quantitative similarity scores

Toolmarks, particularly those found on bulky, inaccessible or immovable items, can be recovered by casting. To allow for subsequent comparative examinations, the casting material, typically polysiloxanes or silicones, must be able to capture and preserve fine details within a toolmark accurately. To study the stability of such details after exposure to heat, toolmark casts were heated at either 60 °C for 2 h, or 90 °C for 1 h. These casts were subsequently compared to casts that had not been exposed to heat, using traditional optical comparison microscopy, as well as virtual comparison microscopy. Digitised toolmark signatures were also extracted from the casts and compared pairwise to obtain quantitative similarity scores based on cross-correlation, consecutive matching striae and Mann-Whitney U-statistic. Our results show that the fine surface details captured on all four commercial toolmark casting materials tested herein remained stable after exposure to heat. This study shows that the above heating protocols are viable viral inactivation methods for toolmark casts that are potentially contaminated with human coronaviruses, such as SARS-CoV-2. Our findings also apply to other scenarios, such as for casts that were left in a vehicle parked under the sun.

Efficacy of copper blend coatings in reducing SARS-CoV-2 contamination

SARS-CoV-2 is a highly infectious virus and etiologic agent of COVID-19, which is spread by respiratory droplets, aerosols, and contaminated surfaces. Copper is a known antiviral agent, and has resulted in successful reduction of pathogens and infections by 83-99.9% when coated on surfaces in intensive care units. Additionally, copper has been shown to inactivate pathogens such as Coronavirus 226E, a close relative of SARS-CoV-2. Here, we examine the ability of two copper blends with differing compositions to inactivate SARS-CoV-2 virus at different time points. Copper Blend 2 (75.07% pure copper) was found to significantly reduce (over 50%) the viability of SARS-CoV-2 at 5 min of contact, with at least 98% reduction in recovered virus at 20 min (vs. plastic control). However, Copper Blend 1 (48.26% pure copper), was not found to significantly reduce viability of SARS-CoV-2 at any time point when compared to plastic. This may indicate that there is an important percentage of copper content in materials that is needed to effectively inactivate SARS-CoV-2. Overall, this study shows that over the course of 20 min, coatings made of copper materials can significantly reduce the recovery of infectious SARS-CoV-2 compared to uncoated controls, indicating the effective use of copper for viral inactivation on surfaces. Furthermore, it may suggest higher copper content has stronger antiviral properties. This could have important implications when short turnaround times are needed for cleaning and disinfecting rooms or equipment, especially in strained healthcare settings which are struggling to keep up with demand.

Investigation on the effectiveness of ventilation dilution on mitigating COVID-19 patients' secondary airway damage due to exposure to disinfectants

Chlorine-containing disinfectants are widely used in hospitals to prevent hospital-acquired severe acute respiratory syndrome coronavirus 2 infection. Meanwhile, ventilation is a simple but effective means to maintain clean air. It is essential to explore the exposure level and health effects of coronavirus disease 2019 patients' inhalation exposure to by-products of chloride-containing disinfectants under frequent surface disinfection and understand the role of ventilation in mitigating subsequent airway damage. We determined ventilation dilution performance and indoor air quality of two intensive care unit wards of the largest temporary hospital constructed in China, Leishenshan Hospital. The chloride inhalation exposure levels, and health risks indicated by interleukin-6 and D-dimer test results of 32 patients were analysed. The mean ± standard deviation values of the outdoor air change rate in the two intensive care unit wards were 8.8 ± 1.5 h-1 (Intensive care unit 1) and 4.1 ± 1.4 h-1 (Intensive care unit 2). The median carbon dioxide and fine particulate matter concentrations were 480 ppm and 19 μg/m3 for intensive care unit 1, and 567 ppm and 21 μg/m3 for intensive care unit 2, all of which were around the average levels of those in permanent hospitals (579 ppm and 21 μg/m3). Of these patients, the median (lower quartile, upper quartile) chloride exposure time and calculated dose were 26.66 (2.89, 57.21) h and 0.357 (0.008, 1.317) mg, respectively. A statistically significant positive correlation was observed between interleukin-6 and D-dimer concentrations. To conclude, ventilation helped maintain ward air cleanliness and health risks were not observed.

