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Contamination of inert surfaces by SARS-CoV-2: Persistence, stability and infectivity. A review
Abstract
Undoubtedly, there is a tremendous concern regarding the new viral strain "Severe Acute Respiratory Syndrome Coronavirus-2" (SARS-CoV-2) and its related disease known as COVID-19. The World Health Organization has stated that SARS-CoV-2 is mainly transmitted from person-to-person close contact, as well as by small aerosol respiratory droplets. Moreover, the results of some recent studies about the role of air pollution on the spread and lethality of the novel coronavirus suggest that air contaminants could be also a transmission pathway of the virus. On the other hand, indirect transmission of the virus cannot be discarded. Among many sources of indirect transmission, there is the contamination of inert/inanimate surfaces. This manuscript was aimed at reviewing the scientific literature currently available in PubMed and Scopus. The results of the reviewed studies point out that SARS-CoV-2 can last on different surfaces from hours to a few days. However, rapid SARS-CoV-2 inactivation is possible by applying commonly available chemicals and biocides on inanimate surfaces. Consequently, although the presence of SARS-CoV-2 on inanimate surfaces can represent a potential route of transmission, appropriate disinfection measures should reduce the possibilities of coronavirus transmission, and hence, significantly decrease the risks of COVID-19.
... Yet, history has shown that decontamination protocols may aid in reducing viral transmission, as demonstrated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) [1]. As the aftermath of the COVID-19 pandemic continues to unfold, data indicate that SARS-CoV-2 can survive on surfaces for days [2][3][4]. This underlines the urgent need for efficient high touch surface disinfection or equipment sterilization methods in health care settings and public indoor spaces. ...
... The rational regression model was used to interpolate and predict radiant exposure (mJ cm −2 ) required for incremental log inactivation of the experimental microbial panel. Predicted values were extracted for each log reduction (1)(2)(3)(4) where applicable (Supplementary Table 2). ...
... This factor was not parsed in this work, yet it was controlled with microbe-containing droplets exposed to air for the same duration without radiation. Inocula, suspension, and survival time in experimental buffers, in biological materials and on surfaces, whether for bacteria or viruses should equally be considered, as previous research has demonstrated that these factors can impact viability over long periods of time [3,59,[62][63][64][65]. Difficulties in delivering uniform UV dosage and optical phenomena such as radiation profiles and reflection at surface may further hinder [66]. ...
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.
Graphical abstract
... Clusters in meat processing plants with 25 cases or more were described if they were reported in mainland France between 1 May 2020 and 30 June 2021. Only establishments with cutting lines were described, regardless of the presence of slaughtering and tertiary processing activities. ...
... Humidity and temperature in production facilities have a major impact on the persistence of viruses such as SARS-CoV-2 (23)(24)(25). In meat processing plants, these parameters are also important for the growth of microorganisms found on meat, and thus, for food safety (26). ...
Introduction
Several COVID-19 outbreaks have been reported in meat processing plants in different countries. The aim of this study was to assess the environmental and socio-economic risk factors favouring the transmission of SARS-CoV-2 in meat processing plants and to describe the prevention measures implemented.
Methods
Data from epidemiological investigations of COVID-19 clusters in France, the scientific literature, structured interviews and site visits were collected and summarised to investigate the main risk factors for SARS-CoV-2 infection in meat processing plants, including determinants within and outside the workplace.
Results
An increased risk of infection was identified among workers with unfavourable socio-economic status (temporary/non-permanent workers, migrants, ethnic minorities, etc.), possibly related to community activities (house-sharing, car-sharing, social activities). Working conditions (proximity between workers) and environmental factors (low temperatures and inadequate ventilation) also appear to be important risk factors. These environmental conditions are particularly prevalent in cutting and boning plants, where the majority of reported cases are concentrated. Preventive measures applied included screening for COVID-19 symptoms, testing, wearing masks, increased hygiene and sanitation, physical and temporal distancing, control of ventilation. Certain food safety hygiene measures were compatible with protecting workers from SARS-CoV-2. The hygiene culture of agri-food workers made it easier to implement preventive measures after adaptation.
Conclusion
This study made it possible to identify the environmental and socio-economic factors conducive to the transmission of SARS-CoV-2 in meat processing plants. The knowledge gained from this work was used in simulations to understand the transmission of the virus in the plants.
... This ongoing pandemic marks the third instance of a newly identified zoonotic coronavirus within the span of two decades, resulting from the SARS-CoV-2 virus, which causes severe acute respiratory syndrome. Quickly after the COVID-19 pandemic outbreak, an explosion of publications has emerged, which are dedicated to different aspects varying from the transmission mechanisms of the SARS-CoV-2 virus to its attachment to the environment, transmission mechanisms [2][3][4][5], its binding to receptors and abiotic surfaces (fomites) [6][7][8][9], and its inactivation and elimination [9,10] to vaccination [11]. ...
... Similarly, bound antibodies dissociate at a rate that depends on the concentration of bound ligands and the dissociation rate constant k off . Only an initial condition is required for the binding reaction (8). This condition is [AB](t=0)=0 i.e. at the initial time t=0, no SARS-CoV-2 /Anti-SARS-CoV-2 complex is formed. ...
... Ainda vale destacar que, o vírus SAR-COV-2 pode ser identificado em superfície por um tempo que varia de horas a dias de acordo com o material do objeto (Marquès, 2021;Domingo, 2021), no qual pode causar contaminação de mãos, ou outras partes do corpo que podem ser direcionadas para olhos, boca ou nariz. Objetos como maçanetas, trincos, ferrolhos, botões de elevadores, interruptores e torneiras são de uso coletivo e essencial. ...
... Ainda vale destacar que, o vírus SAR-COV-2 pode ser identificado em superfície por um tempo que varia de horas a dias de acordo com o material do objeto (Marquès, 2021;Domingo, 2021), no qual pode causar contaminação de mãos, ou outras partes do corpo que podem ser direcionadas para olhos, boca ou nariz. Objetos como maçanetas, trincos, ferrolhos, botões de elevadores, interruptores e torneiras são de uso coletivo e essencial. ...
Avaiable in: https://www.proceedings.blucher.com.br/article-details/joi-personal-equipment-to-manipulate-knobs-without-direct-hands-contact-38555
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The contagious COVID-19 pandemic made it necessary to adopt strategies to avoid contamination. COVID-19 spreads when someone is in direct contact with small droplets and particles that contain the virus. These droplets and particles can be active on surfaces that are shared by many people, so hand sanitation became an important aspect to prevent virus contamination. However, products for hand sanitation may not be available easily everywhere. Moreover, the excessive use of products like hand sanitizers and hand soaps can cause dryness and dermatitis on certain users. This paper describes the rapid prototyping of JOI, a device for users to avoid touching doorknobs, door bolts, switchers, and call buttons. The device was 3D printed (more than 400 units) and distributed to an academic community, which then answered a usability survey. Results show that the device is efficient to avoid the direct contact of users and surfaces that may be contaminated.
... 2 The SARS-COV2 viruses and their variants are transmitted via aerosols, stay on different surfaces (including that of electronic devices) for varied lengths of time (hours and days) and at different locations such as hospitals and may be transferred to people who after surface contact then touch their face, mouth, nose and eyes. 8,9 It thus has the potential to be one of those microbes being transmitted across surfaces including those of electronic devices. 8 Therefore, a person may carry the pathogen on their mobile device and accidentally infect self and others. ...
... 8,9 It thus has the potential to be one of those microbes being transmitted across surfaces including those of electronic devices. 8 Therefore, a person may carry the pathogen on their mobile device and accidentally infect self and others. ...
Following COVID-19 protocols implemented globally, it is prudent to extend this to mobile phones, regarded as carriers of microbes, as these are used extensively in clinical settings for learning and patient care. AIM: Was to determine types of microbes harbored on mobile phones and related hygiene practices whilst using these in aerosol and non-aerosol generating dental settings METHODOLOGY: This cross-sectional study was conducted in two parts: A laboratory study to determine the prevalence of microbes on mobile phones and a questionnaire survey to determine the related knowledge and behavior of phone users in both aerosol and non-aerosol generating dental clinics. All proper protocols (consent, ethics) were adhered to RESULTS: A small percentage (27.2%) of swabs of mobile phones yielded a positive bacterial culture, of these 72% were from the AGP dental setting. Gram positive and negative microorganisms were distinguishable, indicating a diverse group of microbes. Students and staff indicated good mobile phone hygiene practices, but there is place for improvement. Their related knowledge of disinfectants and use were acceptable, but not having mobile phone coverings was problematic CONCLUSION: Faculty protocols for disinfecting mobile phones and standardized guidelines for its use in aerosol or non-aerosol clinics is recommended
... Similarly, SARS-CoV-2, though primarily known to be transmitted via the respiratory route, has the potential to be transmitted via contaminated surfaces (Baker & Gibson, 2022a;Choi et al., 2021;Van Doremalen et al., 2020). For example, a review by Marquès and Domingo (2021) indicated that SARS-CoV-2 can persist on various surfaces (e.g., plastic and stainless steel) ranging from hours to a few days. Given the ability to persist on surfaces, subsequent transmission via contaminated hands and control via available hand hygiene approaches is important to characterize. ...
Surfaces contaminated with enveloped viruses, such as severe acute respiratory syndrome coronavirus 2 and influenza virus, can potentially spread illness via hand contact. Often, the efficacy of hand hygiene interventions relies on virus recovery from hands. However, the recovery of bacteriophage phi6 (Φ6), a recommended surrogate for enveloped viruses, from the entire hands using the ASTM E2011-21 standard has not been optimized. For Φ6 recovery from the hands, three eluents [lysogeny broth (LC), tryptic soy broth (TSB), and 1.5% beef extract (BE)] and three recovery methods [glove juice method (GJM), hand rinsing, and modified dish method] were examined. The effects of inoculum application on either the palmar surface or the whole hand were compared, and virus recovery was assessed under wet and dry conditions to identify the optimal combinations for maximizing Φ6 recovery. Statistical differences among methods, inoculum application, and recovery types were identified. While no statistical difference was observed among the eluents (P = 0.281), LC demonstrated the highest Φ6 recovery efficiency, while TSB and BE had comparable recoveries. Two-way interaction effects were observed between method type vs. application type (P ≤ 0.05), method type vs. recovery type (P ≤ 0.05), and application type vs. recovery type (P ≤ 0.05), indicating these factors influencing one another. Additionally, no Φ6 recovery was obtained for the dry basis recovery type and the GJM method type. Based on the present study, to maximize Φ6 recovery from the hands during hand hygiene studies, inoculum should be applied to the palmar surface and recovered while it is still wet using LC.
... Notably, evidence from numerous studies has indicated the extended viability of SARS-CoV-2 on surfaces such as glass, plastic, paper, and stainless steel. It emphasizes the importance of intensifying disinfection protocols for these materials and considering material characteristics when selecting protective equipment so as to limit the spread of viruses in future pandemics (Gidari et al., 2021;Xu et al., 2023;Marquès and Domingo, 2021). ...
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.
... Broadly speaking, SARS-CoV-2, similar to other human coronaviruses, can remain infectious on dry surfaces at room temperature for a considerable amount of time -ranging from hours to days. Nevertheless, it has been proven that the virus can be efficiently inactivated through surface disinfection (20). To mitigate the possible transmission of SARS-CoV-2 from surfaces, the WHO suggests the utilization of water, detergents, and disinfectants as effective means to decontaminate surfaces and create a more sanitized environment (16,21,22). ...
