Contamination of inert surfaces by SARS-CoV-2: Persistence, stability and infectivity. A review

In Silico Assessment of Chemical Disinfectants on Surface Proteins Unveiled Dissimilarity in Antiviral Efficacy and Suitability towards Pathogenic Viruses

Viral pathogens pose a substantial threat to public health and necessitate the development of effective remediation and antiviral strategies. This short communication aimed to investigate the antiviral efficacy of disinfectants on the surface proteins of human pathogenic viruses. Using in silico modeling, the ligand-binding energies (LBEs) of selected disinfectants were predicted and combined with their environmental impacts and costs through an eco-pharmaco-economic analysis (EPEA). The results revealed that the binding affinities of chemical disinfectants to viral proteins varied significantly (p < 0.005). Rutin demonstrated promising broad-spectrum antiviral efficacy with an LBE of -8.49 ± 0.92 kcal/mol across all tested proteins. Additionally, rutin showed a superior eco-pharmaco-economic profile compared to the other chemicals, effectively balancing high antiviral effectiveness, moderate environmental impact, and affordability. These findings highlight rutin as a key phytochemical for use in remediating viral contaminants.

Laboratory studies on the infectivity of human respiratory viruses: Experimental conditions, detections, and resistance to the atmospheric environment

The environmental stability of infectious viruses in the laboratory setting is crucial to the transmission potential of human respiratory viruses. Different experimental techniques or conditions used in studies over the past decades have led to diverse understandings and predictions for the stability of viral infectivity in the atmospheric environment. In this paper, we review the current knowledge on the effect of simulated atmospheric conditions on the infectivity of respiratory viruses, mainly focusing on influenza viruses and coronaviruses, including severe acute respiratory syndrome coronavirus 2 and Middle East respiratory syndrome coronavirus. First, we summarize the impact of the experimental conditions on viral stability; these involve the methods of viral aerosol generation, storage during aging and collection, the virus types and strains, the suspension matrixes, the initial inoculum volumes and concentrations, and the drying process. Second, we summarize and discuss the detection methods of viral infectivity and their disadvantages. Finally, we integrate the results from the reviewed studies to obtain an overall understanding of the effects of atmospheric environmental conditions on the decay of infectious viruses, especially aerosolized viruses. Overall, this review highlights the knowledge gaps in predicting the ability of viruses to maintain infectivity during airborne transmission.

A review of the influence of environmental pollutants (microplastics, pesticides, antibiotics, air pollutants, viruses, bacteria) on animal viruses

Microorganisms, especially viruses, cause disease in both humans and animals. Environmental chemical pollutants including microplastics, pesticides, antibiotics sand air pollutants arisen from human activities affect both animal and human health. This review assesses the impact of chemical and biological contaminants (virus and bacteria) on viruses including its life cycle, survival, mutations, loads and titers, shedding, transmission, infection, re-assortment, interference, abundance, viral transfer between cells, and the susceptibility of the host to viruses. It summarizes the sources of environmental contaminants, interactions between contaminants and viruses, and methods used to mitigate such interactions. Overall, this review provides a perspective of environmentally co-occurring contaminants on animal viruses that would be useful for future research on virus-animal-human-ecosystem harmony studies to safeguard human and animal health.

Germicidal efficacy of continuous and pulsed ultraviolet-C radiation on pathogen models and SARS-CoV-2

Ultraviolet radiation's germicidal efficacy depends on several parameters, including wavelength, radiant exposure, microbial physiology, biological matrices, and surfaces. In this work, several ultraviolet radiation sources (a low-pressure mercury lamp, a KrCl excimer, and four UV LEDs) emitting continuous or pulsed irradiation were compared. The greatest log reductions in E. coli cells and B. subtilis endospores were 4.1 ± 0.2 (18 mJ cm-2) and 4.5 ± 0.1 (42 mJ cm-2) with continuous 222 nm, respectively. The highest MS2 log reduction observed was 2.7 ± 0.1 (277 nm at 3809 mJ cm-2). Log reductions of SARS-CoV-2 with continuous 222 nm and 277 nm were ≥ 3.4 ± 0.7, with 13.3 mJ cm-2 and 60 mJ cm-2, respectively. There was no statistical difference between continuous and pulsed irradiation (0.83-16.7% [222 nm and 277 nm] or 0.83-20% [280 nm] duty rates) on E. coli inactivation. Pulsed 260 nm radiation (0.5% duty rate) at 260 nm yielded significantly greater log reduction for both bacteria than continuous 260 nm radiation. There was no statistical difference in SARS-CoV-2 inactivation between continuous and pulsed 222 nm UV-C radiation and pulsed 277 nm radiation demonstrated greater germicidal efficacy than continuous 277 nm radiation. Greater radiant exposure for all radiation sources was required to inactivate MS2 bacteriophage. Findings demonstrate that pulsed irradiation could be more useful than continuous UV radiation in human-occupied spaces, but threshold limit values should be respected. Pathogen-specific sensitivities, experimental setup, and quantification methods for determining germicidal efficacy remain important factors when optimizing ultraviolet radiation for surface decontamination or other applications.

A narrative review of alternative transmission routes of COVID 19: what we know so far

The Coronavirus disease 19 (COVID-19) pandemics, caused by severe acute respiratory syndrome coronaviruses, SARS-CoV-2, represent an unprecedented public health challenge. Beside person-to-person contagion via airborne droplets and aerosol, which is the main SARS-CoV-2's route of transmission, alternative modes, including transmission via fomites, food and food packaging, have been investigated for their potential impact on SARS-CoV-2 diffusion. In this context, several studies have demonstrated the persistence of SARS-CoV-2 RNA and, in some cases, of infectious particles on exposed fomites, food and water samples, confirming their possible role as sources of contamination and transmission. Indeed, fomite-to-human transmission has been demonstrated in a few cases where person-to-person transmission had been excluded. In addition, recent studies supported the possibility of acquiring COVID-19 through the fecal-oro route; the occurrence of COVID-19 gastrointestinal infections, in the absence of respiratory symptoms, also opens the intriguing possibility that these cases could be directly related to the ingestion of contaminated food and water. Overall, most of the studies considered these alternative routes of transmission of low epidemiological relevance; however, it should be considered that they could play an important role, or even be prevalent, in settings characterized by different environmental and socio-economic conditions. In this review, we discuss the most recent findings regarding SARS-CoV-2 alternative transmission routes, with the aim to disclose what is known about their impact on COVID-19 spread and to stimulate research in this field, which could potentially have a great impact, especially in low-resource contexts.

Sampling and recovery of infectious SARS-CoV-2 from high-touch surfaces by sponge stick and macrofoam swab

Effective sampling for severe acute respiratory syndrome 2 (SARS-CoV-2) is a common approach for monitoring disinfection efficacy and effective environmental surveillance. This study evaluated sampling efficiency and limits of detection (LODs) of macrofoam swab and sponge stick sampling methods for recovering infectious SARS-CoV-2 and viral RNA (vRNA) from surfaces. Macrofoam swab and sponge stick methods were evaluated for collection of SARS-CoV-2 suspended in a soil load from 6-in2 coupons composed of four materials: stainless steel (SS), acrylonitrile butadiene styrene (ABS) plastic, bus seat fabric, and Formica. Recovery of infectious SARS-CoV-2 was more efficient than vRNA recovery on all materials except Formica (macrofoam swab sampling) and ABS (sponge stick sampling). Macrofoam swab sampling recovered significantly more vRNA from Formica than ABS and SS, and sponge stick sampling recovered significantly more vRNA from ABS than Formica and SS, suggesting that material and sampling method choice can affect surveillance results. Time since initial contamination significantly affected infectious virus recovery from all materials, with vRNA recovery showing limited to no difference, suggesting that SARS-CoV-2 vRNA can remain detectable after viral infectivity has dissipated. This study showed that a complex relationship exists between sampling method, material, time from contamination to sampling, and recovery of SARS-CoV-2. In conclusion, data show that careful consideration be used when selecting surface types for sampling and interpreting SARS-CoV-2 vRNA recovery with respect to presence of infectious virus.

Emerging infectious diseases, focus on infection prevention, environmental survival and germicide susceptibility: SARS-CoV-2, Mpox, and Candida auris

BACKGROUND

New and emerging infectious diseases continue to represent a public health threat. Emerging infectious disease threats include pathogens increasing in range (eg, Mpox), zoonotic microbes jumping species lines to cause sustained infections in humans via person-to-person transmission (SARS-CoV-2) and multidrug-resistant pathogens (eg, Candida auris).