Environmental Contamination by SARS-CoV-2 During Noninvasive Ventilation in COVID-19

BACKGROUND

Environmental contamination by SARS-CoV-2 from patients with COVID-19 undergoing noninvasive ventilation (NIV) in the ICU is still under investigation. This study set out to investigate the presence of SARS-CoV-2 on surfaces near subjects receiving NIV in the ICU under controlled conditions (ie, use of dual-limb circuits, filters, adequate room ventilation).

METHODS

This was a single-center, prospective, observational study in the ICU of a tertiary teaching hospital. Four surface sampling areas, at increasing distance from subject's face, were identified; and each one was sampled at fixed intervals: 6, 12, and 24 h. The presence of SARS-CoV-2 was detected with real-time reverse transcriptase-polymerase-chain-reaction (RT-PCR) test on environmental swabs; the RT-PCR assay targeted the SARS-CoV-2 virus nucleocapsid N1 and N2 genes and the human RNase P gene as internal control.

RESULTS

In a total of 256 collected samples, none were positive for SARS-CoV-2 genetic material, whereas 21 samples (8.2%) tested positive for RNase P, thus demonstrating the presence of genetic material unrelated to SARS-CoV-2.

CONCLUSIONS

Our data show that application of NIV in an appropriate environment and with correct precautions leads to no sign of surface environmental contamination. Accordingly, our data support the idea that use of NIV in the ICU is safe both for health care workers and for other patients.

Environmental Contamination With SARS-CoV-2 in a Hospital Setting

Background The coronavirus disease 2019 (COVID-19) pandemic is a global concern and has changed the way we practice medicine in acute hospital settings. This is particularly true with regard to patient triage, patient risk assessment, use of personal protective equipment, and environmental disinfection. Transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is primarily through inhalation of respiratory droplets generated through talking, coughing, or sneezing. There is, however, a potential risk that respiratory droplets settling on inanimate surfaces and objects in the hospital environment could provide a reservoir for nosocomial infections in patients and pose a healthcare risk to medical staff. Indeed, there have been previous reports of healthcare-associated outbreaks in hospitals. Several authors have argued that the risk of transmission via fomites may be insignificant. It is, however, not clear what proportion of SARS-CoV-2 infections are attributable to direct contact with fomites; a few reports have indicated possible transmission via this route. Environmental contamination with SARS-CoV-2 in healthcare institutions has been shown to vary according to the function or service provided by a unit or department. Information that identifies hospital areas that have a propensity for higher environmental burden may improve the practice of infection control and environmental cleaning and decontamination in healthcare institutions. This study aimed to investigate environmental SARS-CoV-2 contamination in the clinical areas of patients with COVID-19 infection. Methodology We conducted a cross-sectional study performing swabbing of frequently touched surfaces, equipment, and ventilation ducts in five specific clinical areas of Peterborough City Hospital which is part of the North West Anglia NHS Foundation Trust. The five clinical areas that were chosen for swabbing were the Emergency Department (ED), Intensive Care Unit (ICU), Isolation Ward, Respiratory Ward, and a Gastroenterology Ward that was serving as a receiving ward at the height of the second COVID-19 infection wave in the United Kingdom. Surfaces to be swabbed were divided into the patient zone, doctor zone, and nursing zone. Swabs from the chosen surfaces were collected on two consecutive days. A total of 158 surface swabs were collected during the second wave of the COVID-19 pandemic. SARS-CoV-2 RNA was detected by reverse transcription polymerase chain reaction. Results The most contaminated clinical areas were the three receiving wards where 12% (11/96) of the swabs were positive. Inside the patient rooms, these surfaces included bed rails and controls, bedside tables, television screens, remote control units, and the room ventilation system. Outside the patient room, these surfaces included mobile computers and computer desk surfaces in the doctors' offices. All swabs taken from the ED and ICU were found to be negative. Conclusions Our study confirms the potential infection risks posed by environmental contamination with the SARS-CoV-2 virus. This highlights the importance of adequate environmental cleaning for proper infection control and prevention in healthcare settings.

Current Technologies for Detection of COVID-19: Biosensors, Artificial Intelligence and Internet of Medical Things (IoMT): Review

Despite the fact that COVID-19 is no longer a global pandemic due to development and integration of different technologies for the diagnosis and treatment of the disease, technological advancement in the field of molecular biology, electronics, computer science, artificial intelligence, Internet of Things, nanotechnology, etc. has led to the development of molecular approaches and computer aided diagnosis for the detection of COVID-19. This study provides a holistic approach on COVID-19 detection based on (1) molecular diagnosis which includes RT-PCR, antigen-antibody, and CRISPR-based biosensors and (2) computer aided detection based on AI-driven models which include deep learning and transfer learning approach. The review also provide comparison between these two emerging technologies and open research issues for the development of smart-IoMT-enabled platforms for the detection of COVID-19.