Background: SARS-CoV-2, the causative agent of the COVID-19 pandemic, spreads through both direct and indirect pathways. Among the latter, surface contamination is a significant concern due to the virus’s prolonged viability on surfaces. There is ongoing discussion over the impact of environmental surface contamination, especially in light of the introduction of novel viral types. The present study aimed to examine the extent of environmental surface contamination across different hospital wards and evaluate the effectiveness of disinfectants in inactivating the virus. Methods: The samples were collected from critical areas in a hospital, both pre-disinfection (n=40) and post-disinfection (n=17), using reverse transcription-polymerase chain reaction (RT-PCR) to detect SARS-CoV-2. Results: The findings indisputably confirm the presence of SARS-CoV-2 on swab samples from frequently-touched surfaces. Notably, 10 samples were virus-positive before disinfection, highlighting persistent viral contamination in vital hospital zones. Conclusion: This study underscores the critical role of environmental surface contamination in SARSCoV-2 transmission, particularly in healthcare settings. Detecting the virus on frequently-handled surfaces underscores the urgent need for rigorous and frequent surface disinfection. Effective surface disinfection remains a rapid, straightforward, and practical strategy to mitigate virus transmission to healthcare workers and patients. These findings hold significant implications for infection control, particularly amid emerging virus variants. They emphasize the need to maintain stringent hygiene and disinfection practices within healthcare facilities to combat the spread of COVID-19.
... An earlier investigation showed that while lopinavir/ritonavir therapy was associated with better outcomes, it did not improve the patient's clinical recovery from COVID-19 infection. [143] Although lopinavir's efficacy for treating COVID- 19 has not yet evaluated, but USA, Japan, and Singapore treat COVID-19 patients with such ritonavir/lopinavir combination. The lopinavir/ritonavir efficacy for COVID-19 is now being studied in clinical trials in many countires such as France, Spain, Thailand, China, Hong Kong, Canada, and the United States. ...
Amidst the ongoing global challenge of the SARS-CoV-2 pandemic, the quest for effective antiviral medications remains paramount. This comprehensive review delves into the dynamic landscape of FDA-approved medications repurposed for COVID-19, categorized as antiviral and non-antiviral agents. Our focus extends beyond conventional narratives, encompassing vaccination targets, repurposing efficacy, clinical studies, innovative treatment modalities, and future outlooks. Unveiling the genomic intricacies of SARS-CoV-2 variants, including the WHO-designated Omicron variant, we explore diverse antiviral categories such as Fusion inhibitors, Protease inhibitors, Transcription inhibitors, Neuraminidase inhibitors, Nucleoside reverse transcriptase, and non-antiviral interventions like Importin α/β1-mediated nuclear import inhibitors, Neutralizing antibodies and convalescent plasma. Notably, Molnupiravir emerges as a pivotal player, now licensed in the UK. This review offers a fresh perspective on the historical evolution of COVID-19 therapeutics, from repurposing endeavors to the latest developments in oral anti-SARS-CoV-2 treatments, ushering in a new era of hope in the battle against the pandemic.
... The biomedical engineering disciplines of tissue engineering, drug delivery, biosensing, bioimaging, and cancer therapy and diagnostics have benefited greatly from these carbon nanomaterials. For the past 10 years, graphene oxide (GO), also known as oxidized graphite, has been the focus of much study [160]. The fact that graphene oxide dissolves readily in water as compared to graphene has encouraged study into potential biological applications. ...
Graphene-based materials have garnered significant interest in the burgeoning field of contemporary flexible and bendable technologies. Graphene has emerged as a prime candidate for the development of flexible electronics due to its outstanding electrical, mechanical, and optical properties, coupled with the ease of functionalizing its derivatives. This review provides an exhaustive analysis of the latest advancements in the synthesis and applications of graphene-based composites. Exceptional properties of Graphene including high thermal conductivity, chemical stability, optical transparency, high current density, and increased surface area, have broad implications across thermodynamics, chemistry, optics, and mechanics. The growing use of graphene oxide materials across various industries has fueled a surge in interest. The synthesis of graphene oxide compounds follows established procedures such as those by Brodie, Staudenmaier, and Tour, with ongoing discussions on large-scale production using various oxidants. Recent developments have led to numerous new, enhanced, and modified Hummers techniques for producing graphene oxide. Graphene oxide (GO) serves as a crucial foundational material for a wide range of applications, including energy storage, water purification, and as a composite in biosensors, electronics, and hazardous gas removal. This review delves into these applications, highlighting GO's role in improving the efficiency and performance of these technologies. Additionally, the paper addresses the current challenges and obstacles in the development and application of graphene, providing insights into potential solutions and future research directions. By offering a comprehensive and practical database, this review aims to facilitate the future development of graphene-based composite materials, driving innovation and advancements in various high-impact applications.
... It has been reported that effective disinfectants are critical in curbing viral transmission to susceptible populations [13]. While previous research has extensively characterized the biocidal properties of disinfectants, understanding their molecular interactions with viral components remains a key area of investigation [13,14]. The ligand-binding energy (LBE) between a disinfectant and viral protein is a critical determinant of antiviral efficacy, indicating the potential for stable and strong complex formation [15]. ...
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.
... It has been reported that effective disinfectants are critical in curbing viral transmission to susceptible populations [13]. While previous research has extensively characterized the biocidal properties of disinfectants, understanding their molecular interactions with viral components remains a key area of investigation [13,14]. The ligand binding energy (LBE) between a disinfectant and viral protein is a critical determinant of antiviral efficacy, indicating the potential for stable and strong complex formation [15]. ...
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, ligand binding energies (LBEs) of selected disinfectants were predicted and combined with their environmental impacts and costs through eco-pharmaco-economic analysis (EPEA). Results revealed the binding affinities of chemical disinfectants to viral proteins varied significantly (p
... When an infected person comes in contact with another person, the virus spreads via tiny droplets of the infected person's mouth/nose.SARS-CoV2 can also be transmitted via infected surfaces. Various researches have reported that viruses stayed infected surfaces from few hours to days[2, 3,4]. Little pieces of evidence have been found for surfaces infection, still, deep cleaning procedures are followed, some researchers have raised questions on said procedures [5]. ...
It has been almost two years since the coronavirus outbreak. It was declared a pandemic in March 2020 and has impacted everyone's life one way or another. SARS-CoV2 means Severe acute respiratory syndrome coronavirus 2, and it is the virus that causes COVID-19. It presents major health, social and economic crisis all over the world. Many theories had been presented, several types of research were done all over the world. This paper presents a simple overview of the COVID-19, detailed pathogenesis, and its perceptive in India. India has one of the largest populations in the world. Introducing reforms and their execution requires effort. Paper summarizes the efforts done in India to control the pandemic.
... Comparatively, laboratory simulation studies need to explore the survival and decay of infectious viruses under controlled conditions, which is very important for epidemiological analysis and risk modelling [12 , 13] . Laboratory studies on the infectivity of coronaviruses and influenza A viruses (IAVs) on different surfaces and/or aerosols have been reviewed [14][15][16][17][18] . These viruses were reported to survive from hours to days on different surfaces. ...
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.
... In addition, SARS-CoV-2 can persist on environmental surfaces for extended periods, sometimes up to months. Taken together, recent aggregated studies suggest that SARS-CoV-2 RNA can be readily detected on surfaces and fomites [10], and strengthen the possibility of contaminated environmental samples for SARS-CoV-2 transmission [11]. Notably, the virus SARS-CoV-2, the causative agent of COVID-19, can be acquired by exposure to fomites, although the infectious risk through fomites is probably multifactorial and is affected by several environmental stressors, including humidity, temperature, and ventilation [12]. ...
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.
... Specifically, the formulation involving virucidal copper-PCL/PVP nanofibers at 0.75% demonstrates excellent efficacy, achieving 99.999% inhibition of viral activity within 24 h against the coronavirus, while remaining noncytotoxic to L929 cells. Furthermore, and according to previous studies already published, the coronaviruses, including SARS-CoV-2 and SARS-CoV-1, can survive on nonporous stainless steel, plastic, and glass surfaces for up to 72 h45,46 and 1 h on copper surfaces.47 Therefore, the ability of the 0.75% copper-PCL/PVP virucidal nanofibers to promptly release Cu 2+ ions in a hydrophilic medium can be an advantage for specific applications, such as preventing COVID-19 infection in a high humidity environment, playing its role as a filtration medium. ...
This work investigated the virucidal property of copper-loaded poly(ε-caprolactone) (PCL)/polyvinylpyrrolidone (PVP) blended nanofibers against coronavirus. Electrospinning solutions were prepared with 0.25, 0.75, and 1.50% [w/v] of copper salt and their properties of electrical conductivity, surface tension, and viscosity were measured. The copper-PCL/PVP nanofibers produced electrospun composite membranes of 30.5–38 g m−2. IR spectra confirmed the blended PCL/PVP, and SEM/EDS images revealed the morphology of the randomly oriented nanofibers with homogeneously incorporated copper in the electrospun nanofibers. The copper quantification indicated the final incorporation of 5.50 ± 0.31, 14.00 ± 1.03, and 27.10 ± 3.00 mg g−1 of copper, as measured by atomic absorption spectrometry, into electrospun composite membranes for 0.25, 0.75, and 1.50% [w/v] copper solution formulations, respectively, and these compositions also affected the nanofibers mechanical properties. Copper release assays showed that copper-PCL/PVP nanofibers readily release ions into aqueous media. The 0.75% copper-PCL/PVP composite membrane was virucidal against coronavirus, reaching 99.99% inactivation in 1 hour and 99.999% inactivation in 24 h, and non-cytotoxic to L929 cells in 24 h of exposure. This work presents a virucidal composite membrane with potential use in personal protective equipment against viral outbreaks or pandemics.
... To assess the impact of air pollutants on COVID-19 disease transmission and lethality during the 26 February 2020-31 March 2022 period, with five recorded waves of COVID-19 in Bucharest, this study analyzed time series of the daily average PM2.5 and PM10. In good accordance with the numerous studies which have explicitly examined the harmful effects of particulate matter on COVID-19 transmission [67][68][69], the results of this research show direct positive correlations of PM2.5 concentrations, PM10 concentrations, and the derived PM2.5/PM10 ratio with daily new COVID-19 cases (DNCs) and deaths (DNDs) ( Table 1). The outdoor PM2.5 and PM10 temporal patterns, for the entire analyzed period, show seasonal variation with lower values during the spring-summer periods and higher values for the fall-winter seasons (Figure 3). ...
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.
... The COVID-19 pandemic demonstrated that there is a need for new materials to deal with sanitary emergency. Microbes on fomites cause infections in patients within healthcare units [1]. Decreasing the risk of contagion by contact with contaminated surfaces is a critical issue, not only for the SARS-CoV-2 virus but also for other disease-carrying bacteria and viruses in daily life. ...
... 3,4 Another mode of transmission has been reported to be indirect, as a result of interaction with contaminated surfaces and subsequent touching behaviors of organs such as the eyes, mouth and face. 5 Zhang et al. emphasized that the ocular transmission may also be a potential route for COVID-19 infection. 6 Although it was thought that fomites might be partially responsible for the transmission of the SARS-CoV-2 in the initial phase of the pandemic, current evidence indicates that the primary route is the airborne transmission. ...
... Many coronaviruses exist and are associated with diverse tropisms (respiratory for the majority of human coronaviruses [1][2][3], enteric for a large number of livestock CoVs [4,5], and neurological in some cases [e.g., porcine hemagglutinating encephalomyelitis virus] [6]). Interestingly, SARS-CoV-2, in addition to its respiratory tropism, has been repeatedly detected in stool samples of infected patients (7) (for review, see reference 8) for long periods (9), even in the absence of any gastrointestinal symptoms (10,11), calling into question, in the early time of the pandemic, the potential risk of fecal-oral or fecal-respiratory transmission (12)(13)(14)(15)(16)(17)(18). ...