MATERIALS AND METHODS

We searched the published English literature and reviewed the selected articles on SARS-CoV-2, Mpox, and Candida auris with a focus on environmental survival, contamination of the patient's hospital environment, susceptibility of the pathogen to antiseptics and disinfectants and infection prevention recommendations.

RESULTS

All three pathogens (ie, SARS-CoV-2, Mpox, and Candida auris) can survive on surfaces for minutes to hours and for Mpox and C auris for days. Currently available antiseptics (eg, 70%-90% alcohol hand hygiene products) are active against SARS-CoV-2, Mpox and C auris. The U.S Environmental Protection Agency provides separate lists of surface disinfectants active against SARS-CoV-2, Mpox, and C auris.

DISCUSSION

The risk of environment-to-patient transmission of SARS-CoV-2, Mpox and Candida auris, is very low, low-moderate and high, respectively. In the absence of appropriate patient isolation and use of personal protection equipment, the risk of patient-to-health care provider transmission of SARS-CoV-2, Mpox, and C auris is high, moderate and low, respectively.

CONCLUSIONS

Appropriate patient isolation, use of personal protective equipment by health care personnel, hand hygiene, and surface disinfection can protect patients and health care personnel from acquiring SARS-CoV-2, Mpox, and C auris from infected patients.

Linkage between Airborne Particulate Matter and Viral Pandemic COVID-19 in Bucharest

The long-distance spreading and transport of airborne particulate matter (PM) of biogenic or chemical compounds, which are thought to be possible carriers of SARS-CoV-2 virions, can have a negative impact on the incidence and severity of COVID-19 viral disease. Considering the total Aerosol Optical Depth at 550 nm (AOD) as an atmospheric aerosol loading variable, inhalable fine PM with a diameter ≤2.5 µm (PM2.5) or coarse PM with a diameter ≤10 µm (PM10) during 26 February 2020-31 March 2022, and COVID-19's five waves in Romania, the current study investigates the impact of outdoor PM on the COVID-19 pandemic in Bucharest city. Through descriptive statistics analysis applied to average daily time series in situ and satellite data of PM2.5, PM10, and climate parameters, this study found decreased trends of PM2.5 and PM10 concentrations of 24.58% and 18.9%, respectively compared to the pre-pandemic period (2015-2019). Exposure to high levels of PM2.5 and PM10 particles was positively correlated with COVID-19 incidence and mortality. The derived average PM2.5/PM10 ratios during the entire pandemic period are relatively low (<0.44), indicating a dominance of coarse traffic-related particles' fraction. Significant reductions of the averaged AOD levels over Bucharest were recorded during the first and third waves of COVID-19 pandemic and their associated lockdowns (~28.2% and ~16.4%, respectively) compared to pre-pandemic period (2015-2019) average AOD levels. The findings of this research are important for decision-makers implementing COVID-19 safety controls and health measures during viral infections.

There Is a Risk of Spread During a Nebulization Session in a Patient with COVID-19

Introduction: A hypothetical risk of SARS-CoV-2 airborne transmission through nebulization was suggested based on a potential environmental contamination by the fugitive aerosol emitted in the environment during the procedure. The aim of this study was to verify this risk from the fugitive aerosol emitted by COVID-19 patients during one nebulization session. Methods: In this cohort study, COVID-19 patients treated with nebulization were recruited at their admission to the hospital. Patients had to perform a nebulization session while a BioSampler® and a pump were used to vacuum the fugitive aerosol and collect it for SARS-CoV-2 RNA detection. Results: Ten consecutive patients hospitalized with COVID-19 were recruited. The median viral load was 6.5 × 106 copies/mL. Two out of the 10 samples from the fugitive aerosol collected were positive to SARS-CoV-2. Conclusion: The risk of fugitive aerosol contamination with SARS-CoV-2 during nebulization has now been verified.

Monitoring Prevalence and Persistence of Environmental Contamination by SARS-CoV-2 RNA in a Makeshift Hospital for Asymptomatic and Very Mild COVID-19 Patients

Objective: To investigate the details of environmental contamination status by SARS-CoV-2 in a makeshift COVID-19 hospital. Methods: Environmental samples were collected from a makeshift hospital. The extent of contamination was assessed by quantitative reverse transcription polymerase chain reaction (RT-qPCR) for SARS-CoV-2 RNA from various samples. Results: There was a wide range of total collected samples contaminated with SARS-CoV-2 RNA, ranging from 8.47% to 100%. Results revealed that 70.00% of sewage from the bathroom and 48.19% of air samples were positive. The highest rate of contamination was found from the no-touch surfaces (73.07%) and the lowest from frequently touched surfaces (33.40%). The most contaminated objects were the top surfaces of patient cubic partitions (100%). The median Ct values among strongly positive samples were 33.38 (IQR, 31.69-35.07) and 33.24 (IQR, 31.33-34.34) for ORF1ab and N genes, respectively. SARS-CoV-2 relic RNA can be detected on indoor surfaces for up to 20 days. Conclusion: The findings show a higher prevalence and persistence in detecting the presence of SARS-CoV-2 in the makeshift COVID-19 hospital setting. The contamination mode of droplet deposition may be more common than contaminated touches.

Porcine Epidemic Diarrhea Virus, Surrogate for Coronavirus Decay Measurement in French Coastal Waters and Contribution to Coronavirus Risk Evaluation

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in infected patients mainly displays pulmonary and oronasal tropism; however, the presence of the virus has also been demonstrated in the stools of patients and consequently in wastewater treatment plant effluents, raising the question of the potential risk of environmental contamination (such as seawater contamination) through inadequately treated wastewater spillover into surface or coastal waters even if the environmental detection of viral RNA alone does not substantiate risk of infection. Therefore, here, we decided to experimentally evaluate the persistence of the porcine epidemic diarrhea virus (PEDv), considered as a coronavirus representative model, in the coastal environment of France. Coastal seawater was collected, sterile-filtered, and inoculated with PEDv before incubation for 0 to 4 weeks at four temperatures representative of those measured along the French coasts throughout the year (4, 8, 15, and 24°C). The decay rate of PEDv was determined using mathematical modeling and was used to determine the half-life of the virus along the French coast in accordance with temperatures from 2000 to 2021. We experimentally observed an inverse correlation between seawater temperature and the persistence of infectious viruses in seawater and confirm that the risk of transmission of infectious viruses from contaminated stool in wastewater to seawater during recreational practices is very limited. The present work represents a good model to assess the persistence of coronaviruses in coastal environments and contributes to risk evaluation, not only for SARS-CoV-2 persistence, but also for other coronaviruses, specifically enteric coronaviruses from livestock. IMPORTANCE The present work addresses the question of the persistence of coronavirus in marine environments because SARS-CoV-2 is regularly detected in wastewater treatment plants, and the coastal environment, subjected to increasing anthropogenic pressure and the final receiver of surface waters and sometimes insufficiently depurated wastewater, is particularly at risk. The problem also arises in the possibility of soil contamination by CoV from animals, especially livestock, during manure application, where, by soil impregnation and runoff, these viruses can end up in seawater. Our findings are of interest to researchers and authorities seeking to monitor coronaviruses in the environment, either in tourist areas or in regions of the world where centralized systems for wastewater treatment are not implemented, and more broadly, to the scientific community involved in "One Health" approaches.

Impact of a Serious Game (#RedPingüiNO) to Reduce Facial Self-Touches and Prevent Exposure to Pathogens Transmitted via Hands: Quasi-Experimental Intervention

BACKGROUND

After the COVID-19 pandemic, society has become more aware of the importance of some basic hygienic habits to avoid exposure to pathogens transmitted via hands. Given that a high frequency of touching mucous membranes can lead to a high risk of infection, it is essential to establish strategies to reduce this behavior as a preventive measure against contagion. This risk can be extrapolated to a multitude of health scenarios and transmission of many infectious diseases. #RedPingüiNO was designed as an intervention to prevent the transmission of SARS-CoV-2 and other pathogens through the reduction of facial self-touches by thoughtfully engaging participants in a serious game.

OBJECTIVE

Facial self-touches should be understood as behaviors of limited control and awareness, used to regulate situations of cognitive and emotional demands, or as part of nonverbal communication. The objective of this study was to ensure that participants become aware of and reduce these behaviors through a game of self-perception.