How to reduce the exposure risk of medical staff from SARS-CoV-2 by reducing environmental contamination: Experience from designated hospitals in China

Background

Using daily monitoring of environmental surfaces and personal protective equipment (PPE), we found an increase in environmental contamination since August 18, 2021, in a designated hospital for COVID-19 patients in China, which may lead to an increased risk of exposure to medical staff.

Methods

To investigate the cause of increased environmental contamination and effect of our intervention, we obtained environmental samples at pre-intervention (August 18-21, 2021) and post-intervention (August 22-28, 2021) from six infection isolation rooms with windows for ventilation and other auxiliary areas at 105 and 129 sites before routine daily cleaning, respectively. In addition, we obtained PPE samples from 98 medical staff exiting the patient rooms/contaminated areas at 482 sites. Between August 22 and 24, 2021, we took measures to reduce environmental contamination based on sampling and inspection results.

Findings

At pre-intervention, the positivity rates for contamination of environmental surfaces and PPE samples were significantly higher for critical patients (37.21 and 27.86%, respectively) than severely ill patients (25.00 and 12.50%, respectively) and moderately ill patients (0.00 and 0.00%, respectively) (Pearson's Chi-square: χ² = 15.560, p = 0.000; Fisher's exact test: χ² = 9.358, p = 0.007). Therefore, we inferred that the source of contamination of environmental surfaces and PPE was mainly the room of critically ill patients, likely through the hands of medical staff to the potentially contaminated areas. A critically ill patient had emergency tracheal intubation and rescue on August 18, 2021, due to worsened patient condition. The ventilator tube used for first aid did not match the ventilator, and the ventilator tube fell off multiple times on August 18-21, 2021, which may explain the increased contamination of environmental surfaces and PPE from critically ill patients, as well as lead to indirect contamination of potentially contaminated areas. The contamination positivity rates of environmental surfaces and PPE were reduced by replacing the appropriate ventilator catheter, limiting the number of people entering the isolation room simultaneously, increasing the frequency of environmental disinfection, standardizing the undressing process, setting up undressing monitoring posts to supervise the undressing process, and preventing the spread of virus infections in the hospital during an epidemic.

Conclusions

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was spread on object surfaces in isolation rooms mainly by touch, and the contamination of environmental surfaces and PPE was greater in rooms of patients with greater disease severity and higher surface touch frequency. Therefore, strict protective measures for medical staff, frequent environmental cleaning for isolation rooms, and compliance with mask wearing by patients when conditions permit should be advised to prevent SARS-CoV-2 spread in hospitals.

Pierre Schneider B, Detrick E. SARS-CoV-2 surveillance with environmental surface sampling in public areas

Contaminated surfaces are one of the ways that coronavirus disease 2019 (COVID-19) may be transmitted. SARS-CoV-2 can be detected on environmental surfaces; however, few environmental sampling studies have been conducted in nonclinical settings. The objective of this study was to detect SARS-CoV-2 RNA on environmental surfaces in public areas in Las Vegas, Nevada. In total, 300 surface samples were collected from high-touch surfaces from high-congregate public locations and from a public health facility (PHF) that was visited by COVID-19 patients. Environmental samples were analyzed with quantitative reverse-transcriptase polymerase chain reaction (RT-qPCR) using SARS-CoV-2 specific primers and probes for three target genes. Results showed that 31 out of 300 (10.3%) surface samples tested positive for SARS-CoV-2, 24 at the PHF and 7 in high-congregate public locations. Concentrations ranged from 102 to 106 viral particles per 3 ml sample on a wide variety of materials. The data also showed that the N gene assay had greater sensitivity compared to the S and ORF gene assays. Besides frequently touched surfaces, SARS-CoV-2 was detected in restrooms, on floors and surfaces in contact with floors, as well as in a mop water sample. The results of this study describe the extent and distribution of environmental SARS-CoV-2 contamination in public areas in Las Vegas, Nevada. A method using the N gene PCR assay was developed for SARS-CoV-2 environmental monitoring in public areas. Environmental monitoring with this method can determine the specific sites of surface contamination in the community and may be beneficial for prevention of COVID-19 indirect transmission, and evaluation and improvement of infection control practices in public areas, public health facilities, universities, and businesses.