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.
... COVID-19 virus is mainly spread in close contact with an infected person. The virus can also spread via contaminated surfaces (Marquès & Domingo, 2021). Persons remain infectious in moderate cases for up to 10 days and in serious cases for two weeks. ...
... Virus survival or the successful detection of viral RNA depends on the virus variant, the medium in which it is present and environmental conditions (temperature, pH, moisture content, organic matter, light, etc.) [35]. Although the SARS-CoV-2 virus is stable on most indoor surfaces [36][37][38], other factors in outdoor environments may reduce its survival [39]. Studies on the effect of temperature on SARS-CoV-2 survival showed that it might survive from 5 to 10 days at 20 • C and from 1 to 4 days at 30 • C, depending on the surface type [40]. ...
Simple Summary
COVID-19 emerged in China in 2019. It is caused by an until-then unknown coronavirus that causes severe acute respiratory syndrome (SARS-CoV-2). Through experimental infections in the search for a suitable animal model and reported infections in pets early in the pandemic, it became clear that several animal species may be susceptible to SARS-CoV-2 infection. According to the open access dataset of reported SARS-CoV-2 events in animals, about 119 zoo animals have been reported with a SARS-CoV-2 infection. However, the detection of SARS-CoV-2 infections in zoo animals has relied on the observation of symptoms (cough, nasal discharge), behaviour changes (reduced appetite, lethargy), or death of these captive animals. SARS-CoV-2 infections may therefore remain undetected if animals do not show obvious symptoms. In this study, we investigated the potential circulation of SARS-CoV-2 in zoo mammal species by sampling and screening faecal samples from all the mammals in two zoos in Belgium between September 2020 and July 2021 using molecular biology techniques. This study is the first to our knowledge to conduct active SARS-CoV-2 surveillance for several months in all mammal species in a zoo. We conclude that at the time of our investigation, none of the screened animals were excreting SARS-CoV-2.
Abstract
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 present work exploited this observation to develop a format for non-invasive, resource-sparing sample archiving, extends the sampling period, and uses ordinary printer paper. In addition, the distinction between detectable RNA and infective virus is important to keep in mind, since virions can be rendered non-infectious before RNA becomes non-detectable (18). ...
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.
... A patient suffering from COVID-19 may transmit the disease not only to the dentist and dental assistant through aerosols, but also to other patients through aerosols remaining in the environment and on surfaces for a long time. A previous study showed that SARS-COV-2 can survive in different environmental situations from hours to days [10]. Dental procedures involve the use of rotating instruments such as handpieces, ultrasonic scalers, and air-water syringes. ...
Background and Aim: Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) that caused the coronavirus disease-2019 (COVID-19) pandemic is transmitted through close contact via respiratory droplets when an infected patient sneezes, coughs, or talks. Due to close contact with patients, dentists are at higher risk of COVID-19. The aim of this study was to evaluate the knowledge and practice of general dentists in Zanjan regarding the COVID-19.
Materials and Methods: This cross-sectional study was conducted on 107 general dentists working in Zanjan city in September 2021, simultaneous with the fifth wave of the COVID-19, who were selected by census sampling. A researcher-designed questionnaire was used to assess the knowledge and practice after assessing its reliability and validity. The effect of age, gender, work experience, and place of work on knowledge and practice of dentists was analyzed by one-way ANOVA, independent sample t-test, and Pearson’s correlation test (alpha=0.05).
Results: Of all, 89 questionnaires were returned. The mean age of the participants was 35.9 years, and 77.5% of dentists acquired their knowledge about COVID-19 pandemic through the social networks. The mean knowledge and practice scores of dentists were 70.73±10.67 and 58.51±12.81, respectively (out of 100). Dentists with 5 to 15 years of work experience had the highest level of knowledge (P=0.018). The practice score significantly increased with age (P=0.003). Also, dentists with more than 15 years of work experience acquired higher practice scores (P=0.000)
Conclusion: Dentists' knowledge and practice regarding COVID-19 and its treatment was moderate to high (optimal). However, their knowledge and practice were still far from the ideal level, indicating the need for educational planning to enhance their knowledge and improve their practice to deal with COVID-19.
... Environmental transmission can occur when an infected person touches their mouth or nose and then touches a surface, leaving behind virus-carrying droplets. Another person can then touch the contaminated surface and inadvertently transfer the virus to their mouth, nose, or eyes (Krishan and Kanchan 2020;Sharun et al. 2021;Marquès and Domingo 2021 Environmental transmission can also occur through the inhalation of virus-carrying droplets or aerosols in the environment rather than that in close contact situations, such as when people are talking, coughing, or sneezing near each other, leading to direct transmission. This can happen in poorly ventilated spaces where the virus can accumulate and remain suspended in the air for longer periods (Coccia. ...
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.
... COVID-19 virus is mainly spread in close contact with an infected person. The virus can also spread via contaminated surfaces (Marquès & Domingo, 2021). Persons remain infectious in moderate cases for up to 10 days and in serious cases for two weeks. ...
Viral respiratory infection such as severe acute coronavirus-2 disease (SARS-CoV-2) and bacterial co-infections commonly are identified and a major cause of morbidity, mortality requiring prompt and antibacterial diagnosis. Sputum samples were collected from 100 patients including 68 males and 32 females with age ranged between 16 -85 years from the beginning of October 2021 to the end of March 2022. Specimens have been collected from isolation wards at Al-Hussein Teaching Hospital in Thi-Qar province, south of Iraq from patients that were diagnosed with COVID-19 and taking preventive treatment for bacterial infections. The results have shown the most common isolates were Klebsiella pneumoniae as the pathogen registered in 20 (32.2%) of the total 62 bacterial positive cases, followed by the Candida spp. 18 (29%). The current study also has demonstrated that the bacterial isolates were varied in their resistance and sensitivity to the antibiotics. A DNA fragment encoding the open reading frame (903 bp) of Cation-efflux pump FieF was successfully shown a positive PCR band and isolated from only 10 (47.6%) isolates of K. pneumoniae isolates were named Thi-Qar1-Thi-Qar11 by conventional PCR using Cation-efflux pump FieF gene specific primer. The obtained nucleotide sequences of the Cation-efflux pump FieF from the above-mentioned Thi-Qar isolates were deposited in the GenBank under accession numbers MZ069095-MZ069104.
... The COVID-19 pandemic has further highlighted the possible role of mass transport in virus transmission given, on the one hand, the features of resistance demonstrated by SARS-CoV-2 in the external environment [11,12] and, on the other hand, the identification of a large number of viral sequences with potential viral-host interactions in the transport environment [10]. ...
Abstract 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
Background: The COVID-19 pandemic significantly disrupted forensic science, exposing vulnerabilities and introducing unprecedented challenges. Five years later, its impact persists, necessitating ongoing adaptations in forensic practice. This study examines key transformations, persistent issues, and emerging challenges in forensic science post-pandemic. Methods: A critical analysis of forensic science’s response to the pandemic was conducted, focusing on operational disruptions, methodological advancements, educational shifts, and technological integration. Results: Forensic operations faced delays due to case backlogs, restricted in-person work, and postponed court proceedings. Forensic pathology evolved with increased reliance on molecular autopsy techniques to clarify COVID-19-related deaths. Educational methods shifted toward virtual learning, prompting discussions on standardized digital training. Additionally, artificial intelligence and automation gained prominence in forensic investigations, enhancing crime scene analysis and predictive modeling. Discussion: While forensic science demonstrated adaptability, challenges remain in international collaboration, resource distribution, and professional training. The pandemic accelerated technological integration but also raised ethical and procedural concerns, particularly regarding AI applications in legal contexts. Virtual learning innovations necessitate further development to ensure competency in forensic training. Conclusions: Forensic science continues to evolve in response to post-pandemic realities. Addressing gaps in cooperation, technology implementation, and training will be crucial to strengthening the field. By assessing these changes, this study underscores forensic science’s resilience and adaptability, offering insights into its future trajectory amid ongoing challenges.
The growing concern over the transmission of pathogens, particularly in high-risk environments such as healthcare facilities and public spaces, necessitates the development of effective and sustainable antimicrobial solutions. Traditional coatings often rely on metals, which despite their efficacy, pose significant environmental and economic challenges. This study explores the potential of bio-based alkyd resins, supplemented with natural antimicrobial bioadditives, as an eco-friendly alternative to traditional antibacterial and antiviral coatings. Specifically, alkyd formulations incorporating thymol and soft resins extracted from hops were evaluated for antimicrobial and antiviral efficacy, following ISO standards (ISO 22196:2007 and ISO 21702:2019, respectively). The coating formulations showed significant activity against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus), and Influenza A (H3N2) virus, proving their potential for mitigating pathogen spread. These bio-based coatings not only reduce reliance on harmful chemicals but also align with circular economy principles by repurposing industrial by-products. This innovative approach represents a significant step toward greener antimicrobial technologies, with broad applications in healthcare, public infrastructure, and beyond, especially considering the rising zoonotic disease outbreaks.
This study aimed to investigate preparation and readiness levels of Community Isolation (CI) established as an emergency response to COVID 19 pandemic situation in Nakhon Si Thammarat province Thailand. Fifty seven CIs that matched the sample criteria were evaluated by using 3 parts of a questionnaire (Operational staff information, CI Information and CI readiness for establishment). Data was collected duringMay-October 2022, and analyzed using descriptive statistics.
The results showed that most of the CIs was organized by the Local Administrative Organizations (89. 47%). CIs were established during the COVID 19 confirm cases were sharply increased. Most CI staffs was female (64.91%), average age was 43.58 year (SD = 8.80), has a Bachelor’s degree in Health Sciences or Sciences and Technology (52.63%) and Master’s degrees is in Social Sciences (47.37%). Most of the staffs was responsible for coordinating and 64. 91% operating without an Environmental Health Experience and training. Approximately 43.86% of CIs was operated in education institutes. Most of CI investigated was categorized as small size CI (1-38 bed) that accounted for 45.95% of all CIs. More than a half of CI (74.71%) ordered the meal from outsourced food services and 92. 98% operated using Natural air ventilation. For levels of readiness, we found that overall readiness of 5 items, i. e. CIs management, location, staffs, supporting and general operation, was in high level (63.16% – 98.25%), and moderate level (1.75%–17.54%). However, we noticed that readiness of staffs was at low level for 19.3% of all CIs. Most of CIs (80.70%) had no wastewater disinfection system. In order to efficiently operate the public health emergency responses and decrease effects from the operation, the Policy makers in Ministry of Public Health, Ministry of Interior and the crisis respond commanders should allocate the qualified staffs that have knowledge and understanding in public health or environmental health to Cl in need and should set emergency response plan to all related operational units to follow according to the same standard.
Amidst the ongoing global challenge of the SARS-CoV-2 pandemic, the quest for effective antiviral medications remains paramount. This comprehensive review delves into the dynamic landscape of FDA-approved medications repurposed for COVID-19, categorized as antiviral and non-antiviral agents. Our focus extends beyond conventional narratives, encompassing vaccination targets, repurposing efficacy, clinical studies, innovative treatment modalities, and future outlooks. Unveiling the genomic intricacies of SARS-CoV-2 variants, including the WHO-designated Omicron variant, we explore diverse antiviral categories such as fusion inhibitors, protease inhibitors, transcription inhibitors, neuraminidase inhibitors, nucleoside reverse transcriptase, and non-antiviral interventions like importin α/β1-mediated nuclear import inhibitors, neutralizing antibodies, and convalescent plasma. Notably, Molnupiravir emerges as a pivotal player, now licensed in the UK. This review offers a fresh perspective on the historical evolution of COVID-19 therapeutics, from repurposing endeavors to the latest developments in oral anti-SARS-CoV-2 treatments, ushering in a new era of hope in the battle against the pandemic.