METHODS

The quasi-experimental intervention was applied to 103 healthy university students selected by convenience sampling and put into practice for 2 weeks, with 1 control group (n=24, 23.3%) and 2 experimental groups (experimental group with no additional social reinforcement interventions: n=36, 35%; experimental group with additional social reinforcement interventions: n=43, 41.7%). The objective was to improve knowledge and perception and reduce facial self-touches to prevent exposure to pathogens transmitted via hands not only in health multihazard scenarios but also in ordinary circumstances. The ad hoc instrument used to analyze the experience consisted of 43 items and was valid and reliable for the purpose of this study. The items were divided into 5 blocks extracted from the theoretical framework: sociological issues (1-5); hygiene habits (6-13); risk awareness (14-19); strategies for not touching the face (20-26); and questions after the intervention (27-42), designed as a postintervention tool assessing the game experience. Validation of the content was achieved through assessment by 12 expert referees. External validation was performed using a test-retest procedure, and reliability was verified using the Spearman correlation.

RESULTS

The results of the ad hoc questionnaire, which were analyzed using the Wilcoxon signed-rank test and McNemar index to identify significant differences between test and retest for a 95% CI, showed that facial self-touches were reduced (item 20, P<.001; item 26, P=.04), and awareness of this spontaneous behavior and its triggers increased (item 15; P=.007). The results were reinforced by qualitative findings from the daily logs.

CONCLUSIONS

The intervention exhibited a greater effect from sharing the game, with interactions between people; however, in both cases, it was helpful in reducing facial self-touches. In summary, this game is suitable for reducing facial self-touches, and owing to its free availability and design, it can be adapted to various contexts.

SARS-CoV-2 Surveillance between 2020 and 2021 of All Mammalian Species in Two Flemish Zoos (Antwerp Zoo and Planckendael Zoo)

The COVID-19 pandemic has led to millions of human infections and deaths worldwide. Several other mammal species are also susceptible to SARS-CoV-2, and multiple instances of transmission from humans to pets, farmed mink, wildlife and zoo animals have been recorded. We conducted a systematic surveillance of SARS-CoV-2 in all mammal species in two zoos in Belgium between September and December 2020 and July 2021, in four sessions, and a targeted surveillance of selected mammal enclosures following SARS-CoV-2 infection in hippopotamuses in December 2021. A total of 1523 faecal samples from 103 mammal species were tested for SARS-CoV-2 via real-time PCR. None of the samples tested positive for SARS-CoV-2. Additional surrogate virus neutralisation tests conducted on 50 routinely collected serum samples from 26 mammal species were all negative. This study is the first to our knowledge to conduct active SARS-CoV-2 surveillance for several months in all mammal species of a zoo. We conclude that at the time of our investigation, none of the screened animals were excreting SARS-CoV-2.

The Coronavirus Calendar (CoronaCal): a simplified SARS-CoV-2 test system for sampling and retrospective analysis

Objectives

To develop a biological diary (CoronaCal) that allows anyone in the community to collect and store serial saliva samples and chart symptoms on ordinary printer paper.

Methods

Diaries were analyzed for the presence of SARS-CoV-2 RNA using established polymerase chain reaction (PCR) procedures. CoronaCal diaries were distributed to volunteer subjects in the community during the peak of the COVID-19 outbreak in New York. Volunteers collected their own daily saliva samples and self-reported symptoms.

Results

SARS-CoV-2 RNA extracted from CoronaCals was measured using qPCR and RNA levels were correlated with reported symptoms. SARS-CoV-2 RNA was detected in CoronaCals from nine of nine people with COVID-19 symptoms or exposure to someone with COVID-19, and not in one asymptomatic person. CoronaCals were stored for up to 70 days at room temperature during collection and then frozen for up to four months before analysis, suggesting that SARS-CoV-2 RNA is stable once dried onto paper.

Conclusions

Sampling saliva on simple paper provides a useful method to study the natural history and epidemiology of COVID-19. The CoronaCal collection and testing method is easy to implement, inexpensive, non-invasive and scalable. The approach can inform the historical and epidemiological understanding of infections in individuals and populations.

Determining half-life of SARS-CoV-2 antigen in respiratory secretion

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is primarily transmitted from person to person through respiratory droplets and aerosols. It is also possible for the virus to be transmitted indirectly through environmental contamination. The likelihood of environmental transmission depends on several factors, including the survival time of the virus in respiratory secretions. However, the stability of SARS-CoV-2 in respiratory secretions has not been investigated. In this study, we compared the half-life of the SARS-CoV-2 antigen in respiratory secretion under different conditions. We applied respiratory secretion (5 µL) to glass slides, air-dried the slides for 1 h, and kept them at 24 °C or 4 °C for 10 days. Respiratory secretions were also placed in test tubes (sealed to preserve moisture) and in normal saline for 10 days. The concentration of SARS-CoV-2 antigen in all samples was simultaneously measured using colloidal gold immunochromatography, and the half-life of the antigen was calculated. The half-life of the antigen in the wet (sealed tube) and saline samples at room temperature was 5.0 and 2.92 days, respectively. The half-life of the antigen in the air-dried sample at room temperature and at 4 °C was 2.93 and 11.4 days, respectively. The half-life was longer in respiratory secretions than that in normal saline. The half-life was also longer in respiratory secretions, at a lower temperature, and under wet conditions. Therefore, environmental transmission can also play a significant role in the spread of the virus. Robust prevention and control strategies could be developed based on the half-life of the antigen in respiratory secretions.

Peculiar weather patterns effects on air pollution and COVID-19 spread in Tokyo metropolis

As a pandemic hotspot in Japan, between March 1, 2020-October 1, 2022, Tokyo metropolis experienced seven COVID-19 waves. Motivated by the high rate of COVID-19 incidence and mortality during the seventh wave, and environmental/health challenges we conducted a time-series analysis to investigate the long-term interaction of air quality and climate variability with viral pandemic in Tokyo. Through daily time series geospatial and observational air pollution/climate data, and COVID-19 incidence and death cases, this study compared the environmental conditions during COVID-19 multiwaves. In spite of five State of Emergency (SOEs) restrictions associated with COVID-19 pandemic, during (2020-2022) period air quality recorded low improvements relative to (2015-2019) average annual values, namely: Aerosol Optical Depth increased by 9.13% in 2020 year, and declined by 6.64% in 2021, and 12.03% in 2022; particulate matter PM2.5 and PM10 decreased during 2020, 2021, and 2022 years by 10.22%, 62.26%, 0.39%, and respectively by 4.42%, 3.95%, 5.76%. For (2021-2022) period the average ratio of PM2.5/PM10 was (0.319 ± 0.1640), showing a higher contribution to aerosol loading of traffic-related coarse particles in comparison with fine particles. The highest rates of the daily recorded COVID-19 incidence and death cases in Tokyo during the seventh COVID-19 wave (1 July 2022-1 October 2022) may be attributed to accumulation near the ground of high levels of air pollutants and viral pathogens due to: 1) peculiar persistent atmospheric anticyclonic circulation with strong positive anomalies of geopotential height at 500 hPa; 2) lower levels of Planetary Boundary Layer (PBL) heights; 3) high daily maximum air temperature and land surface temperature due to the prolonged heat waves (HWs) in summer 2022; 4) no imposed restrictions. Such findings can guide public decision-makers to design proper strategies to curb pandemics under persistent stable anticyclonic weather conditions and summer HWs in large metropolitan areas.

A Comprehensive Sampling Study on SARS-CoV-2 Contamination of Air and Surfaces in a Large Meat Processing Plant Experiencing COVID-19 Clusters in June 2020

OBJECTIVE

We aimed to assess SARS-CoV-2 contamination of air and surfaces to gain insight into potential occupational exposure in a large meat processing plant experiencing COVID-19 clusters. Methods: Oro-nasopharyngeal SARS-CoV-2 screening was performed in 76 workers. Environmental samples ( n = 275) including air, ventilation systems, sewage, and swabs of high-touch surfaces and workers' hands were tested for SARS-CoV-2 RNA by real-time quantitative polymerase chain reaction. Results: Twenty-seven (35.5%) of the (predominantly asymptomatic) workers tested positive with modest to low viral loads (cycle threshold ≥ 29.7). Six of 203 surface swabs, 1 of 12 personal air samples, and one of four sewage samples tested positive; other samples tested negative. Conclusions: Although one third of workers tested positive, environmental contamination was limited. Widespread SARS-CoV-2 transmission via air and surfaces was considered unlikely within this plant at the time of investigation while strict COVID-19 control measures were already implemented.