Review of the impact of COVID-19 on male reproduction, and its implications on assisted reproductive technology services

The announcement in 2019 of a new coronavirus disease that quickly became a major pandemic, is an exceptional challenge to healthcare systems never seen before. Such a public health emergency can largely influence various aspects of people’s health as well as reproductive outcome. IVF specialists should be vigilant, monitoring the situation whilst contributing by sharing novel evidence to counsel patients, both pregnant women and would-be mothers. Coronavirus infection might adversely affect pregnant women and their offspring. Consequently, this review paper aims to analyse its potential risks for reproductive health, as well as potential effects of the virus on gamete function and embryo development. In addition, reopening fertility clinics poses several concerns that need immediate addressing, such as the effect of severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) on reproductive cells and also the potential risk of cross-contamination and viral transmission. Therefore, this manuscript summarizes what is currently known about the effect of the SARS-CoV-2 infection on medically assisted reproductive treatments and its effect on reproductive health and pregnancy.

Overview of the Role of Spatial Factors in Indoor SARS-CoV-2 Transmission: A Space-Based Framework for Assessing the Multi-Route Infection Risk

The COVID-19 pandemic has lasted from 2019 to 2022, severely disrupting human health and daily life. The combined effects of spatial, environmental, and behavioral factors on indoor COVID-19 spread and their interactions are usually ignored. Especially, there is a lack of discussion on the role of spatial factors in reducing the risk of virus transmission in complex and diverse indoor environments. This paper endeavours to summarize the spatial factors and their effects involved in indoor virus transmission. The process of release, transport, and intake of SARS-CoV-2 was reviewed, and six transmission routes according to spatial distance and exposure way were classified. The triangular relationship between spatial, environmental and occupant behavioral parameters during virus transmission was discussed. The detailed effects of spatial parameters on droplet-based, surface-based and air-based transmission processes and virus viability were summarized. We found that spatial layout, public-facility design and openings have a significant indirect impact on the indoor virus distribution and transmission by affecting occupant behavior, indoor airflow field and virus stability. We proposed a space-based indoor multi-route infection risk assessment framework, in which the 3D building model containing detailed spatial information, occupant behavior model, virus-spread model and infection-risk calculation model are linked together. It is also applicable to other, similar, respiratory infectious diseases such as SARS, influenza, etc. This study contributes to developing building-level, infection-risk assessment models, which could help building practitioners make better decisions to improve the building's epidemic-resistance performance.

Human Responses in Public Health Emergencies for Infectious Disease Control: An Overview of Controlled Topologies for Biomedical Applications

COVID-19 originated in Wuhan city of Hubei Province in China in December three years ago. Since then, it has spread to more than 210 countries and territories. This disease is caused by Severe Acute Respiratory Syndrome Coronavirus 2. The virus has a size of one to two nanometers and a single-stranded positive RNA. Droplets spread the virus from coughing and sneezing. This condition causes coughing, fever, acute respiratory problems, and even death. According to the WHO, the virus can survive outside the body for several hours. This research aimed to determine how environmental factors influenced the COVID-19 virus's survival and behavior, as well as its transmission, in a complex environment. Based on the results, virus transmissions are influenced by various human and environmental factors such as population distribution, travel, social behavior, and climate change. Environmental factors have not been adequately examined concerning the transmission of this epidemic. Thus, it is necessary to examine various aspects of prevention and control of this disease, including its effects on climate and other environmental factors.

Elucidating the role of environmental management of forests, air quality, solid waste and wastewater on the dissemination of SARS-CoV-2