In healthcare settings, contaminated surfaces play an important role in the transmission of nosocomial pathogens potentially resulting in healthcare-associated infections (HAI). Pathogens can be transmitted directly from frequent hand-touch surfaces close to patients or indirectly by staff and visitors. HAI risk depends on exposure, extent of contamination, infectious dose (ID), virulence, hygiene practices, and patient vulnerability. This review attempts to close a gap in previous reviews on persistence/tenacity by only including articles ( n = 171) providing quantitative data on re-cultivable pathogens from fomites for a better translation into clinical settings. We have therefore introduced the new term “replication capacity” (RC). The RC is affected by the degree of contamination, surface material, temperature, relative humidity, protein load, organic soil, UV-light (sunlight) exposure, and pH value. In general, investigations into surface RC are mainly performed in vitro using reference strains with high inocula. In vitro data from studies on 14 Gram-positive, 26 Gram-negative bacteria, 18 fungi, 4 protozoa, and 37 viruses. It should be regarded as a worst-case scenario indicating the upper bounds of risks when using such data for clinical decision-making. Information on RC after surface contamination could be seen as an opportunity to choose the most appropriate infection prevention and control (IPC) strategies. To help with decision-making, pathogens characterized by an increased nosocomial risk for transmission from inanimate surfaces (“fomite-borne”) are presented and discussed in this systematic review. Thus, the review offers a theoretical basis to support local risk assessments and IPC recommendations.
This research investigates the effectiveness of distributing masks and providing counseling to local communities in preventing the spread of Covid-19. Employing a mixed-methods approach, the study utilizes a quasi-experimental design to compare outcomes between intervention and control groups. Participants from diverse communities receive masks through distribution channels and participate in counseling sessions covering Covid-19 prevention strategies. Quantitative data, including surveys on mask usage and infection rates, are complemented by qualitative data from focus group discussions and interviews to provide a comprehensive analysis. Findings indicate a significant reduction in infection rates and improvements in mask usage and community knowledge among intervention groups. Implications for public health policy and practice are discussed, highlighting the importance of multifaceted interventions and community engagement in pandemic response efforts. Limitations of the study include the quasi-experimental design and reliance on self-reported data. Overall, the research contributes to our understanding of effective strategies for mitigating Covid-19 transmission and building resilient communities in the face of pandemics.
Introduction: In the COVID-19 pandemic, the implementation of the lockdown led to the closure of dental practices. Restricting treatment to emergency patients, having to use Personal Protective Equipment and the fear of contracting the virus led to modifications in the techniques and methods used to provide efficient dental care to the patients. However, it caused a significant psychological and financial impact on the dental community. The purpose of this research was to evaluate dentists’ perceptions regarding the psychological, financial, and general impact of the COVID-19 pandemic on the reopening of their dental practices. Methods: This cross-sectional analytical study was conducted using a validated questionnaire, which was distributed among 257 dental practitioners working in Karachi through the social media app (WhatsApp®) from May 2021 to May 2022. The questionnaire included four sections and 26 items, recording data for demographics, psychological effects on resumption of dental practices, workplace disinfection, and precautionary measures along financial impacts. Data were analyzed using SPSS, version 21.0. p-value ≤ 0.05 was taken as statistically significant Results: A total of 200 filled questionnaires were received, making the response rate 77%. The majority of respondents were females (67%). More than half of the respondents (55.5%) were working in dental OPDs. Most participants affirmed that they did not have a COVID-19 screening area nor patient triage was being done in dental OPDs. Closure of dental practices caused financial problems for all dental practitioners, more specifically for those that were associated with both public and private types of practices (84.9%). The majority of the dentists in private practice (94.4%) declared that their workplaces were being disinfected, while 47.7% of dental practitioners working in the dental OPD affirmed that they had enough financial stability to keep using Personal Protective Equipment. Approximately 64.9% of professionals practicing in dental OPDs and 33.3% in private practice believed that the reopening of dental practices was responsible for the re-spread of the coronavirus Conclusion: Significant anxiety and stress related to COVID-19 were seen among dental practitioners. Some CDC-recommended guidelines such as the use of Personal Protective Equipment were being implemented whereas COVID-19 screening and patient triage were found deficient.
Enveloped viruses pose a critical health threat to human beings. Photodynamic inactivation shows promise but requires a relatively long time of irradiation or a high power intensity. Meanwhile, the unclear role of reactive oxygen species (ROS) in inactivation hampers the development of effective antivirus equipment. Here, we present that protoporphyrin IX-loaded silica nanoparticles show high efficiency in inactivating enveloped viruses. Representative enveloped viruses, including herpes simplex virus 1, vesicular stomatitis virus, and pseudoviruses SARS-CoV-2, were almost fully inactivated under <16 min of irradiation of a halogen tungsten lamp. By a quantitative polymerase chain reaction technique, we found that the viruses lost their ability to bind cells after the photoinactivation. The mechanistic study further showed that the nanoparticle-based photodynamic effect disrupted the receptor-binding proteins on the envelope rather than destroying the whole virus structure by ROS. Our results suggest a highly efficient approach to disinfecting enveloped viruses and may shed light on designing photodynamic materials for breaking spreading chains in epidemics.
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.
Effective sampling for SARS-CoV-2 is a common approach for monitoring disinfection efficacy and effective environmental surveillance. This study evaluated sampling efficiency and limits of detection (LOD) 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 six inch square coupons composed of four materials: stainless steel (SS), Acrylonitrile Butadiene Styrene plastic (ABS), 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.
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.
Abstract Microbial contamination of plastic surfaces is a significant source of hospital‐acquired infections. To produce antimicrobial surfaces, chlorhexidine was attached to nitrided acrylonitrile butadiene styrene (ABS). The uniformity of chlorhexidine distribution on the plastic surfaces was revealed by time‐of‐flight secondary ion mass spectrometry (TOF‐SIMS) imaging. Its antimicrobial efficacy was established against model pathogenic Gram‐positive and Gram‐negative bacteria, fungi, and viruses. The stability of the bonded chlorhexidine was evaluated via a leaching test. The surfaces rapidly killed microbes: no viable colonies of Escherichia coli, Staphylococcus aureus, or Candida albicans were recoverable after 45 minutes. It was effective against SARS‐COV‐2, with no viable virions found after 30 minutes. Additionally, the surfaces were as effective in killing chlorhexidine‐resistant strains of bacteria as they were in killing naïve strains. The surface was stable; after 2 weeks of leaching, no detectable chlorhexidine was found in the leachate. We believe that the technology is widely applicable to prevent the spread of fomite infection.
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.
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.
While the transmission of virus SARS‐CoV‐2 via food is rare, some Chinese food retailers are considering a Covid‐19‐tested food label. However, how consumers may support such a label is unknown. We quantify Chinese consumers’ willingness to pay (WTP) for food carrying a Covid‐19‐tested label using an online choice experiment. We find that the WTPs for such a label are always positive for all food products considered. The amount of WTP depends on the entities authenticating the labels, country of origin of the food, and consumers’ socio‐demographic status. Contrary to expectation, the knowledge on Covid‐19 does not affect consumer preferences for the Covid‐19‐tested food labels. Our benefit and cost analysis suggests a possible large benefit of creating and administering a Covid‐19‐tested food label. This study provides insights for policymakers, global food manufacturers, and retailers to create marketing strategies to alleviate consumer food safety concerns associated with Covid‐19.
Evidence suggests that SARS-CoV-2, as well as other coronaviruses, can be dispersed and potentially transmitted by aerosols directly or via ventilation systems. We therefore investigated ventilation openings in one COVID-19 ward and central ducts that expel indoor air from three COVID-19 wards at Uppsala University Hospital, Sweden, during April and May 2020. Swab samples were taken from individual ceiling ventilation openings and surfaces in central ducts. Samples were subsequently subjected to rRT-PCR targeting the N and E genes of SARS-CoV-2. Central ventilation HEPA filters, located several stories above the wards, were removed and portions analyzed in the same manner. In two subsequent samplings, SARS-CoV-2 N and E genes were detected in seven and four out of 19 room vents, respectively. Central ventilation HEPA exhaust filters from the ward were found positive for both genes in three samples. Corresponding filters from two other, adjacent COVID-19 wards were also found positive. Infective ability of the samples was assessed by inoculation of susceptible cell cultures but could not be determined in these experiments. Detection of SARS-CoV-2 in central ventilation systems, distant from patient areas, indicate that virus can be transported long distances and that droplet transmission alone cannot reasonably explain this, especially considering the relatively low air change rates in these wards. Airborne transmission of SARS-CoV-2 must be taken into consideration for preventive measures.
This study calculates and elucidates the minimum size of respiratory particles that are potential carriers of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); furthermore, it evaluates the aerosol generation potential of SARS-CoV-2. The calculations are based on experimental results and theoretical models. In the case of maximum viral-loading derived from experimental data of COVID-19 patients, 7.18 × 10-4% of a respiratory fluid particle from a COVID-19 patient is occupied by SARS-CoV-2. Hence, the minimum size of a respiratory particle that can contain SARS-CoV-2 is calculated to be approximately 4.7 μm. The minimum size of the particles can decrease due to the evaporation of water on the particle surfaces. There are limitations to this analysis: (a) assumption that the viruses are homogeneously distributed in respiratory fluid particles and (b) considering a gene copy as a single virion in unit conversions. However, the study shows that high viral loads can decrease the minimum size of respiratory particles containing SARS-CoV-2, thereby increasing the probability of aerosol generation of the viruses. The aerosol generation theory created in this study for COVID-19 has the potential to be applied to other contagious diseases that are caused by respiratory infectious microorganisms.
Objectives A number of studies have shown that the
airborne transmission route could spread some viruses
over a distance of 2 meters from an infected person.
An epidemic model based only on respiratory droplets
and close contact could not fully explain the regional
differences in the spread of COVID-19 in Italy. On March
16th 2020, we presented a position paper proposing a
research hypothesis concerning the association between
higher mortality rates due to COVID-19 observed in
Northern Italy and average concentrations of PM10
exceeding a daily limit of 50 µg/m3.
Methods To monitor the spreading of COVID-19 in
Italy from February 24th to March 13th (the date of the
Italian lockdown), official daily data for PM10 levels were
collected from all Italian provinces between February 9th
and February 29th, taking into account the maximum lag
period (14 days) between the infection and diagnosis. In
addition to the number of exceedances of the daily limit
value of PM
10, we also considered population data and
daily travelling information for each province.
Results Exceedance of the daily limit value of PM10
appears to be a significant predictor of infection in
univariate analyses (p<0.001). Less polluted provinces had
a median of 0.03 infections over 1000 residents, while the
most polluted provinces showed a median of 0.26 cases.
Thirty-nine out of 41 Northern Italian provinces resulted in
the category with the highest PM10 levels, while 62 out of
66 Southern provinces presented low PM10 concentrations
(p<0.001). In Milan, the average growth rate before the
lockdown was significantly higher than in Rome (0.34
vs 0.27 per day, with a doubling time of 2.0 days vs 2.6,
respectively), thus suggesting a basic reproductive number
R
0>6.0, comparable with the highest values estimated for
China.
Conclusion A significant association has been found
between the geographical distribution of daily PM10
exceedances and the initial spreading of COVID-19 in the
110 Italian provinces
Objective:
SARS-CoV-2 can reportedly exist on inanimate surfaces for a long duration, but there is limited data available from Italian COVID-19 hospital wards, especially for non-intensive care units hosting patients that do not require mechanical ventilation. Identification of the extent of environmental contamination can help in understanding possible virus transmission routes, limit hospital infections and protect healthcare workers. Thus, we investigated virus contamination on surfaces of the acute COVID-19 ward of an Italian hospital.