Shaping the subway microbiome through probiotic-based sanitation during the COVID-19 emergency: a pre-post case-control study

BACKGROUND

The COVID-19 pandemic has highlighted the extent to which the public transportation environment, such as in subways, may be important for the transmission of potential pathogenic microbes among humans, with the possibility of rapidly impacting large numbers of people. For these reasons, sanitation procedures, including massive use of chemical disinfection, were mandatorily introduced during the emergency and remain in place. However, most chemical disinfectants have temporary action and a high environmental impact, potentially enhancing antimicrobial resistance (AMR) of the treated microbes. By contrast, a biological and eco-sustainable probiotic-based sanitation (PBS) procedure was recently shown to stably shape the microbiome of treated environments, providing effective and long-term control of pathogens and AMR spread in addition to activity against SARS-CoV-2, the causative agent of COVID-19. Our study aims to assess the applicability and impact of PBS compared with chemical disinfectants based on their effects on the surface microbiome of a subway environment.

RESULTS

The train microbiome was characterized by both culture-based and culture-independent molecular methods, including 16S rRNA NGS and real-time qPCR microarray, for profiling the train bacteriome and its resistome and to identify and quantify specific human pathogens. SARS-CoV-2 presence was also assessed in parallel using digital droplet PCR. The results showed a clear and significant decrease in bacterial and fungal pathogens (p < 0.001) as well as of SARS-CoV-2 presence (p < 0.01), in the PBS-treated train compared with the chemically disinfected control train. In addition, NGS profiling evidenced diverse clusters in the population of air vs. surface while demonstrating the specific action of PBS against pathogens rather than the entire train bacteriome.

CONCLUSIONS

The data presented here provide the first direct assessment of the impact of different sanitation procedures on the subway microbiome, allowing a better understanding of its composition and dynamics and showing that a biological sanitation approach may be highly effective in counteracting pathogens and AMR spread in our increasingly urbanized and interconnected environment. Video Abstract.

PVC containing silver nanoparticles with antimicrobial properties effective against SARS-CoV-2

Poly (vinyl chloride) (PVC) is commonly used to manufacture biomedical devices and hospital components, but it does not present antimicrobial activity enough to prevent biofouling. With the emergence of new microorganisms and viruses, such as Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) that was responsible for the global pandemic caused by Coronavirus Disease 2019 (COVID-19), it is evident the importance of the development of self-disinfectant PVC for hospital environments and medical clinics where infected people remain for a long time. In this contribution, PVC nanocomposites with silver nanoparticles (AgNPs) were prepared in the molten state. AgNPs are well-known as antimicrobial agents suitable for designing antimicrobial polymer nanocomposites. Adding 0.1 to 0.5 wt% AgNPs significantly reduced Young’s modulus and ultimate tensile strength of PVC due to the emergence of microstructural defects in the PVC/AgNP nanocomposites, but the impact strength did not change significantly. Furthermore, nanocomposites have a higher yellowness index (YI) and lower optical bandgap values than PVC. The PVC/AgNP nanocomposites present virucidal activity against SARS-CoV-2 (B.1.1.28 strain) within 48 h when the AgNP content is at least 0.3 wt%, suitable for manufacturing furniture and hospital equipment with self-disinfectant capacity to avoid secondary routes of COVID-19 contagion.

Surface Contamination of Reusable Respirators and Face Shields During Care of Critically Ill COVID-19 Patients

BACKGROUND

With the emergence of SARS-CoV-2, healthcare workers (HCW) have relied on reusable personal protective equipment (PPE), including respirators and face shields (FSs). The effectiveness of decontamination procedures outside experimental settings is unclear. We examined the prevalence of surface contamination on reusable PPE used by HCWs at a hospital incorporating daily centralized decontamination and post-use wiping by sampling for common pathogens.

METHOD

Samples were collected from HCWs' CleanSpace Halo respirator face masks (FMs) and FSs at the start of shift, immediately after use, and after cleaning with disinfecting wipes. Samples were analyzed for pathogens using the Applied Biosystems™ TaqPath™ COVID-19 Combo Kit and ThermoFisher TaqMan Array Card. Patient charts were reviewed for clinical correlation.

FINDINGS

Of the 89 samples, 51 from FMs and 38 from FSs, none tested positive for SARS-CoV-2, despite 58 being obtained from PPE used in the care of patients with COVID-19, many with recent aerosol-generating procedures. Four samples tested positive (4.5%) for Staphylococcus aureus, two each from FMs and FSs. FMs that tested positive were not worn concurrently with FSs that tested positive. The FM and FS samples testing positive were worn in the care of patients without diagnosed S. aureus infection. No FMs tested positive following wipe-based disinfection, but both positive FS samples were found after disinfection wiping.

CONCLUSION/APPLICATION TO PRACTICE

Contamination of reusable PPE appears uncommon, especially with SARS-CoV-2, when regular decontamination programs are in place. The rare presence of S. aureus highlights the importance of doffing procedures and hand hygiene by HCW to prevent surface contamination.

Evaluation of Viral Inactivation on Dry Surface by High Peak Power Microwave (HPPM) Exposure

Previous research has shown that virus infectivity can be dramatically reduced by radio frequency exposure in the gigahertz (GHz) frequency range. Given the worldwide SARS-CoV-2 pandemic, which has caused over 1 million deaths and has had a profound global economic impact, there is a need for a noninvasive technology that can reduce the transmission of virus among humans. RF is a potential wide area-of-effect viral decontamination technology that could be used in hospital rooms where patients are expelling virus, in grocery and convenience stores where local populations mix, and in first responder settings where rapid medical response spans many potentially infected locations within hours. In this study, we used bovine coronavirus (BCoV) as a surrogate of SARS-CoV-2 and exposed it to high peak power microwave (HPPM) pulses at four narrowband frequencies: 2.8, 5.6, 8.5, and 9.3 GHz. Exposures consisted of 2 µs pulses delivered at 500 Hz, with pulse counts varied by decades between 1 and 10,000. The peak field intensities (i.e. the instantaneous power density of each pulse) ranged between 0.6 and 6.5 MW/m² , depending on the microwave frequency. The HPPM exposures were delivered to plastic coverslips containing BCoV dried on the surface. Hemagglutination (HA) and cytopathic effect analyses were performed 6 days after inoculation of host cells to assess viral infectivity. No change in viral infectivity was seen with increasing dose (pulse number) across the tested frequencies. Under all conditions tested, exposure did not reduce infectivity more than 1.0 log_10. For the conditions studied, high peak power pulsed RF exposures in the 2-10 GHz range appear ineffective as a virucidal approach for hard surface decontamination. © 2023 Bioelectromagnetics Society.

Strategies for safe management of hospital wastewater during the COVID-19 pandemic

Management of hospital wastewater is a challenging task, particularly during the situations like coronavirus 2019 (COVID-19) pandemic. The hospital effluent streams are likely to contain many known and unknown contaminants including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) along with a variety of pollutants arising from pharmaceuticals, life-style chemicals, drugs, radioactive species, and human excreta from the patients. The effluents are a mixed bag of contaminants with some of them capable of infecting through contact. Hence, it is essential to identify appropriate treatment strategies for hospital waste streams. In this work, various pollutants emerging in the context of COVID-19 are examined. A methodical review is conducted on the occurrence and disinfection methods of SARS-CoV-2 in wastewater. An emphasis is given to the necessity of addressing the challenges of handling hospital effluents dynamically involved during the pandemic scenario to ensure human and environmental safety. A comparative evaluation of disinfection strategies makes it evident that the non-contact methods like ultraviolet irradiation, hydrogen peroxide vapor, and preventive approaches such as the usage of antimicrobial surface coating offer promise in reducing the chance of disease transmission. These methods are also highly efficient in comparison with other strategies. Chemical disinfection strategies such as chlorination may lead to further disinfection byproducts, complicating the treatment processes. An overall analysis of various disinfection methods is presented here, including developing methods such as membrane technologies, highlighting the merits and demerits of each of these processes. Finally, the wastewater surveillance adopted during the COVID-19 outbreak is discussed.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13762-023-04803-1.

Clinical Significance and Diagnostic Utility of NLR, LMR, PLR and SII in the Course of COVID-19: A Literature Review

Nowadays, society is increasingly struggling with infectious diseases that are characterized by severe course and even death. Recently, the whole world has faced the greatest epidemiological threat, which is COVID-19 caused by SARS CoV-2 virus. SARS CoV-2 infection is often accompanied by severe inflammation, which can lead to the development of different complications. Consequently, clinicians need easily interpreted and effective markers of inflammation that can predict the efficacy of the treatment and patient prognosis. Inflammation is associated with changes in many biochemical and hematological parameters, including leukocyte counts and their populations. In COVID-19, changes in leukocytes count populations such as neutrophils, lymphocytes or monocytes are observed. The numerous research confirm that indicators like neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), platelets-to-lymphocyte ratio (PLR) and systemic inflammatory index (SII) may prove effective in assessment patient prognosis and choosing optimal therapy. Therefore, in this review, we would like to summarize the latest knowledge about the diagnostic utility of systemic inflammatory ratios - NLR, LMR, PLR and SII in patients with COVID-19. We focused on the papers evaluating the diagnostic utility of inflammatory ratios using ROC curve published in the recent 3 years. Identification of biomarkers associated with inflammation would help the selection of patients with severe course of COVID-19 and high risk of death.