The increasing frequency of zoonotic diseases is amongst several catastrophic repercussions of inadequate environmental management. Emergence, prevalence, and lethality of zoonotic diseases is intrinsically linked to environmental management which are currently at a destructive level globally. The effects of these links are complicated and interdependent, creating an urgent need of elucidating the role of environmental mismanagement to improve our resilience to future pandemics. This review focused on the pertinent role of forests, outdoor air, indoor air, solid waste and wastewater management in COVID-19 dissemination to analyze the opportunities prevailing to control infectious diseases considering relevant data from previous disease outbreaks. Global forest management is currently detrimental and hotspots of forest fragmentation have demonstrated to result in zoonotic disease emergences. Deforestation is reported to increase susceptibility to COVID-19 due to wildfire induced pollution and loss of forest ecosystem services. Detection of SARS-CoV-2 like viruses in multiple animal species also point to the impacts of biodiversity loss and forest fragmentation in relation to COVID-19. Available literature on air quality and COVID-19 have provided insights into the potential of air pollutants acting as plausible virus carrier and aggravating immune responses and expression of ACE2 receptors. SARS-CoV-2 is detected in outdoor air, indoor air, solid waste, wastewater and shown to prevail on solid surfaces and aerosols for prolonged hours. Furthermore, lack of protection measures and safe disposal options in waste management are evoking concerns especially in underdeveloped countries due to high infectivity of SARS-CoV-2. Inadequate legal framework and non-adherence to environmental regulations were observed to aggravate the postulated risks and vulnerability to future waves of pandemics. Our understanding underlines the urgent need to reinforce the fragile status of global environmental management systems through the development of strict legislative frameworks and enforcement by providing institutional, financial and technical supports.

Analysis of surface contamination of severe acute respiratory syndrome coronavirus 2 in a health-care setting in the context of the coronavirus disease-2019 pandemic

BACKGROUND

Hospital-onset coronavirus disease-2019 (COVID-19) infection has been reported and is probably linked to ineffective implementation of infection prevention and control measures. Contaminated surfaces and air are considered a key part of the transmission dynamics of severe acute respiratory syndrome, Middle East respiratory syndrome, influenza, and other organisms in hospitals. This study aimed to assess the extent and persistence of surface contamination with COVID-19.

MATERIALS AND METHODS

It was a hospital-based cross-sectional study conducted for a period for 2 weeks from December 03, 2020, to December 16, 2020, in Kathua district of J and K, India. The environmental samples were taken from the patient care area that included COVID isolation ward and intensive care unit (ICU) as per the guidelines of WHO Protocol "Surface sampling of COVID-19: A practical "how to" protocol for health care and public health professionals after seeking copyright permission from the WHO. Universal standard precautions were strictly followed. Descriptive analysis was done using the MS-Excel and expressed in numbers and percentages.

RESULTS

A total of 140 surface samples were taken, 70 each from the COVID ICU and isolation ward. The results of ten samples from the ICU turned out to be positive and 20 samples were positive from the isolation ward. Eleven (78.6%) out of the 14 samples taken from the corners of the ICU and isolation ward were found to be positive.

CONCLUSION

Our study revealed surface contamination in the hospital setting both in COVID ICU and isolation ward particularly from the corners of the COVID ICU and isolation ward followed by the samples taken from the linen. Strict adherence to COVID appropriate behavior, increased frequency of disinfection in high-risk areas, and sensitization of the staff are mandatory to minimize the infection risk.

Superrepellent Doubly Reentrant Geometry Promotes Antibiofouling and Prevention of Coronavirus Contamination

The fomite transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has drawn attention because of its highly contagious nature. Therefore, surfaces that can prevent coronavirus contamination are an urgent and unmet need during the coronavirus disease 2019 (COVID-19) pandemic. Conventional surfaces are usually based on superhydrophobic or antiviral coatings. However, these coatings may be dysfunctional because of biofouling, which is the undesired adhesion of biomolecules. A superhydrophobic surface independent of the material content and coating agents may serve the purpose of antibiofouling and preventing viral transmission. Doubly reentrant topology (DRT) is a unique structure that can meet the need. This study demonstrates that the DRT surfaces possess a striking antibiofouling effect that can prevent viral contamination. This effect still exists even if the DRT surface is made of a hydrophilic material such as silicon oxide and copper. To the best of our knowledge, this work first demonstrates that fomite transmission of viruses may be prevented by minimizing the contact area between pathogens and surfaces even made of hydrophilic materials. Furthermore, the DRT geometry per se features excellent antibiofouling ability, which may shed light on the applications of pathogen elimination in alleviating the COVID-19 pandemic.