Materials and methods:
Ward surfaces, including four points inside and six points outside the patients' rooms were sampled by swabs, seven hours after routine sanitation. To minimize the risk of underestimation of virus detection, two different sensitive molecular methods were used comparatively, and specific internal controls were added to enhance the efficiency of all the analysis steps.
Results:
SARS-CoV-2 contamination was detected in only three out of all the collected samples, i.e., on two floors and one-bathroom sink, likely reflecting aerosol and saliva contamination, respectively. The overall level of contamination was low, and the floors exhibited a very low level of SARS-CoV-2 presence, evidenced by only one of the two methods used.
Conclusions:
The existence of SARS-CoV-2 on hospital surfaces may be limited, although it was reported to persist for a longer duration on surfaces under controlled laboratory conditions. Thus, effective transmission of SARS-CoV-2 by surfaces/fomites within the hospital ward may be a rare event. However, the results highlight the importance of assessing method sensitivity and including controls when investigating low-level virus contamination so as to avoid the risk of underestimation of virus presence.
Airborne transmission is a recognized pathway of contagion; however, it is rarely quantitatively evaluated. The numerous outbreaks that have occurred during the SARS-CoV-2 pandemic are putting a demand on researchers to develop approaches capable of both predicting contagion in closed environments (predictive assessment) and analyzing previous infections (retrospective assessment).
This study presents a novel approach for quantitative assessment of the individual infection risk of susceptible subjects exposed in indoor microenvironments in the presence of an asymptomatic infected SARS-CoV-2 subject. The application of a Monte Carlo method allowed the risk for an exposed healthy subject to be evaluated or, starting from an acceptable risk, the maximum exposure time. We applied the proposed approach to four distinct scenarios for a prospective assessment, highlighting that, in order to guarantee an acceptable risk of 10⁻³ for exposed subjects in naturally ventilated indoor environments, the exposure time could be well below one hour. Such maximum exposure time clearly depends on the viral load emission of the infected subject and on the exposure conditions; thus, longer exposure times were estimated for mechanically ventilated indoor environments and lower viral load emissions. The proposed approach was used for retrospective assessment of documented outbreaks in a restaurant in Guangzhou (China) and at a choir rehearsal in Mount Vernon (USA), showing that, in both cases, the high attack rate values can be justified only assuming the airborne transmission as the main route of contagion. Moreover, we show that such outbreaks are not caused by the rare presence of a superspreader, but can be likely explained by the co-existence of conditions, including emission and exposure parameters, leading to a highly probable event, which can be defined as a “superspreading event”.
COVID-19 is caused by a novel SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2). During the COVID-19 epidemic, when people are infected with the virus, they can transmit the virus onto paper or coin money through touch and droplets, potentially making any physical currency a carrier of the virus. Although there is no report confirming that people can become infected with viruses by cash circulation, relevant research on the survival of viruses on solid surfaces supports this hypothesis. Mobile payments can help individuals avoid coming in direct contact with any paper or coin money. Therefore, we strongly recommend the promotion of mobile payments during the COVID-19 epidemic.
The coronavirus disease 2019 (COVID‐19) pandemic has heightened awareness of aerosol generation by human expiratory events and their potential role in viral respiratory disease transmission. Concerns over high Severe Acute Respiratory Syndrome Coronavirus 2 (SARS‐CoV‐2) viral burden of mucosal surfaces has raised questions about the aerosol generating potential and dangers of many otorhinolaryngologic procedures. However, the risks of aerosol generation and associated viral transmission by droplet or airborne routes for many otorhinolaryngology procedures are largely unknown. Indoor aerosol and droplet viral respiratory transmission risk is influenced by four factors: 1) aerosol or droplet properties, 2) indoor airflow, 3) virus‐specific factors, and 4) host‐specific factors. Here we elaborate on known aerosol versus droplet properties, indoor airflow, and aerosol generating events to provide context for risks of aerosol infectious transmission. We also provide simple but typically effective measures for mitigating the spread and inhalation of viral aerosols in indoor settings. Understanding principles of infectious transmission, aerosol and droplet generation, as well as concepts of indoor airflow, will aide in the integration of new data on SARS‐CoV‐2 transmission and activities that can generate aerosol to best inform on the need for escalation or de‐escalation from current societal and institutional guidelines for protection during aerosol generating procedures.
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Evidence suggests that SARS-CoV-2 can be dispersed and potentially transmitted by aerosols, directly or via ventilation systems. We report detection of SARS-CoV-2 RNA in COVID-19 ward ceiling vent openings as well as in ventilation exhaust filters and central ducts up to at least 56 meters from patient areas. As this ventilation system provides low air flow, we propose that viral particles may be readily dispersed in air over vast distances and that further investigations of infectivity of airborne SARS-CoV-2 must be performed.
Mitigating the transmission of SARS-CoV-2 in clinical settings and public spaces is critically important to reduce the number of COVID-19 cases while effective vaccines and therapeutics are under development. SARS-CoV-2 transmission is thought to primarily occur through direct person-to-person transfer of infectious respiratory droplets or through aerosol-generating medical procedures. However, contact with contaminated surfaces may also play a significant role. In this context, understanding the factors contributing to SARS-CoV-2 persistence on surfaces will enable a more accurate estimation of the risk of contact transmission and inform mitigation strategies. To this end, we have developed a simple mathematical model that can be used to estimate virus decay on nonporous surfaces under a range of conditions and which may be utilized operationally to identify indoor environments in which the virus is most persistent.
Although the unprecedented efforts the world has been taking to control the spread of the human coronavirus disease (COVID-19) and its causative etiology [Severe Acute Respiratory Syndrome- Coronavirus-2 (SARS-CoV-2)], the number of confirmed cases has been increasing drastically. Therefore, there is an urgent need for devising more efficient preventive measures, to limit the spread of the infection until an effective treatment or vaccine is available. The preventive measures depend mainly on the understanding of the transmission routes of this virus, its environmental stability, and its persistence on common touch surfaces. Due to the very limited knowledge about SARS-CoV-2, we can speculate its stability in the light of previous studies conducted on other human and animal coronaviruses. In this review, we present the available data on the stability of coronaviruses (CoVs), including SARS-CoV-2, from previous reports to help understand its environmental survival. According to available data, possible airborne transmission of SARS-CoV-2 has been suggested. SARS-CoV-2 and other human and animal CoVs have remarkably short persistence on copper, latex, and surfaces with low porosity as compared to other surfaces like stainless steel, plastics, glass, and highly porous fabrics. It has also been reported that SARS-CoV-2 is associated with diarrhea and that it is shed in the feces of COVID-19 patients. Some CoVs show persistence in human excrement,
sewage, and waters for a few days. These findings suggest a possible risk of fecal-oral, foodborne, and waterborne transmission of SARS-CoV-2 in developing countries that often use sewage-polluted waters in irrigation and have poor water treatment systems. CoVs survive longer in the environment at lower temperatures and lower relative humidity. It has been suggested that large numbers of COVID-19 cases are associated with cold and dry climates in temperate regions of the world and that seasonality of the virus spread is suspected.
The COVID-19 outbreak has rapidly progressed worldwide finding the health system, scientists and society unprepared to face a little-known, fast spreading, and extremely deadly virus. Italy is one of the countries hardest hit by the pandemic, resulting in healthcare facilities bearing heavy burdens and severe restrictive measures. Despite efforts to clarify the virus transmission, especially in indoor scenarios, several aspects of SARS-CoV-2 spread are still rudimentary. This study evaluated the contamination of the air and surfaces by SARS-CoV-2 RNA in the COVID-19 isolation ward of a hospital in Milan, Italy. A total of 42 air and surface samples were collected inside five different zones of the ward including contaminated (COVID-19 patients' area), semi-contaminated (undressing room), and clean areas. SARS-CoV-2 RNA detection was performed using real time reverse transcription polymerase chain reaction. Overall, 24.3% of swab samples were positive, but none of these were collected in the clean area. Thus, the positivity rate was higher in contaminated (35.0%) and semi-contaminated (50.0%) areas than in clean areas (0.0%; P<0.05). The most contaminated surfaces were hand sanitizer dispensers (100.0%), medical equipment (50.0%), medical equipment touch screens (50.0%), shelves for medical equipment (40.0%), bedrails (33.3%), and door handles (25.0%). All the air samples collected from the contaminated area, namely the intensive care unit and corridor, were positive while viral RNA was not detected in either semi-contaminated or clean areas. These results showed that environmental contamination did not involve clean areas, but the results also support the need for strict disinfection, hand hygiene and protective measures for healthcare workers as well as the need for airborne isolation precautions.
In recent years, a number of epidemiological studies have demonstrated that exposure to air pollution is associated with several adverse outcomes, such as acute lower respiratory infections, chronic obstructive pulmonary disease, asthma, cardiovascular diseases, and lung cancer among other serious diseases. Air pollutants such as sulfur oxides, nitrogen oxides, carbon monoxide and dioxide, particulate matter (PM), ozone and volatile organic compounds (VOCs) are commonly found at high levels in big cities and/or in the vicinity of different chemical industries. An association between air concentrations of these pollutants and human respiratory viruses interacting to adversely affect the respiratory system has been also reported. The present review was aimed at assessing the potential relationship between the concentrations of air pollutants on the airborne transmission of SARS-CoV-2 and the severity of COVID-19 in patients infected by this coronavirus. The results of most studies here reviewed suggest that chronic exposure to certain air pollutants leads to more severe and lethal forms of COVID-19 and delays/complicates the recovery of patients of this disease.
In December, 2019, a highly infectious and rapidly spreading new pneumonia of unknown cause was reported to the Chinese WHO Country Office. A cluster of these cases had appeared in Wuhan, a city in the Hubei Province of China. These infections were found to be caused by a new coronavirus which was given the name “2019 novel coronavirus” (2019-nCoV). It was later renamed “severe acute respiratory syndrome coronavirus 2,” or SARS-CoV-2 by the International Committee on Taxonomy of Viruses on February 11, 2020. It was named SARS-CoV-2 due to its close genetic similarity to the coronavirus which caused the SARS outbreak in 2002 (SARS-CoV-1). The aim of this review is to provide information, primarily to the food industry, regarding a range of biocides effective in eliminating or reducing the presence of coronaviruses from fomites, skin, oral/nasal mucosa, air, and food contact surfaces. As several EPA approved sanitizers against SARS-CoV-2 are commonly used by food processors, these compounds are primarily discussed as much of the industry already has them on site and is familiar with their application and use. Specifically, we focused on the effects of alcohols, povidone iodine, quaternary ammonium compounds, hydrogen peroxide, sodium hypochlorite (NaOCl), peroxyacetic acid (PAA), chlorine dioxide, ozone, ultraviolet light, metals, and plant-based antimicrobials. This review highlights the differences in the resistance or susceptibility of different strains of coronaviruses, or similar viruses, to these antimicrobial agents.
Sars-cov-2 virus (Covid-19) is a member of the coronavirus family and is responsible for the pandemic recently declared by the World Health Organization. A positive correlation has been observed between the spread of the virus and air pollution, one of the greatest challenges of our millennium. Covid-19 could have an air transmission and atmospheric particulate matter (PM) could create a suitable environment for transporting the virus at greater distances than those considered for close contact. Moreover, PM induces inflammation in lung cells and exposure to PM could increase the susceptibility and severity of the Covid-19 patient symptoms. The new coronavirus has been shown to trigger an inflammatory storm that would be sustained in the case of pre-exposure to polluting agents. In this review, we highlight the potential role of PM in the spread of Covid-19, focusing on Italian cities whose PM daily concentrations were found to be higher than the annual average allowed during the months preceding the epidemic. Furthermore, we analyze the positive correlation between the virus spread, PM, and angiotensin-converting enzyme 2 (ACE2), a receptor involved in the entry of the virus into pulmonary cells and inflammation.