Psychological factors and oral health during initial outbreak of COVID-19 in China: A cross-sectional study

OBJECTIVES

To investigate associations between oral health and psychological factors (i.e., depression, anxiety, and resilience) in a group of Chinese individuals who had sought an intervention online during the COVID-19 pandemic.

METHODS

For this cross-sectional study, online questionnaires were created using online survey software from set items of instruments commonly used to assess depression, anxiety, and resilience combined with an oral health survey. The study was conducted from March 13 to 16, 2020.

RESULTS

568 participants (188 men and 380 women) with a mean ± SD age of 41.7 ± 10.2 years were included in the analyses. In total, 152 (27%) participants were from Beijing, 149 (26%) from Wuhan, 110 (19%) from Shenyang, and 157 (28%) from other Chinese cities. Halitosis and bleeding gums were the most common reasons for individuals to seek an intervention. Compared with other cities, participants from Wuhan showed higher anxiety and depression and worse previous oral health. Resilience mediated the relationship between depression and oral health, but not between anxiety and oral health.

CONCLUSION

We hope that the data from this study will inform clinical practitioners and demonstrate that mental health awareness and resilience training are important strategies that may mitigate the negative impact of lockdown and isolation on oral health.

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.

COVID-19 infection rates and mitigation strategies in orthodontic practices

BACKGROUND

COVID-19 has impacted and increased risks for all populations, including orthodontic patients and providers. It also changes the practice management and infection control landscape in the practices. This study aimed to investigate the COVID-19 infection and vaccination status of orthodontic providers and mitigation approaches in orthodontic practices in the United States during 2021.

METHODS

A validated 50-question research electronic data capture (REDCap) browser-based questionnaire was distributed to 12,393 orthodontists and pediatric dentists who reported actively providing orthodontic treatment. Questions were designed to collect demographic data of respondents, evaluate the COVID-19 mitigation approaches, and evaluate the history of COVID-19 infection and vaccination status of the orthodontic providers. Associations of demographic and the COVID-19 mitigation approaches were assessed using chi-square tests at the significance level of 0.05.

RESULTS

Four hundred fifty-seven returned the survey (response rate 3.69%) for analysis. Most respondents were vaccinated, and increased infection control measures in response to the pandemic. Half of the respondents practiced teledentistry and switched to digital impression systems. Two-thirds reported difficulties in attaining PPEs due to the increased cost and scarcity of PPEs. About 6% of respondents reported a history of COVID-19 infection, and 68.9% of their staff had COVID-19 infection. Statistically significant associations were found between increased practice experience with difficulties in acquiring PPE (p = .010). There were no significant associations between races of respondents, geographic location, and years of practicing when cross-tabulated with vaccination status or COVID-19 infection rate (p > .05).

CONCLUSION

Increased infection control strategies were employed in almost all orthodontic practices in addition to existing universal precaution. Most of the orthodontic providers and their staff members were vaccinated. While staff's infection rates were an issue, doctors' infection rates remained low.

Various advanced wastewater treatment methods to remove microplastics and prevent transmission of SARS-CoV-2 to airborne microplastics

Microplastics (MPs) and SARS-CoV-2 interact due to their widespread presence in our environment and affect the virus' behaviour indoors and outdoors. Therefore, it is necessary to study the interaction between MPs and SARS-CoV-2. The environmental damage caused by MPs is increasing globally. Emerging pollutants may adversely affect organisms, especially sewage, posing a threat to human health, animal health, and the ecological system. A significant concern with MPs in the air is that they are a vital component of MPs in the other environmental compartments, such as water and soil, which may affect human health through ingesting or inhaling. This work introduces the fundamental knowledge of various methods in advanced water treatment, including membrane bioreactors, advanced oxidation processes, adsorption, etc., are highly effective in removing MPs; they can still serve as an entrance route due to their constantly being discharged into aquatic environments. Following that, an analysis of each process for MPs' removal and mitigation or prevention of SARS-CoV-2 contamination is discussed. Next, an airborne microplastic has been reported in urban areas, raising health concerns since aerosols are considered a possible route of SARS-CoV-2 disease transmission and bind to airborne MP surfaces. The MPs can be removed from wastewater through conventional treatment processes with physical processes such as screening, grit chambers, and pre-sedimentation.

In vitro infection of human ocular tissues by SARS-CoV-2 lineage A isolates

BACKGROUND

The purpose of this study was: [1] to evaluate the infectivity of two SARS-CoV-2 lineage A variants on human ocular tissues in vitro, and [2] to evaluate the stability of SARS-CoV-2 lineage A variants in corneal preservation medium.

METHODS

Primary cultures of donor corneal, conjunctival, and limbal epithelium were inoculated with two lineage A, GISAID clade S isolates of SARS-CoV-2 (Hong Kong/VM20001061/2020, USA-WA1/2020), to evaluate the susceptibility of the ocular tissue to infection. Flat-mounted Descemet's Stripping Automated Endothelial Keratoplasty (DSAEK) grafts were inoculated with SARS-CoV-2 to evaluate the susceptibility of the endothelium to infection. All inoculated samples were immunostained for SARS-CoV-2 nucleocapsid (N)-protein expression to confirm positive infection. SARS-CoV-2 Hong Kong was then inoculated into cornea preservation media (Life4°C, Numedis, Inc.). Inoculated media was stored at 4^oC for 14 days and assayed over time for changes in infectious viral titers.

RESULTS

Corneal, conjunctival, and limbal epithelial cells all demonstrated susceptibility to infection by SARS-CoV-2 lineage A variants. Conjunctiva demonstrated the highest infection rate (78% of samples infected [14/18]); however, infection rates did not differ statistically between cell types and viral isolates. After inoculation, 40% (4/10) of DSAEK grafts had active infection in the endothelium. SARS-CoV-2 lineage A demonstrated < 1 log decline in viral titers out to 14 days in corneal preservation media.

CONCLUSIONS

SARS-CoV-2 lineage A variants can infect corneal, limbal, and conjunctival epithelium, as well as corneal endothelium. There was no statistical difference in infectivity between different lineage A variants. SARS-CoV-2 lineage A can survive and remain infectious in corneal preservation media out to 14 days in cold storage.

Survival and detection of SARS-CoV-2 variants on dry swabs post storage

COVID-19 has resulted in nearly 598 million infections and over 6.46 million deaths since the start of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic in 2019. The rapid onset of the pandemic, combined with the emergence of viral variants, crippled many health systems particularly from the perspective of coping with massive diagnostic loads. Shortages of diagnostic kits and capacity forced laboratories to store clinical samples resulting in huge backlogs, the effects of this on diagnostic pickup have not been fully understood. Herein, we investigated the impact of storing SARS-CoV-2 inoculated dry swabs on the detection and viability of four viral strains over a period of 7 days. Viral load, as detected by qRT-PCR, displayed no significant degradation during this time for all viral loads tested. In contrast, there was a ca. 2 log reduction in viral viability as measured by the tissue culture infectious dose (TCID) assay, with 1-3 log viable virus detected on dry swabs after 7 days. When swabs were coated with 10² viral copies of the Omicron variant, no viable virus was detected after 24 hours following storage at 4°C or room temperature. However there was no loss of PCR signal over 7 days. All four strains showed comparable growth kinetics and survival when cultured in Vero E6 cells. Our data provide information on the viability of SARS-CoV-2 on stored swabs in a clinical setting with important implications for diagnostic pickup and laboratory processing protocols. Survival after 7 days of SARS-CoV-2 strains on swabs with high viral loads may impact public health and biosafety practices in diagnostic laboratories.