Diagnostic Laboratory Characteristics of COVID-19 Patients Infected by Fomites: COVID-19 Outbreak in a South Korean Public Administrative Facility

There is a paucity of data regarding the differentiating characteristics of patients who were infected with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) by fomites around the world. We conducted an event-based outbreak investigation, involving 795 public officers and 277 assistant staff, in the Ministry of Oceans and Fisheries (MOF) or the same building from March 2 to March 18, 2020. The SARS-CoV-2 patients were found to have more frequently touched fomites and used public toilets than those who were tested negative for the virus (cOR, 24.38; 95% CI, 4.95-120.01). Symptoms such as coughing and loss of taste and smell were more frequently found in the office-cleaner group than in the public-officer group. The SARS-CoV-2 office-cleaner patients were more likely to have a high RdRp(Ct) value of PCR (median: 34.17 vs. 24.99; p = 0.035) and E(Ct) value of PCR (median: 32.30 vs. 24.74; p = 0.045). All office cleaner patients (100%) had a ground glass opacity in both lobes. Regarding segmental lung involvement of CT, two patients (100%) had a lesion in the right middle lobe, which invaded the whole lobe later. This implies that the fomite might be a selective risk factor of SARS-CoV-2 infection.

Longitudinal analysis of built environment and aerosol contamination associated with isolated COVID-19 positive individuals

The indoor environment is the primary location for the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), largely driven by respiratory particle accumulation in the air and increased connectivity between the individuals occupying indoor spaces. In this study, we aimed to track a cohort of subjects as they occupied a COVID-19 isolation dormitory to better understand the impact of subject and environmental viral load over time, symptoms, and room ventilation on the detectable viral load within a single room. We find that subject samples demonstrate a decrease in overall viral load over time, symptoms significantly impact environmental viral load, and we provide the first real-world evidence for decreased aerosol SARS-CoV-2 load with increasing ventilation, both from mechanical and window sources. These results may guide environmental viral surveillance strategies and be used to better control the spread of SARS-CoV-2 within built environments and better protect those caring for individuals with COVID-19.

SARS-CoV-2 RNA Detection on Environmental Surfaces in a University Setting of Central Italy

The transmission of SARS-CoV-2 occurs through direct contact (person to person) and indirect contact by means of objects and surfaces contaminated by secretions from individuals with COVID-19 or asymptomatic carriers. In this study, we evaluated the presence of SARS-CoV-2 RNA on surfaces made of different materials located in university environments frequented by students and staff involved in academy activity during the fourth pandemic wave (December 2021). A total of 189 environmental samples were collected from classrooms, the library, computer room, gym and common areas and subjected to real-time PCR assay to evaluate the presence of SARS-CoV-2 RNA by amplification of the RNA-dependent RNA polymerase (RdRp) gene. All samples gave a valid result for Internal Process Control and nine (4.8%) tested very low positive for SARS-CoV-2 RNA amplification with a median Ct value of 39.44 [IQR: 37.31-42.66] (≤1 copy of viral genome). Our results show that, despite the prevention measures implemented, the presence of infected subjects cannot be excluded, as evidenced by the recovery of SARS-CoV-2 RNA from surfaces. The monitoring of environmental SARS-CoV-2 RNA could support public health prevention strategies in the academic and school world.

Compared hand hygiene compliance among healthcare providers before and after the COVID-19 pandemic: A rapid review and meta-analysis

BACKGROUND

Hand hygiene (HH) is a cost-effective measure to reduce health care-associated infections. The overall characteristics and changes of hand hygiene compliance (HHC) among health care providers during the COVID-19 pandemic provided evidence for targeted HH intervention measures.

AIM

To systematically review the literature and conduct a meta-analysis of studies investigating the rate of HHC and the characteristics of HH during the COVID-19 pandemic.

METHODS

The PubMed, Embase, Cochrane Library, Web of Science, CNKI, WanFang Data, VIP, and CBM databases were searched. All the original articles with valid HHC data among health care providers during the COVID-19 pandemic (from January 1, 2020 to October 1, 2021) were included. Meta-analysis was performed using a DerSimonian and Laird model to yield a point estimate and a 95% CI for the HHC rate. The heterogeneity of the studies was evaluated using the Cochrane Q test and I2 statistics and a random-effects model was used to contrast between different occupations, the WHO 5-moments of HH and different observation methods. Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines were followed.

FINDINGS

Seven studies with 2,377 health care providers reporting HHC were identified. The estimated overall HHC was 74%, which was higher than that reported in previous studies (5%-89%). Fever clinic has become a new key place for HHC observation. Nurses had the highest HHC (80%; 95% CI:74%-87%) while auxiliary workers (70%; 95%CI:62%-77%) had the lowest. For the WHO 5-moments, the health care providers had the highest HHC after contact with the body fluids of the patients (91%; 95% CI:88%-94%), while before contact with patient's health care providers had the lowest HHC (68%; 95% CI:62%-74%) which was consistent with before the pandemic. There existed great HHC differences among different monitoring methods (automatic monitoring system:53%; 95% CI:44%-63% versus openly and secretly observation: 91%; 95% CI: 90%-91%).