The COVID-19 epidemic, caused by the SARS-CoV-2 virus, has resulted in 3352 deaths in China as of April 12, 2020. This study aimed to investigate the associations between particulate matter (PM) concentrations and the case fatality rate (CFR) of COVID-19 in 49 Chinese cities, including the epicenter of Wuhan. We used the Global Moran's I to analyze spatial distribution and autocorrelation of CFRs, and then we used multivariate linear regression to analyze the associations between PM2.5 and PM10 concentrations and COVID-19 CFR. We found positive associations between PM pollution and COVID-19 CFR in cities both inside and outside Hubei Province. For every 10 μg/m³ increase in PM2.5 and PM10 concentrations, the COVID-19 CFR increased by 0.24% (0.01%–0.48%) and 0.26% (0.00%–0.51%), respectively. PM pollution distribution and its association with COVID-19 CFR suggests that exposure to such may affect COVID-19 prognosis.
This study aimed to determine the presence of SARS-CoV-2 on surfaces frequently touched by COVID-19 patients, and assess the scope of contamination and transmissibility in facilities where the outbreaks occurred. In the course of this epidemiological investigation, a total of 80 environmental specimens were collected from 6 hospitals (68 specimens) and 2 "mass facilities" (6 specimens from a rehabilitation center and 6 specimens from an apartment building complex). Specific reverse transcriptase-polymerase chain reaction targeting of RNA-dependent RNA polymerase, and envelope genes, were used to identify the presence of this novel coronavirus. The 68 specimens from 6 hospitals (A, B, C, D, E, and G), where prior disinfection/cleaning had been performed before environmental sampling, tested negative for SARS-CoV-2. However, 2 out of 12 specimens (16.7%) from 2 "mass facilities" (F and H), where prior disinfection/cleaning had not taken place, were positive for SARS-CoV-2 RNA polymerase, and envelope genes. These results suggest that prompt disinfection and cleaning of potentially contaminated surfaces is an effective infection control measure. By inactivating SARS-CoV-2 with disinfection/cleaning the infectivity and transmission of the virus is blocked. This investigation of environmental sampling may help in the understanding of risk assessment of the COVID-19 outbreak in "mass facilities" and provide guidance in using effective disinfectants on contaminated surfaces.
Aerosols represent a potential route of transmission of COVID-19. This study examined the effect of simulated sunlight, relative humidity, and suspension matrix on the stability of SARS-CoV-2 in aerosols. Both simulated sunlight and matrix significantly affected the decay rate of the virus. Relative humidity alone did not affect the decay rate; however, minor interactions between relative humidity and the other factors were observed. Decay rates in simulated saliva, under simulated sunlight levels representative of late winter/early fall and summer were 0.121±0.017 min-1 (90% loss: 19 minutes) and 0.379±0.072 min-1 (90% loss: 6 minutes), respectively. The mean decay rate without simulated sunlight across all relative humidity levels was 0.008±0.011 min-1 (90% loss: 125 minutes). These results suggest that the potential for aerosol transmission of SARS-CoV-2 may be dependent on environmental conditions, particularly sunlight. These data may be useful to inform mitigation strategies to minimize the potential for aerosol transmission.
The outbreak of coronavirus disease 2019 (COVID-19), caused by the virus SARS-CoV-2, has been rapidly increasing in the United States. Boroughs of New York City, including Queens county, turn out to be the epicenters of this infection. According to the data provided by the New York State Department of Health, most of the cases of new COVID-19 infections in New York City have been found in the Queens county where 42,023 people have tested positive, and 3221 people have died as of 20 April 2020. Person-to-person transmission and travels were implicated in the initial spread of the outbreaks, but factors related to the late phase of rapidly spreading outbreaks in March and April are still uncertain. A few previous studies have explored the links between air pollution and COVID-19 infections, but more data is needed to understand the effects of short-term exposures of air pollutants and meteorological factors on the spread of COVID-19 infections, particularly in the U.S. disease epicenters. In this study, we have focused on ozone and PM2.5, two major air pollutants in New York City, which were previously found to be associated with respiratory viral infections. The aim of our regression modeling was to explore the associations among ozone, PM2.5, daily meteorological variables (wind speed, temperature, relative humidity, absolute humidity, cloud percentages, and precipitation levels), and COVID-19 confirmed new cases and new deaths in Queens county, New York during March and April 2020. The results from these analyses showed that daily average temperature, daily maximum eight-hour ozone concentration, average relative humidity, and cloud percentages were significantly and positively associated with new confirmed cases related to COVID-19; none of these variables showed significant associations with new deaths related to COVID-19. The findings indicate that short-term exposures to ozone and other meteorological factors can influence COVID-19 transmission and initiation of the disease, but disease aggravation and mortality depend on other factors.
The WHO has declared COVID-19 illness a global health concern which is caused by 2019-nCoV, causing severe respiratory tract infections in humans. Transmissibility among individual to individual have been reported through droplets and probably also via contaminated surfaces and hands.
Human coronaviruses can persist on inanimate surfaces such as plastic, glass, fibers and metals up to nine days. 2019-nCoV remains infectious in air for 3 h and on inanimate surfaces such as cardboard, copper, plastic and steel up to 24, 4, 72 and 48 h respectively. Disinfectant activity of various biocidal agents against coronaviruses like ethanol (62–71%), sodium hypochlorite (0.1%) and hydrogen peroxide (0.5%) can be regarded effective against 2019-nCoV as well. As no vaccine and antiviral therapies have been discovered for 2019-nCoV, prevention of further spread will viable option to control the ongoing and future outbreaks.
A recent report described a sharp increase in calls to poison centers related to exposures to cleaners and disinfectants since the onset of the coronavirus disease 2019 (COVID-19) pandemic (1). However, data describing cleaning and disinfection practices within household settings in the United States are limited, particularly concerning those practices intended to prevent transmission of SARS-CoV-2, the virus that causes COVID-19. To provide contextual and behavioral insight into the reported increase in poison center calls and to inform timely and relevant prevention strategies, an opt-in Internet panel survey of 502 U.S. adults was conducted in May 2020 to characterize knowledge and practices regarding household cleaning and disinfection during the COVID-19 pandemic. Knowledge gaps were identified in several areas, including safe preparation of cleaning and disinfectant solutions, use of recommended personal protective equipment when using cleaners and disinfectants, and safe storage of hand sanitizers, cleaners, and disinfectants. Thirty-nine percent of respondents reported engaging in nonrecommended high-risk practices with the intent of preventing SARS-CoV-2 transmission, such as washing food products with bleach, applying household cleaning or disinfectant products to bare skin, and intentionally inhaling or ingesting these products. Respondents who engaged in high-risk practices more frequently reported an adverse health effect that they believed was a result of using cleaners or disinfectants than did those who did not report engaging in these practices. Public messaging should continue to emphasize evidence-based, safe practices such as hand hygiene and recommended cleaning and disinfection of high-touch surfaces to prevent transmission of SARS-CoV-2 in household settings (2). Messaging should also emphasize avoidance of high-risk practices such as unsafe preparation of cleaning and disinfectant solutions, use of bleach on food products, application of household cleaning and disinfectant products to skin, and inhalation or ingestion of cleaners and disinfectants.
The novel coronavirus disease (COVID-19) is a highly pathogenic, transmittable and invasive pneumococcal disease caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), which emerged in December 2019 and January 2020 in Wuhan city, Hubei province, China and fast spread later on the middle of February 2020 in the Northern part of Italy and Europe.
This study investigates the correlation between the degree of accelerated diffusion and lethality of COVID-19 and the surface air pollution in Milan metropolitan area, Lombardy region, Italy. Daily average concentrations of inhalable particulate matter (PM) in two size fractions PM2.5, PM10 and maxima PM10 ground level atmospheric pollutants together air quality and climate variables (daily average temperature, relative humidity, wind speed, atmospheric pressure field and Planetary Boundary Layer-PBL height) collected during 1 January–30 April 2020 were analyzed. In spite of being considered primarily transmitted by indoor bioaerosols droplets and infected surfaces, or direct human-to-human personal contacts, it seems that high levels of urban air pollution, weather and specific climate conditions have a significant impact on the increased rates of confirmed COVID-19 Total number, Daily New and Total Deaths cases, possible attributed not only to indoor but also to outdoor airborne bioaerosols distribution. Our analysis demonstrates the strong influence of daily averaged ground levels of particulate matter concentrations, positively associated with average surface air temperature and inversely related to air relative humidity on COVID-19 cases outbreak in Milan. Being a novel pandemic coronavirus (SARS-CoV-2) version, COVID-19 might be ongoing during summer conditions associated with higher temperatures and low humidity levels. Presently is not clear if this protein “spike” of the new coronavirus COVID-19 is involved through attachment mechanisms on indoor or outdoor airborne aerosols in the infectious agent transmission from a reservoir to a susceptible host in some agglomerated urban areas like Milan is.
Background
The burden of COVID-19 was extremely severe in Northern Italy, an area characterized by high concentrations of particulate matter (PM), which is known to negatively affect human health. Consistently with evidence already available for other viruses, we initially hypothesized the possibility of SARS-CoV-2 presence on PM, and we performed a first experiment specifically aimed at confirming or excluding this research hyphotesys.
Methods
We have colelcted 34 PM10 samples in Bergamo area (the epicenter of the Italian COVID-19 epidemic) by using two air samplers over a continuous 3-weeks period. Filters were properly stored and underwent RNA extraction and amplification according to WHO protocols in two parallel blind analyses performed by two different authorized laboratories. Up to three highly specific molecular marker genes (E, N, and RdRP) were used to test the presence of SARS-CoV-2 RNA on particulate matter.
Results
The first test showed positive results for gene E in 15 out of 16 samples, simultaneously displaying positivity also for RdRP gene in 4 samples. The second blind test got 5 additional positive results for at least one ofthe three marker genes. Overall, we tested 34 RNA extractions for the E, N and RdRP genes, reporting 20 positive results for at least one of the three marker genes, with positivity separately confirmed for all the three markers. Control tests to exclude false positivities were successfully accomplished.
Conclusion
This is the first evidence that SARS-CoV-2 RNA can be present on PM, thus suggesting a possible use as indicator of epidemic recurrence.
Understanding the particle size distribution in the air and patterns of environmental contamination of SARS-CoV-2 is essential for infection prevention policies. Here we screen surface and air samples from hospital rooms of COVID-19 patients for SARS-CoV-2 RNA. Environmental sampling is conducted in three airborne infection isolation rooms (AIIRs) in the ICU and 27 AIIRs in the general ward. 245 surface samples are collected. 56.7% of rooms have at least one environmental surface contaminated. High touch surface contamination is shown in ten (66.7%) out of 15 patients in the first week of illness, and three (20%) beyond the first week of illness (p = 0.01, χ2 test). Air sampling is performed in three of the 27 AIIRs in the general ward, and detects SARS-CoV-2 PCR-positive particles of sizes >4 µm and 1–4 µm in two rooms, despite these rooms having 12 air changes per hour. This warrants further study of the airborne transmission potential of SARS-CoV-2. Here, the authors sample air and surfaces in hospital rooms of COVID-19 patients, detect SARS-CoV-2 RNA in air samples of two of three tested airborne infection isolation rooms, and find surface contamination in 66.7% of tested rooms during the first week of illness and 20% beyond the first week of illness.