Indirect Virus Transmission via Fomites Can Counteract Lock-Down Effectiveness

The spread of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) has raised major health policy questions. Direct transmission via respiratory droplets seems to be the dominant route of its transmission. However, indirect transmission via shared contact of contaminated objects may also occur. The contribution of each transmission route to epidemic spread might change during lock-down scenarios. Here, we simulate viral spread of an abstract epidemic considering both routes of transmission by use of a stochastic, agent-based SEIR model. We show that efficient contact tracing (CT) at a high level of incidence can stabilize daily cases independently of the transmission route long before effects of herd immunity become relevant. CT efficacy depends on the fraction of cases that do not show symptoms. Combining CT with lock-down scenarios that reduce agent mobility lowers the incidence for exclusive direct transmission scenarios and can even eradicate the epidemic. However, even for small fractions of indirect transmission, such lockdowns can impede CT efficacy and increase case numbers. These counterproductive effects can be reduced by applying measures that favor distancing over reduced mobility. In summary, we show that the efficacy of lock-downs depends on the transmission route. Our results point to the particular importance of hygiene measures during mobility lock-downs.

Aging of colloidal contaminants and pathogens in the soil environment: Implications for nanoplastic and COVID-19 risk mitigation

Colloidal contaminants and pathogens are widely distributed in soil, whose tiny sizes and distinct surface properties render unique environmental behaviours. Because of aging, colloids can undergo dramatic changes in their physicochemical properties once in the soil environment, thus leading to diverse or even unpredictable environmental behaviour and fate. Herein, we provide a state-of-art review of colloid aging mechanisms and characteristics and implications for risk mitigation. First, we review aging-induced formation of colloidal contaminants and aging-associated changes. We place a special focus on emerging nanoplastic (NP) contaminants and associated physical, chemical, and biological aging processes in soil environments. Second, we assess aging and survival features of colloidal pathogens, especially viruses. Viruses in soils may survive from several days to months, or even several years in groundwater, depending on their rates of inactivation and the reversibility of attachment. Furthermore, we identify implications for risk mitigation based on aging mechanisms. Hotspots of (photo)chemical aging of NPs, including plastic gauzes at construction sites and randomly discarded plastic waste in rural areas, are identified as area requiring greater research attention. For COVID-19, we suggest taking greater care in regions where viruses are persist for long periods, such as cold climate regions. Soil amendment with quicklime (CaO) may act as an effective means for pathogen disinfection. Future risk mitigation of colloidal contaminants and pathogens relies on a better understanding of aging mechanisms and more sophisticated models accurately depicting processes in real soil environments.

SARS-CoV-2 Contamination of Ambulance Surfaces and Effectiveness of Routine Decontamination Procedure: A Classic Hygiene Lesson for A Novel Pathogen

The efficacy of standard operating procedures (SOPs) for the decontamination of ambulances against SARS-CoV-2 has been debated. In Italy, the differential use of ambulances was implemented by regional health authorities, with selected vehicles being used exclusively for transporting COVID-19 patients. We investigated the presence of SARS-CoV-2 on high-touch surfaces in ambulances to assess contamination dynamics and the effectiveness of decontamination SOPs. Four high-touch surfaces were sampled before and after decontamination (T0; T1). The gloves of the EMS crew chief were also sampled. RNA extraction was performed with a commercial kit, followed by RT-qPCR molecular detection of SARS-CoV-2. A total of 11 transports were considered. Seven transports had at least one positive sample; all were related to a COVID-19 patient. Three of the negative transports had dealt with COVID-19 case, and one had dealt with a COVID-19-negative patient. One door handle and one oxygen knob were positive at T0, with negative T1 swabs. The monitors were positive in 5 transports at T0, yet they were never positive at T1. Three stretcher handles tested positive at T0, and two of them also at T1, possibly having bypassed decontamination during personnel dismounting. Gloves were contaminated in five transports, in which 1 to 3 additional samples (monitor, knob, stretcher) resulted as positive. Overall, the efficacy of decontamination SOPs was confirmed under the unprecedented conditions of the COVID-19 emergency. However, the importance of correct hand-hygiene and glove-disposal should be further emphasized through the dedicated training of EMS personnel.

An Advanced Tape-Stripping Approach for High-Efficiency Sampling on Non-Absorbent Surfaces

Surface sampling is a frequent task in laboratory work and field studies. Simple methods usually have low efficiency in collecting target substances from surfaces. This study developed an advanced tape-stripping approach for efficient sampling on non-absorbent surfaces. A film-forming solution, prepared using polyvinyl alcohol, is applied to the target surface, where it covers and engulfs the surface deposits and then solidifies into an elastic membrane as it is exposed to air. The deposits are collected by stripping off the membrane and re-dissolving it in water. This new approach exhibited an efficiency of 100% in collecting uniform-size microspheres from glass surfaces and extremely high efficiencies (>96.6%) in detecting selected target DNA materials from glass and stainless steel surfaces. In comparison, the common swab-rinse method exhibited an efficiency of 72.6% under similar measuring conditions. The viability of S. aureus during sampling using the new approach decreased as the ethanol concentration in the applied solution increased. Using a solution with a mass ratio of ethanol of 17.6% balanced the effects of multiplication and degradation of the S. aureus on glass surfaces during sampling. Overall, the proposed approach exhibits high efficiency in collecting living and abiotic matter from non-absorbent surfaces, complementing existing sampling methods.

Understanding and combating COVID-19 using the biology and chemistry of SARS-CoV-2

The coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Symptoms of COVID-19 can range from asymptomatic to severe, which could lead to fatality. Like other pathogenic viruses, the infection of SARS-CoV-2 relies on binding its spike glycoprotein to the host receptor angiotensin-converting enzyme 2 (ACE 2). Molecular studies suggested that there is a high affinity between the spike glycoprotein and ACE 2 that might arise due to their hydrophobic interaction. This property is mainly responsible for making this virus highly infectious. Apart from this, the transmissibility of the virus, prolonged viability in certain circumstances, and rapid mutations also contributed to the current pandemic situation. Nanotechnology provides potential alternative solutions to combat COVID-19 with the development of i. nanomaterial-based COVID-19 detection technology, ii. nanomaterial-based disinfectants, iii. nanoparticle-based vaccines, and iv. nanoparticle-based drug delivery. Hence, this review provides diverse insight into understanding COVID-19.

Consideration of COVID-19 beyond the human-centred approach of prevention and control: the ONE-HEALTH perspective

Most of the new emerging and re-emerging zoonotic virus outbreaks in recent years stem from close interaction with dead or alive infected animals. Since late 2019, the coronavirus disease 2019 (COVID-19) has spread into 221 countries and territories resulting in close to 300 million known infections and 5.4 million deaths in addition to a huge impact on both public health and the world economy. This paper reviews the COVID-19 prevalence in animals, raise concerns about animal welfare and discusses the role of environment in the transmission of COVID-19. Attention is drawn to the One Health concept as it emphasizes the environment in connection with the risk of transmission and establishment of diseases shared between animals and humans. Considering the importance of One Health for an effective response to the dissemination of infections of pandemic character, some unsettled issues with respect to COVID-19 are highlighted.

Two Years into the COVID-19 Pandemic: Lessons Learned

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly transmissible and virulent human-infecting coronavirus that emerged in late December 2019 in Wuhan, China, causing a respiratory disease called coronavirus disease 2019 (COVID-19), which has massively impacted global public health and caused widespread disruption to daily life. The crisis caused by COVID-19 has mobilized scientists and public health authorities across the world to rapidly improve our knowledge about this devastating disease, shedding light on its management and control, and spawned the development of new countermeasures. Here we provide an overview of the state of the art of knowledge gained in the last 2 years about the virus and COVID-19, including its origin and natural reservoir hosts, viral etiology, epidemiology, modes of transmission, clinical manifestations, pathophysiology, diagnosis, treatment, prevention, emerging variants, and vaccines, highlighting important differences from previously known highly pathogenic coronaviruses. We also discuss selected key discoveries from each topic and underline the gaps of knowledge for future investigations.

Potential risk of SARS-CoV-2 infection among people handling linens used by COVID-19 patients before and after washing

The risk of SARS-CoV-2 infection when people handle linens is uncertain. We examined the presence of SARS-CoV-2 on linens, in the air, and on personal protective equipment (PPE) to assess potential infection risk among individuals who handle linens used by SARS-CoV-2-infected people. Patients in a hospital and an accommodation facility who tested positive for SARS-CoV-2 participated in this study in 2020. Linen samples before washing or disinfection, rinse water after washing or disinfection, air in the workplace at the hospital and an accommodation facility, and the PPE worn by linen-handling people were tested for SARS-CoV-2 RNA and viable viruses. Among 700 samples from 13 SARS-CoV-2-infected participants and their surrounding environment, SARS-CoV-2 RNA was detected from 14% (52/362) of the linens used by COVID-19 patients (cycle threshold [Ct] value: 33-40). SARS-CoV-2 RNA was detected from 8% (2/26) of rinse water after washing or disinfection, from 15% (16/104) of air samples in the workspace, and from 10% (5/52) of gowns worn by linen-handling people, all with high Ct values (> 36). No SARS-CoV-2 was isolated from any samples. The potential risk of SARS-CoV-2 infection from handling linens used by SARS-CoV-2-infected people exists but appears to below.