CONCLUSIONS

During the COVID-19 pandemic, the compliance of health care providers' HH showed a great improvement. The fever clinics have become the focused departments for HH monitoring. The HHC of auxiliary workers and the HH opportunity for "before contact with patients" should be strengthened. In the future, it will be necessary to develop standardized HH monitoring tools for practical work.

The impact of carbon pricing, climate financing, and financial literacy on COVID-19 cases: go-for-green healthcare policies

Climate finance and carbon pricing are regarded as sustainable policy mechanisms for mitigating negative environmental externalities via the development of green financing projects and the imposition of taxes on carbon pollution generation. Financial literacy indicates that it is beneficial to invest in cleaner technology to advance the environmental sustainability goal. The current wave of the COVID-19 epidemic has had a detrimental effect on the world economies' health and income. The pandemic crisis dwarfs previous global financial crises in terms of scope and severity, collapsing global financial markets. The study's primary contribution is constructing a climate funding index (CFI) based on four critical factors: inbound foreign direct investment, renewable energy usage, research and development spending, and carbon damages. In a cross-sectional panel of 43 nations, the research evaluates the effect of climate funding, financial literacy, and carbon pricing in lowering exposure to coronavirus cases. The study utilized Newton-Raphson and Marquardt steps to estimate the current parameter estimates while evaluating the COVID-19 prediction model with level regressors using the robust least squares regression model (S-estimator). Additionally, the innovation accounting matrix predicts estimations over a specific period. The findings indicate that climate finance significantly reduces coronavirus exposure by introducing green financing initiatives that benefit human health, which eventually strengthens the immune system's ability to fight infectious illnesses. Financial literacy and carbon pricing, on the other hand, are ineffectual in controlling coronavirus infections due to rising economic activity and densely inhabited areas that enable the transmission of coronavirus cases across countries. Similar findings were obtained using the alternative regression apparatus. The COVID-19 predicted variable was used as a "response variable," and climate financing was shown to have a favorable impact on containing coronavirus exposure. As shown by the innovation accounting matrix, carbon pricing would drastically decrease coronavirus cases' exposure over a time horizon. The study concludes that climate finance and carbon pricing were critical in improving air quality indicators, which improved countries' health and wealth, allowing them to reduce coronavirus infections via sustainable healthcare reforms.

Contamination of CT scanner surfaces with SARS-CoV-2 and infective potential after examination of invasively ventilated, non-invasively ventilated and non-ventilated patients with positive throat swabs: prospective investigation using real-time reverse-transcription PCR and viral cell culture

BACKGROUND

During the current severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) pandemic, computed tomography (CT) has become widely used in patients with suspected or known coronavirus disease 2019 (COVID-19). This prospective observational study in 28 invasively ventilated and 18 non-invasively ventilated patients with confirmed SARS-CoV-2 contamination aims at investigating SARS-CoV-2 contamination of CT scanner surfaces and its infectiousness.

METHODS

Swab sampling of the CT table and gantry before and after CT examinations was performed. Additionally, the CT ventilation system air grid was wiped off after each examination. Real-time reverse-transcription polymerase chain reaction (RT-PCR) for SARS-CoV-2 RNA (ribonucleic acid) and viral cell culture were performed in the virology core lab.

RESULTS

After examination of non-invasively ventilated or non-ventilated patients, SARS-CoV-2 RNA was found in 11.1% (4/36) on patient near surfaces (CT table and gantry) and in 16.7% (3/18) on the CT air grid respectively after examination of invasively ventilated patients in 5.4% (3/56) on CT table and gantry and 7.1% (2/28) on the CT air grid. Surface contamination was more common in non-invasively ventilated or non-ventilated patients with a high viral load who were actively coughing. RT-PCR cycle threshold (Ct) was high (35.96-39.31) in all positive samples and no positive viral cell culture was found.

CONCLUSION

Our study suggests that CT scanner surface contamination with SARS-CoV-2 is considerable and more common after examination of non-invasively ventilated or non-ventilated patients compared to invasively ventilated patients. However, no viral cell culture positivity was found, hence the infectious potential seems low.