During the rapid rise in COVID-19 illnesses and deaths globally, and notwithstanding recommended precautions, questions are voiced about routes of transmission for this pandemic disease. Inhaling small airborne droplets is probable as a third route of infection, in addition to more widely recognized transmission via larger respiratory droplets and direct contact with infected people or contaminated surfaces. While uncertainties remain regarding the relative contributions of the different transmission pathways, we argue that existing evidence is sufficiently strong to warrant engineering controls targeting airborne transmission as part of an overall strategy to limit infection risk indoors. Appropriate building engineering controls include sufficient and effective ventilation, possibly enhanced by particle filtration and air disinfection, avoiding air recirculation and avoiding overcrowding. Often, such measures can be easily implemented and without much cost, but if only they are recognised as significant in contributing to infection control goals. We believe that the use of engineering controls in public buildings, including hospitals, shops, offices, schools, kindergartens, libraries, restaurants, cruise ships, elevators, conference rooms or public transport, in parallel with effective application of other controls (including isolation and quarantine, social distancing and hand hygiene), would be an additional important measure globally to reduce the likelihood of transmission and thereby protect healthcare workers, patients and the general public.
Objectives
To detect possible SARS-CoV-2 RNA contamination of inanimate surfaces in areas at high risk of aerosol formation by patients with COVID-19.
Methods
Sampling was performed in the emergency unit and the sub-intensive care ward. SARS-CoV-2 RNA was extracted from swabbed surfaces and objects and subjected to real-time reverse transcriptase–polymerase chain reaction (RT-PCR) targeting RNA-dependent RNA polymerase and E genes. Virus isolation from positive samples was attempted in vitro on Vero E6 cells.
Results
Twenty-six samples were collected and only two were positive for low-level SARS-CoV-2 RNA, both collected on the external surface of Continuous Positive Airway Pressure (CPAP) helmets. All transport media were inoculated onto susceptible cells, however, none induced a cytopathic effect on day 7 of culture.
Conclusions
Even though daily contact with inanimate surfaces and patient fomites in contaminated areas may be a medium of infection, our data obtained in real life conditions suggest that it might be less extensive than hitherto recognized.
Previous studies have demonstrated that SARS-CoV-2 is stable on surfaces for extended periods under indoor conditions. In the present study, simulated sunlight rapidly inactivated SARS-CoV-2 suspended in either simulated saliva or culture media and dried on stainless steel coupons. Ninety percent of infectious virus was inactivated every 6.8 minutes in simulated saliva and every 14.3 minutes in culture media when exposed to simulated sunlight representative of the summer solstice at 40oN latitude at sea level on a clear day. Significant inactivation also occurred, albeit at a slower rate, under lower simulated sunlight levels. The present study provides the first evidence that sunlight may rapidly inactivate SARS-CoV-2 on surfaces, suggesting that persistence, and subsequently exposure risk, may vary significantly between indoor and outdoor environments. Additionally, these data indicate that natural sunlight may be effective as a disinfectant for contaminated non-porous materials.
On March 11th 2020, the World Health Organization (WHO) declared the coronavirus disease (COVID‐19) caused by severe acute respiratory syndrome coronavirus (SARS‐CoV‐2) as a pandemic. Until an effective treatment or a vaccine is developed, the current recommendations are to contain the disease, and control its transmission. It is now clear that the primary mode of SARS‐CoV‐2 transmission is aerosol/droplet spread, and by contacting virus contaminated surfaces acting as fomites (inanimate vectors). Furthermore, recent data indicate that the live virus particles are present in saliva, and, more alarmingly, asymptomatic individuals may transmit the infection. By virtue of the nature of the practice of dentistry where intrinsically, a high volume of aerosols are produced, as well as the close proximity of dentists and patients during treatment, dentists and allied health staff are considered the highest risk health professional group for acquiring SARS‐CoV‐2 during patient management. Therefore, several organizations and specialty associations have proposed guidelines and recommendations for limiting the transmission of SARS‐COV‐2 from carriers to dentists and vice versa. This paper aims to provide a review of these guidelines, and concludes with a brief look at how the practice of dentistry may be impacted by COVID‐19, in the post‐pandemic era.
COVID-19 is the name of the disease supposedly manifested in December 2019 from Wuhan, because of virus named as SARS-CoV-2. Now this disease has spread to almost all other parts of the world. COVID-19 pandemic has various reasons for its dramatic worldwide increase. Here, we have studied Coronavirus sustainability on various surfaces. Various disinfectants and their roles are discussed from the available literature. The infection capabilities of SARS-CoV-1 and SARS-CoV-2 for different materials are discussed and finally studies infection decay for SARS-CoV-1 and SARS-CoV-2.
Recently, due to the coronavirus pandemic, many guidelines and anti-contagion strategies continue to report unclear information about the persistence of coronavirus disease 2019 (COVID-19) in the environment. This certainly generates insecurity and fear in people, with an important psychological component that is not to be underestimated at this stage of the pandemic. The purpose of this article is to highlight all the sources currently present in the literature concerning the persistence of the different coronaviruses in the environment as well as in medical and dental settings. As this was a current study, there are still not many sources in the literature, and scientific strategies are moving towards therapy and diagnosis, rather than knowing the characteristics of the virus. Such an article could be an aid to summarize virus features and formulate new guidelines and anti-spread strategies.
A number of nations were forced to declare a total shutdown due to COVID-19 infection, as extreme measure to cope with dramatic impact of the pandemic, with remarkable consequences both in terms of negative health outcomes and economic loses. However, in many countries a “Phase-2” is approaching and many activities will re-open soon, although with some differences depending on the severity of the outbreak experienced and SARS-COV-2 estimated diffusion in the general population. At the present, possible relapses of the epidemic cannot be excluded until effective vaccines or immunoprophylaxis with human recombinant antibodies will be properly set up and commercialized. COVD-19-related quarantines have triggered serious social challenges, so that decision makers are concerned about the risk of wasting all the sacrifices imposed to the people in these months of quarantine. The availability of possible early predictive indicators of future epidemic relapses would be very useful for public health purposes, and could potentially prevent the suspension of entire national economic systems. On 16 March, a Position Paper launched by the Italian Society of Environmental Medicine (SIMA) hypothesized for the first time a possible link between the dramatic impact of COVID-19 outbreak in Northern Italy and the high concentrations of particulate matter (PM10 and PM2.5) that characterize this area, along with its well-known specific climatic conditions. Thereafter, a survey carried out in the U.S. by the Harvard School of Public Health suggested a strong association between increases in particulate matter concentration and mortality rates due to COVID-19. The presence of SARS-COV-2 RNA on the particulate matter of Bergamo, which is not far from Milan and represents the epicenter of the Italian epidemic, seems to confirm (at least in case of atmospheric stability and high PM concentrations, as it usually occurs in Northern Italy) that the virus can create clusters with the particles and be carried and detected on PM10. Although no assumptions can be made concerning the link between this first experimental finding and COVID-19 outbreak progression or severity, the presence of SARS-COV-2 RNA on PM10 of outdoor air samples in any city of the world could represent a potential early indicator of COVID-19 diffusion. Searching for the viral genome on particulate matter could therefore be explored among the possible strategies for adopting all the necessary preventive measures before future epidemics start.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly contagious virus that can transmit through respiratory droplets, aerosols, or contacts. Frequent touching of contaminated surfaces in public areas is therefore a potential route of SARS-CoV-2 transmission. The inanimate surfaces have often been described as a source of nosocomial infections. However, summaries on the transmissibility of coronaviruses from contaminated surfaces to induce the coronavirus disease 2019 are rare at present. This review aims to summarize data on the persistence of different coronaviruses on inanimate surfaces. The literature was systematically searched on Medline without language restrictions. All reports with experimental evidence on the duration persistence of coronaviruses on any type of surface were included. Most viruses from the respiratory tract, such as coronaviruses, influenza, SARS-CoV, or rhinovirus, can persist on surfaces for a few days. Persistence time on inanimate surfaces varied from minutes to up to one month, depending on the environmental conditions. SARS-CoV-2 can be sustained in air in closed unventilated buses for at least 30 min without losing infectivity. The most common coronaviruses may well survive or persist on surfaces for up to one month. Viruses in respiratory or fecal specimens can maintain infectivity for quite a long time at room temperature. Absorbent materials like cotton are safer than unabsorbent materials for protection from virus infection. The risk of transmission via touching contaminated paper is low. Preventive strategies such as washing hands and wearing masks are critical to the control of coronavirus disease 2019.
The world faces a severe and acute public health emergency due to the ongoing coronavirus disease 2019 (COVID-19) global pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Healthcare workers are in the front line of the COVID-19 outbreak response and are exposed to the risk of SARS-CoV-2 infection daily. Personal protective equipment (PPE) is their main defense against viral contamination; gloves, visors, face masks, and gown materials are designed to eliminate viral transfer from infected patients. Here, we review research investigating the stability of SARS-CoV-2 and similar viruses on surfaces and highlight opportunities for materials that can actively reduce SARS-CoV-2 surface contamination and associated transmission and improve PPE.
The outbreak of the corona virus disease 2019 (COVID-19) infection has spread to a large number of countries worldwide. The early diagnosis of COVID-19 is complicated by its strong transmission characteristics and no obvious symptoms in the incubation period. Due to the relatively sealed indoor environment and the existing ventilation system, the patients and doctors in the fever clinics of the major hospitals are faced with a huge risk of infection. This study aims to investigate the transport of droplet aerosols generated by both doctors and patients to seek measures to reduce the risk of infection. Taking a typical fever clinic as an object of study, two links in the actual diagnosis and treatment process are selected in this manuscript for investigation by experimental and numerical methods. The effects of different cases of coughing and talking, as well as different contact distances, on the inhalation rate of human droplet aerosols are studied. The purification capacity of the ventilation is evaluated by the analysis results of the particle diffusion track and regional concentration of the entire indoor area and breathing zones. The results show that purification of the same number of droplet aerosols and purification by ventilation work better for coughing than for talking. The best ventilation performance appeared for the case of a patient sitting and coughing (PSC), while the case of a patient lying and talking (PLT) was the worst. Corresponding measures are suggested to improve the air purification effect and reduce the risk of cross infection.
Since emerging in late 2019, SARS-CoV-2 has caused a global pandemic, and it may become an endemic human pathogen. Understanding the impact of environmental conditions on SARS-CoV-2 viability and its transmission potential is crucial to anticipating epidemic dynamics and designing mitigation strategies. Ambient temperature and humidity are known to have strong effects on the environmental stability of viruses 1 , but there is little data for SARS-CoV-2, and a general quantitative understanding of how temperature and humidity affect virus stability has remained elusive. Here, we characterise the stability of SARS-CoV-2 on an inert surface at a variety of temperature and humidity conditions, and introduce a mechanistic model that enables accurate prediction of virus stability in unobserved conditions. We find that SARS-CoV-2 survives better at low temperatures and extreme relative humidities; median estimated virus half-life was more than 24 hours at 10 °C and 40 % RH, but approximately an hour and a half at 27 °C and 65 % RH. Our results highlight scenarios of particular transmission risk, and provide a mechanistic explanation for observed superspreading events in cool indoor environments such as food processing plants. Moreover, our model predicts observations from other human coronaviruses and other studies of SARS-CoV-2, suggesting the existence of shared mechanisms that determine environmental stability across a number of enveloped viruses.