Impacts of exposure to air pollution, radon and climate drivers on the COVID-19 pandemic in Bucharest, Romania: A time series study

During the ongoing global COVID-19 pandemic disease, like several countries, Romania experienced a multiwaves pattern over more than two years. The spreading pattern of SARS-CoV-2 pathogens in the Bucharest, capital of Romania is a multi-factorial process involving among other factors outdoor environmental variables and viral inactivation. Through descriptive statistics and cross-correlation analysis applied to daily time series of observational and geospatial data, this study aims to evaluate the synergy of COVID-19 incidence and lethality with air pollution and radon under different climate conditions, which may exacerbate the coronavirus' effect on human health. During the entire analyzed period 1 January 2020-21 December 2021, for each of the four COVID-19 waves were recorded different anomalous anticyclonic synoptic meteorological patterns in the mid-troposphere, and favorable stability conditions during fall-early winter seasons for COVID-19 disease fast-spreading, mostly during the second, and the fourth waves. As the temporal pattern of airborne SARS-CoV-2 and its mutagen variants is affected by seasonal variability of the main air pollutants and climate parameters, this paper found: 1) the daily outdoor exposures to air pollutants (particulate matter PM2.5 and PM10, nitrogen dioxide-NO₂, sulfur dioxide-SO₂, carbon monoxide-CO) and radon - ²²²Rn, are directly correlated with the daily COVID-19 incidence and mortality, and may contribute to the spread and the severity of the pandemic; 2) the daily ground ozone-O₃ levels, air temperature, Planetary Boundary Layer height, and surface solar irradiance are anticorrelated with the daily new COVID-19 incidence and deaths, averageingful for spring-summer periods. Outdoor exposure to ambient air pollution associated with radon is a non-negligible driver of COVID-19 transmission in large metropolitan areas, and climate variables are risk factors in spreading the viral infection. The findings of this study provide useful information for public health authorities and decision-makers to develop future pandemic diseases strategies in high polluted metropolitan environments.

The role of outdoor and indoor air quality in the spread of SARS-CoV-2: Overview and recommendations by the research group on COVID-19 and particulate matter (RESCOP commission)

There are important questions surrounding the potential contribution of outdoor and indoor air quality in the transmission of SARS-CoV-2 and perpetuation of COVID-19 epidemic waves. Environmental health may be a critical component of COVID-19 prevention. The public health community and health agencies should consider the evolving evidence in their recommendations and statements, and work to issue occupational guidelines. Evidence coming from the current epidemiological and experimental research is expected to add knowledge about virus diffusion, COVID-19 severity in most polluted areas, inter-personal distance requirements and need for wearing face masks in indoor or outdoor environments. The COVID-19 pandemic has highlighted the need for maintaining particulate matter concentrations at low levels for multiple health-related reasons, which may also include the spread of SARS-CoV-2. Indoor environments represent even a more crucial challenge to cope with, as it is easier for the SARS-COV2 to spread, remain vital and infect other subjects in closed spaces in the presence of already infected asymptomatic or mildly symptomatic people. The potential merits of preventive measures, such as CO₂ monitoring associated with natural or controlled mechanical ventilation and air purification, for schools, indoor public places (restaurants, offices, hotels, museums, theatres/cinemas etc.) and transportations need to be carefully considered. Hospital settings and nursing/retirement homes as well as emergency rooms, infectious diseases divisions and ambulances represent higher risk indoor environments and may require additional monitoring and specific decontamination strategies based on mechanical ventilation or air purification.

SARS-CoV-2 pseudotyped virus persists on the surface of multiple produce but can be inactivated with gaseous ozone

Due to the immense societal and economic impact that the COVID-19 pandemic has caused, limiting the spread of SARS-CoV-2 is one of the most important priorities at this time. The global interconnectedness of the food industry makes it one of the biggest concerns for SARS-CoV-2 outbreaks. Although fomites are currently considered a low-risk route of transmission for SARS-CoV-2, new variants of the virus can potentially alter the transmission dynamics. In this study, we compared the survival rate of pseudotyped SARS-CoV-2 on plastic with some commonly used food samples (i.e., apple, strawberry, grapes, tomato, cucumber, lettuce, parsley, Brazil nut, almond, cashew, and hazelnut). The porosity level and the chemical composition of different food products affect the virus's stability and infectivity. Our results showed that tomato, cucumber, and apple offer a higher survival rate for the pseudotyped viruses. Next, we explored the effectiveness of ozone in deactivating the SARS-CoV-2 pseudotyped virus on the surface of tomato, cucumber, and apple. We found that the virus was effectively inactivated after being exposed to 15 ppm of ozone for 1 h under ambient conditions. SEM imaging revealed that while ozone exposure altered the wax layer on the surface of produce, it did not seem to damage the cells and their biological structures. The results of our study indicate that ozonated air can likely provide a convenient method of effectively disinfecting bulk food shipments that may harbour the SARS-CoV-2 virus.

Presence of SARS-CoV-2 on food surfaces and public space surfaces in three districts of Lima, Peru

The aim of this study was to determine the presence of SARS-CoV-2 on food surfaces and surfaces in public spaces in 3 districts of Lima, Peru. A cross-sectional descriptive study was carried out in three districts of the Lima metropolitan area. Surfaces that were most exposed to users were selected. Samples were swabbed for 4 weeks and transported to the laboratory to determine the presence of the virus. One thousand ninety-five inert surface samples and 960 food surface samples were evaluated for the identification of SARS-CoV-2 by the real time-PCR molecular test, whereby only one sample from an automated teller machine was positive. Most of the inert and food surfaces evaluated did not show the presence of SARS-CoV-2 during the time of sample collection. Despite the negative results, the frequency of disinfection and hygiene measures on high-contact surfaces should be maintained and increased to prevent other highly contagious infectious diseases.

Routine Decontamination of Surfaces Relevant to Working Dogs: Neutralization of Superficial Coronavirus Contamination

Given the increased deployment of working dogs to settings with pathogenic biological agents, a safe, effective, and logistically feasible surface decontamination protocol is essential to protect both the animals and their human handlers. Our group previously found that superficial contamination on surfaces relevant to the working dog community, including leashes and toys, could be significantly reduced using a standardized wiping protocol with various cleansing products. To expand upon this work, we analyzed the ability of this protocol to decontaminate surface-deposited bovine coronavirus, which was used as a BSL2 surrogate for SARS-CoV-2. Unsurprisingly, the physical characteristics of a given surface, including porosity and texture, had a significant effect on the ability to recover viable virus remaining on the surface post treatment. After correcting for these differences, however, wiping with 70% isopropyl alcohol (IPA) and 0.5% chlorhexidine performed best, reducing viral titers by >3 log on plastic bumper toys and nylon collars, and by >2 log on rubber toys and tennis balls. Leather leashes and Velcro proved more difficult to decontaminate, but both still showed significant loss of viral contamination following wiping with IPA or chlorhexidine. This work (i) validates the utility of a simple protocol for the neutralization of viruses on several surfaces, (ii) identifies materials that are more difficult to decontaminate, which should, thus, be considered for removal from field use, and (iii) highlights the need for further development of protocols testing porous or textured surfaces.

Knowledge about COVID-19 Best Practices in the North of Portugal and the Importance of Health Education in the Prevention of Pandemic Events

The rapid global spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has made COVID-19 one of the biggest pandemics of all time, with several devastating public health challenges. In this study, we investigated the knowledge towards COVID-19 best practices in the north of Portugal. Methods: A descriptive cross-sectional study was performed with a convenience sample of the population of northern Portugal to assess their knowledge about COVID-19, SARS-CoV-2 and measures to prevent and mitigate pandemics. An online validated questionnaire was completed by 411 participants, from September to October 2020. Results: The overall correct knowledge was 81.3%, which indicates a good knowledge by the northern Portuguese respondents about COVID-19. The correct answer score differed considerably between men and women, being significantly higher among the latter (12.28 ± 1.22; p = 0.011). Moreover, the highest knowledge was observed in participants who attended high school or above (12.27 ± 1.21; p < 0.000). Conclusion: This study contributes to the analysis of COVID-19 knowledge by the northern Portuguese population, emphasizes the crucial role of health education in the control and mitigation of the COVID-19 pandemic, and provides field-based evidence to prevent the next pandemic event.