Synthesis and assessment of copper-based nanoparticles as a surface coating agent for antiviral properties against SARS-CoV-2

To halt the pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), governments around the world have imposed policies, such as lockdowns, mandatory mask wearing, and social distancing. The application of disinfecting materials in shared public facilities can be an additional measure to control the spread of the virus. Copper is a prominent material with antibacterial and antiviral effects. In this study, we synthesized copper nanoparticles (CuNPs) as a surface coating agent and assessed their antiviral activity against SARS-CoV-2. CuNPs with a mean size of 254 nm in diameter were synthesized from copper sulfate as a source and were predominantly composed of copper oxide. The synthesized CuNPs were mixed with resin-based paint (CuNP/paint) and sprayed on the surface of stainless steel remnants. SARS-CoV-2 lost 97.8% infectivity on the CuNP/paint-coated surface after 30 min of exposure and more than 99.995% infectivity after 1 h of exposure. The inactivation rate was approximately 36-fold faster than that on the paint alone-coated and uncoated surfaces. The CuNP/paint-coated surface showed powerful inactivation of SARS-CoV-2 infectivity, although further study is needed to elucidate the inactivation mechanisms. Applications of CuNP/paint coatings to public or hospital facilities and other commonly touched areas are expected to be beneficial.

Insight into prognostics, diagnostics, and management strategies for SARS CoV-2

The foremost challenge in countering infectious diseases is the shortage of effective therapeutics. The emergence of coronavirus disease (COVID-19) outbreak has posed a great menace to the public health system globally, prompting unprecedented endeavors to contain the virus. Many countries have organized research programs for therapeutics and management development. However, the longstanding process has forced authorities to implement widespread infrastructures for detailed prognostic and diagnostics study of severe acute respiratory syndrome (SARS CoV-2). This review discussed nearly all the globally developed diagnostic methodologies reported for SARS CoV-2 detection. We have highlighted in detail the approaches for evaluating COVID-19 biomarkers along with the most employed nucleic acid- and protein-based detection methodologies and the causes of their severe downfall and rejection. As the variable variants of SARS CoV-2 came into the picture, we captured the breadth of newly integrated digital sensing prototypes comprised of plasmonic and field-effect transistor-based sensors along with commercially available food and drug administration (FDA) approved detection kits. However, more efforts are required to exploit the available resources to manufacture cheap and robust diagnostic methodologies. Likewise, the visualization and characterization tools along with the current challenges associated with waste-water surveillance, food security, contact tracing, and their role during this intense period of the pandemic have also been discussed. We expect that the integrated data will be supportive and aid in the evaluation of sensing technologies not only in current but also future pandemics.

Surface and Air Contamination With Severe Acute Respiratory Syndrome Coronavirus 2 From Hospitalized Coronavirus Disease 2019 Patients in Toronto, Canada, March-May 2020

BACKGROUND

We determined the burden of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in air and on surfaces in rooms of patients hospitalized with coronavirus disease 2019 (COVID-19) and investigated patient characteristics associated with SARS-CoV-2 environmental contamination.

METHODS

Nasopharyngeal swabs, surface, and air samples were collected from the rooms of 78 inpatients with COVID-19 at 6 acute care hospitals in Toronto from March to May 2020. Samples were tested for SARS-CoV-2 ribonucleic acid (RNA), cultured to determine potential infectivity, and whole viral genomes were sequenced. Association between patient factors and detection of SARS-CoV-2 RNA in surface samples were investigated.

RESULTS

Severe acute respiratory syndrome coronavirus 2 RNA was detected from surfaces (125 of 474 samples; 42 of 78 patients) and air (3 of 146 samples; 3 of 45 patients); 17% (6 of 36) of surface samples from 3 patients yielded viable virus. Viral sequences from nasopharyngeal and surface samples clustered by patient. Multivariable analysis indicated hypoxia at admission, polymerase chain reaction-positive nasopharyngeal swab (cycle threshold of ≤30) on or after surface sampling date, higher Charlson comorbidity score, and shorter time from onset of illness to sampling date were significantly associated with detection of SARS-CoV-2 RNA in surface samples.

CONCLUSIONS

The infrequent recovery of infectious SARS-CoV-2 virus from the environment suggests that the risk to healthcare workers from air and near-patient surfaces in acute care hospital wards is likely limited.