The number of studies published on COVID-19 in recent months is certainly impressive. However, there are still important gaps to know a great number of characteristics of this disease. Among these, some potential ways of transmission of the SARS-CoV-2 and the different reasons for the severity of the disease in different people. Various studies have suggested that certain air pollutants could be increasing the transmission of the coronavirus, as well as the risks of COVID-19 incidence and mortality. In the present preliminary case-study conducted in Tarragona Province (Catalonia, Spain), we studied the potential association of COVID-19 with PM10, NO2 and O3, as well as the differences in the incidence and lethality of this disease. This Province is divided into two “health regions”: Camp de Tarragona, with an important industrial complex, and Terres de l’Ebre, with a great agricultural component. In spite of the notable limitations of the current study, our preliminary findings indicate that the industrialized/urban areas of Tarragona Province show a higher incidence and mortality of COVID-19 than the agricultural/rural zones. These – and previous – results would highlight the importance of conducting specific investigations focused on directly assessing whether air pollutants such as particulate matter can act as carriers of the SARS-CoV-2. If confirmed, the recommendation on keeping the “social distance” (1.5–2 m) might need to be adapted to this situation.
We used a quantitative microbial risk assessment approach to relate log10 disinfection reductions of SARS-CoV-2 bioburden to COVID-19 infection risks. Under low viral bioburden, minimal log10 reductions may be needed to reduce infection risks for a single hand-to-fomite touch to levels lower than 1:1,000,000, as a risk comparison point. For higher viral bioburden conditions, log10 reductions of more than 2 may be needed to achieve median infection risks of less than 1:1,000,000. © 2020 Association for Professionals in Infection Control and Epidemiology, Inc.
The healthcare environment serves as one of the possible routes of transmission of epidemiologically important pathogens, but the role of the contaminated environment on SARS-CoV-2 transmission remains unclear. We reviewed survival, contamination, and transmission of SARS-CoV-2 via environmental surfaces and shared medical devices as well as environmental disinfection of COVID-19 in healthcare settings. Coronaviruses, including SARS-CoV-2, have been demonstrated to survive for hours to days on environmental surfaces depending on experimental conditions. The healthcare environment is frequently contaminated with SARS-CoV-2 RNA in most studies but without evidence of viable virus. Although direct exposure to respiratory droplets is the main transmission route of SARS-CoV-2, the contaminated healthcare environment can potentially result in transmission of SARS-CoV-2 as described with other coronaviruses such as SARS-CoV and MERS-CoV. It is important to improve thoroughness of cleaning/disinfection practice in healthcare facilities and select effective disinfectants to decontaminate inanimate surfaces and shared patient care items.
During the 2020 COVID-19 pandemic, an outbreak occurred following attendance of a symptomatic index case at a weekly rehearsal on 10 March of the Skagit Valley Chorale (SVC). After that rehearsal, 53 members of the SVC among 61 in attendance were confirmed or strongly suspected to have contracted COVID-19 and two died. Transmission by the aerosol route is likely; it appears unlikely that either fomite or ballistic droplet transmission could explain a substantial fraction of the cases. It is vital to identify features of cases such as this to better understand the factors that promote superspreading events. Based on a conditional assumption that transmission during this outbreak was dominated by inhalation of respiratory aerosol generated by one index case, we use the available evidence to infer the emission rate of aerosol infectious quanta. We explore how the risk of infection would vary with several influential factors: ventilation rate, duration of event, and deposition onto surfaces. The results indicate a best-estimate emission rate of 970 ± 390 quanta h-1 . Infection risk would be reduced by a factor of two by increasing the aerosol loss rate to 5 h-1 and shortening the event duration from 2.5 to 1 h.
During the current SARS-CoV-2 pandemic new studies are emerging daily providing novel information about sources, transmission risks and possible prevention measures. In this review, we aimed to comprehensively summarize the current evidence on possible sources for SARS-CoV-2, including evaluation of transmission risks and effectiveness of applied prevention measures. Next to symptomatic patients, asymptomatic or pre-symptomatic carriers are a possible source with respiratory secretions as the most likely cause for viral transmission. Air and inanimate surfaces may be sources; however, viral RNA has been inconsistently detected. Similarly, even though SARS-CoV-2 RNA has been detected on or in personnel protective equipment, blood, urine, eyes, the gastrointestinal tract and pets, these sources are currently thought to play a negligible role for transmission. Finally, various prevention measures such as hand washing, hand disinfection, face masks, gloves, surface disinfection or physical distancing for the healthcare setting and public are analysed for their expected protective effect.
A new coronavirus (SARS-CoV-2) has determined a pneumonia outbreak in China (Wuhan, Hubei Province) in December 2019, called COVID-19 disease. In addition to the person-to person transmission dynamic of the novel respiratory virus, it has been recently studied the role of environmental factors in accelerate SARS-CoV-2 spread and its lethality. The time being, air pollution has been identified as the largest environmental cause of disease and premature death in the world. It affects body's immunity, making people more vulnerable to pathogens. The hypothesis that air pollution, resulting from a combination of factors such as meteorological data, level of industrialization as well as regional topography, can acts both as a carrier of the infection and as a worsening factor of the health impact of COVID-19 disease, has been raised recently. With this review, we want to provide an update state of art relating the role of air pollution, in particular PM2.5, PM10 and NO2, in COVID-19 spread and lethality. The Authors, who first investigated this association, often used different research methods or not all include confounding factors whenever possible. In addition, to date incidence data are underestimated in all countries and to a lesser extent also mortality data. For this reason, the cases included in the reviewed studies cannot be considered conclusive. Although it determines important limitations for direct comparison of results, and more studies are needed to strengthen scientific evidences and support firm conclusions, major findings are consistent, highlighting the important contribution of PM2.5 and NO2 as triggering of the COVID-19 spread and lethality, and with a less extent also PM10, although the potential effect of airborne virus exposure it has not been still demonstrated.
The recent coronavirus 2019 (COVID-19) pandemic has resulted in increased hand hygiene and hand cleansing awareness. To prevent virus transmission, the Center for Disease Control (CDC) recommends frequent hand washing with soap and water. Hand hygiene products are available in a variety of forms and while each of these formulations may be effective against COVID-19, they may also alter skin barrier integrity and function. As health care workers and the general population focus on stringent hand hygiene, the American Contact Dermatitis Society (ACDS) anticipates an increase in both irritant contact and allergic contact hand dermatitis. Alcohol-based hand sanitizers with moisturizers have the least sensitizing and irritancy potential when compared to soaps and synthetic detergents. This article provides an overview of the most frequently used hand hygiene products and their associations with contact dermatitis as well as recommendations from the ACDS on how to treat and prevent further dermatitis.
The world is facing, while writing this review, a global pandemic due to one of the types of the coronaviruses (i.e., COVID-19), which is a new virus. Among the most important reasons for the transmission of infection between humans is the presence of this virus active on the surfaces and materials. Here, we addressed important questions such as do coronaviruses remain active on the inanimate surfaces? Do the types of inanimate surfaces affect the activity of coronaviruses? What are the most suitable ingredients that used to inactivate viruses? This review article addressed many of the works that were done in the previous periods on the survival of many viruses from the coronaviruses family on various surfaces such as steel, glass, plastic, Teflon, ceramic tiles, silicon rubber and stainless steel copper alloys, Al surface, sterile sponges, surgical gloves and sterile latex. The impacts of environmental conditions such as temperature and humidity were presented and discussed. The most important active ingredients that can deactivate viruses on the surfaces were reported here. We hope that these active ingredients will have the same effect on COVID-19.
The Coronavirus disease 2019 (COVID-19) is spreading around the world, representing a global pandemic, counting, as of June 5th, 2020, over 6,600,000 confirmed cases and more than 390,000 deaths, with exponentially increasing numbers. In the first half of 2020, because of the widespread of the COVID-19, researches were focused on the monitoring of SARS-CoV-2 in water, wastewater, sludge, air, and on surfaces, in order to assess the risk of contracting the viral infection from contaminated environments. So far, the survival of the novel Coronavirus out of the human body has been reported for short time periods (from hours to few days, in optimized in vitro conditions), mainly because of the need of an host organism which could consent the viral attack, and due to the weak external membrane of the virus. SARS-CoV-2 viral shedding strategies in the environment, either through animate and unanimate matrices, or exploiting the organic matter in water, wastewater, and waste in general, have been discussed in the present article. We concluded that, besides the high infectuousness of the novel Coronavirus, the transmission of the pathogen may be efficiently contained applying the adequate preventive measures (e.g., personal protection equipments, and disinfecting agents), indicated by national and international health authories.
Particulate matter, sulfur dioxide, nitrogen oxides, ozone, carbon monoxide, volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) are among the outdoor air pollutants that are major factors in diseases, causing especially adverse respiratory effects in humans. On the other hand, the role of respiratory viruses in the pathogenesis of severe respiratory infections is an issue of great importance. The present literature review was aimed at assessing the potential effects of air pollutants on the transmission and severity of respiratory viral infections. We have reviewed the scientific literature regarding the association of outdoor air pollution and respiratory viruses on respiratory diseases. Evidence supports a clear association between air concentrations of some pollutants and human respiratory viruses interacting to adversely affect the respiratory system. Given the undoubted importance and topicality of the subject, we have paid special attention to the association between air pollutants and the transmission and severity of the effects caused by the coronavirus named SARS-CoV-2, which causes the COVID-19. Although to date, and by obvious reasons, the number of studies on this issue are still scarce, most results indicate that chronic exposure to air pollutants delays/complicates recovery of patients of COVID-19 and leads to more severe and lethal forms of this disease. This deserves immediate and in-depth experimental investigations.
The severe cases of COVID-19 infections in Italy, and notably in Lombardy (mainly in Brescia and Bergamo areas), registered at the beginning of March 2020, occurred after a period of PM10 pollution, that exceeded the concentration of 50 μg/m³ (the attention limit) for several days. The two events were supposed to be correlated, also based on the limited information available about the new virus. Despite that clear indications about the role of particulate matter (PM) in the virus mechanism dispersion cannot be found in literature, some researchers supposed that PM can act as virus carrier, promoting its diffusion through the air.
This paper, for the first time, analyses the PM10 situation in Lombardy (from 10th February to 27th March 2020), several days before the sanitary emergency explosion. The data of the detected infection cases are reported and discussed parallelly. As a comparison, the situation of Piedmont, located near to the Lombardy is also presented. Data are reported for Brescia, Bergamo, Cremona, Lodi, Milano, Monza-Brianza, Pavia (Lombardy), Alessandria, Vercelli, Novara, Biella, Asti, and Torino (Piedmont). The results show that it is not possible to conclude that COVID-19 diffusion mechanism also occurs through the air, by using PM10 as a carrier. In particular, it is shown that Piedmont cities, presenting lower detected infections cases in comparison to Brescia and Bergamo in the investigated period, had most sever PM10 pollution events in comparison to Lombardy cities. This first study may serve as a reference to better understand and predict the factors affecting the COVID-19 diffusion and transmission routes, focusing on the role of air particulate matter in the atmosphere.
The COVID-19 pandemic is creating a havoc situation across the globe that modern society has ever seen. Despite of their paramount importance, the transmission routes of SARS-Cov-2 still remain debated among various sectors. Evidences compiled here strongly suggest that the COVID-19 could be transmitted via air in inadequately ventilated environments that are housing the infected by SARS-Cov-2. Existing experimental data showed that coronavirus survival was negatively impacted by ozone, high temperature and low humidity. Here, regression analysis showed that the spread of SARS-Cov-2 was reduced by increasing ambient ozone concentration level (48.83–94.67 μg/m³) (p-value = 0.039) and decreasing relative humidity (23.33–82.67%) (p-value = 0.002) and temperature (−13.17-19 °C) (p-value = 0.003) observed for Chinese cities during Jan-March 2020. Besides using these environmental implications, social distancing and wearing a mask are strongly encouraged to maximize the fight against the COVID-19 transmission. At no other time than now are the scientists in various disciplines around the world badly needed by the society to collectively confront this disastrous pandemic.