Sponge Whirl-Pak Sampling Method and Droplet Digital RT-PCR Assay for Monitoring of SARS-CoV-2 on Surfaces in Public and Working Environments

The SARS-CoV-2 can spread directly via saliva, respiratory aerosols and droplets, and indirectly by contact through contaminated objects and/or surfaces and by air. In the context of COVID-19 fomites can be an important vehicle of virus transmission and contribute to infection risk in public environments. The aim of the study was to analyze through surface sampling (sponge method) the presence of SARS-CoV-2 in public and working environments, in order to evaluate the risk for virus transmission. Seventy-seven environmental samples were taken using sterile sponges in 17 animal farms, 4 public transport buses, 1 supermarket and 1 hotel receptive structure. Furthermore, 246 and 93 swab samples were taken in the farms from animals and from workers, respectively. SARS-CoV-2 detection was conducted by real-time RT-PCR and by digital droplet RT-PCR (dd RT-PCR) using RdRp, gene E and gene N as targets. None of the human and animal swab samples were positive for SARS-CoV-2, while detection was achieved in 20 of the 77 sponge samples (26%) using dd RT-PCR. Traces of the RdRp gene, gene E and gene N were found in 17/77 samples (22%, average concentration 31.2 g.c./cm², range 5.6 to 132 g.c./cm²), 8/77 samples (10%, average concentration 15.1 g.c./cm², range 6 to 36 g.c./cm²), and in 1/77 (1%, concentration 7.2 g.c./cm²). Higher detection rates were associated with sampling in animal farms and on public transport buses (32% and 30%) compared to the supermarket (21%) and the hotel (no detection). The result of the study suggests that the risk of contamination of surfaces with SARS-CoV-2 increases in environments in which sanitation strategies are not suitable and/or in highly frequented locations, such as public transportation. Considering the analytical methods, the dd RT-PCR was the only approach achieving detection of SARS-CoV-2 traces in environmental samples. Thus, dd RT-PCR emerges as a reliable tool for sensitive SARS-CoV-2 detection.

The role of toothbrush in the transmission of corona- and influenza viruses - results of an in vitro study

Objectives

The aim of this in vitro study was to investigate viruses’ stabilities on manual toothbrushes using feline coronavirus (FeCoV) as representative of coronaviruses and an Avian influenza A virus H1N1 for influenza viruses.

Material and methods

Two viruses, FeCoV (Strain Munich; titer 107.5 TCID50/ml) and H1N1 (RE 230/90; titer 106.5 TCID50/ml), were used in this study. Manual toothbrushes were disassembled into bristles, bristle fixation, and back of the toothbrush head, contaminated with the viruses and air-dried for 24 h. In a second experiment, whole toothbrush heads were contaminated, rinsed with water (5 ml for 15 s) and then air-dried.

Results

For FeCoV, immediately after contamination, the following average titers were recovered: fixation: 10^6.41, back of head: 10^6.81 and bristles: 10^6.63 TCID₅₀/ml. Following air-drying of 12 (fixation) and 24 h, titers of ≤ 10^2.5, 10^3.75, and 10^2.72 TCID₅₀/ml were found in the respective groups, with a detection limit of 10^2.5 TCID₅₀/ml. For H1N1, immediately after contamination, the following average titers could be recovered: fixation: 10^5.53, back of head: 10^5.97 and bristles: 10^5.75 TCID₅₀/ml. Following air-drying of 8 (fixation) and 24 h, titers were ≤ 10^2.5, 10^3.63, and 10^3.53 TCID₅₀/ml in the respective group, again with 10^2.5 TCID₅₀/ml being the detection limit. In case of water rinse, no infectious virus could be recovered after 12 h.

Conclusion

Viral load of both viruses is reduced by air-drying, especially following water rinsing.

Clinical relevance

The toothbrush itself plays an insignificant role in the self-transmission of coronavirus and influenza virus.

Immunouniverse of SARS-CoV-2

SARS-CoV-2 virus has become a global health problem that has caused millions of deaths worldwide. The infection can present with multiple clinical features ranging from asymptomatic or mildly symptomatic patients to patients with severe or critical illness that can even lead to death. Although the immune system plays an important role in pathogen control, SARS-CoV-2 can drive dysregulation of this response and trigger severe immunopathology. Exploring the mechanisms of the immune response involved in host defense against SARS-CoV-2 allows us to understand its immunopathogenesis and possibly detect features that can be used as potential therapies to eliminate the virus. The main objective of this review on SARS-CoV-2 is to highlight the interaction between the virus and the immune response. We explore the function and action of the immune system, the expression of molecules at the site of infection that cause hyperinflammation and hypercoagulation disorders, the factors leading to the development of pneumonia and subsequent severe acute respiratory distress syndrome which is the leading cause of death in patients with COVID-19.

Survival of SARS-CoV-2 in artificial seawater and on the surface of inanimate materials

There is a potential risk for severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) spread through human contact with seafood and the inanimate materials contaminated by the virus. In this study, we examined the stability of the virus in artificial seawater (ASW) and on the surface of selected materials. SARS‐CoV‐2 (3.75 log₁₀ TCID₅₀) in ASW at 22℃ maintained infectious about 3 days and at 4℃ the virus survived more than 7 days. It should be noticed that viable virus at high titer (5.50 log₁₀ TCID₅₀) may survive more than 20 days in ASW at 4℃ and for 7 days at 22℃. SARS‐CoV‐2 on stainless steel and plastic bag maintained infectious for 3 days, and on nonwoven fabric for 1 day at 22℃. In addition, the virus remained infectious for 9 days on stainless steel and non‐woven fabric, and on plastic bag for 12 days at 4℃. It is important to highlight the role of inanimate material surfaces as a source of infection and the necessity for surface decontamination and disinfection.

Nanoparticle and bioparticle deposition kinetics

Mechanisms and kinetic of particle deposition at solid surfaces leading to the formation of self-assembled layers of controlled structure and density were reviewed. In the first part theoretical aspects were briefly discussed, comprising limiting analytical solutions for the linear transport under flow and diffusion. Methods of the deposition kinetics analysis for non-linear regimes affected by surface blocking were also considered. Characteristic monolayer formation times under diffusion and flow for the nanoparticle size range were calculated. In the second part illustrative experimental results obtained for micro- and nanoparticles were discussed. Deposition at planar substrates was analyzed with emphasis focused on the stability of layers and the release kinetics of silver particles. Applicability of the quartz microbalance measurements (QCM) for quantitative studies of nanoparticle deposition kinetic was also discussed. Except for noble metal and polymer particles, representative results for virus deposition at abiotic surfaces were analyzed. Final part of the review was devoted to nanoparticle corona formation at polymer carrier particles investigated by combination of the concentration depletion, AFM, SEM and the in situ electrokinetic method. It is argued that the results obtained for colloid particles can be used as reliable reference systems for interpretation of protein and other bioparticle deposition, confirming the thesis that simple is universal.

SARS-CoV-2 cold-chain transmission: Characteristics, risks and strategies

Low temperature and certain humidity are conducive to severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) for long‐time survival and long‐distance spread during logistics and trades. Contaminated cold‐chain or frozen products and outer packaging act as the carrier of SARS‐CoV‐2, that infects the high‐risk population who works in the ports, cold storage or seafood market. Since the coronavirus disease 2019 (COVID‐19) pandemic worldwide, multiple localized outbreaks caused by SARS‐CoV‐2 contaminated imported cold‐chain products have been reported in China, which brought challenges to COVID‐19 prevention and control. Here, we review the evidences of SARS‐CoV‐2 cold‐chain transmission from six confirmed cold‐chain related COVID‐19 outbreaks in China, especially in terms of SARS‐CoV‐2 whole‐genome sequencing and virus isolation. In addition, we summarize the characteristics and mode of SARS‐CoV‐2 cold‐chain transmission from both six COVID‐19 outbreaks in China and the outbreaks suspected cold‐chain transmission in other countries. Finally, we analyze the underlying risks of SARS‐CoV‐2 cold‐chain transmission and propose the preventive countermeasures.

SARS‐CoV‐2 contaminated cold‐chain products can infect high‐risk populations and subsequently cause community transmission

Specific locations, such as seafood market stalls, can amplify outbreaks

Cold‐chain fomites accelerate global spread of SARS‐CoV‐2 and cause “silent transmission”

Rational sampling, comprehensive disinfection, protection of high‐risk groups and pollution classification are the main strategies